pax_global_header00006660000000000000000000000064113512714550014516gustar00rootroot0000000000000052 comment=e7d5dd923e96ce859d19de8da706f274ebb825bf gnu-standards-2010.03.11/000077500000000000000000000000001135127145500146555ustar00rootroot00000000000000gnu-standards-2010.03.11/ChangeLog000066400000000000000000000500071135127145500164310ustar00rootroot000000000000002010-02-18 Karl Berry * make-stds.texi (Standard Targets) : Avoid absolute, DESTDIR-related, target name, which fails if the target directory happens to contain spaces. Hence avoid $@, which was redundantly specified anyway. Finally, only the install-info run is POST_INSTALL, the INSTALL_DATA part is NORMAL_INSTALL. Report from Aubrey Jaffer, follow-up from Ralf Wildenhues, 11 Feb 2010 07:29:15. (Directory Variables): State that install dirs and their parents should be created before being used. (DESTDIR): Capitalize section name in the usual way. (Standard Targets) : mkinstalldirs is better found in Gnulib. 2010-02-18 Thien-Thi Nguyen (tiny change) Insert space before open-paren in C code fragments. * doc/standards.texi (Conditional Compilation): Say "if (...)", not "if( ...)". (Semantics): Say "fd = open (...)", not "fd = open(...)". 2010-02-18 Thien-Thi Nguyen (tiny change) * doc/standards.texi (Change Log Concepts): Move the "however, one line to describe change ok" from its own paragraph (following another "however..." sentence, thus losing the antecedent) into the paragraph where "need to describe full purpose of changes" is first discouraged. Also, expand the prepositional noun phrase to cover a single change. 2010-02-18 Thien-Thi Nguyen (tiny change) * doc/standards.texi (Change Log Concepts): Use three hyphens for "emdash". 2010-01-27 Karl Berry * maintain.texi (Copyright Notices): Normalize whitespace; clarify "Copyright" being in English and C-in-a-circle or (C) not being a requirement. 2010-01-24 Ralf Wildenhues * doc/make-stds.texi (Makefile Basics): corrected to sed -f sedscript, not sed -e. 2010-01-05 Karl Berry * make-stds.texi (Standard Targets): Don't explicitly mention any compression formats other than gzip. 2009-12-12 Karl Berry * maintain.texi (Automated Upload Procedure): try to be more explicit about the example gpg commands, etc. Suggestion from Ward Vandewege. 2009-12-11 Ralf Wildenhues Do not recommend world-writable directories in package tarballs. * standards.texi (Releases): change recommended directory mode to 755, include justification and refer to original text; following CVE-2009-4029. Report by Jim Meyering. 2009-11-20 Karl Berry * standards.texi (Preface), * maintain.texi (Preface): mention gnustandards-commit mailing list. 2009-09-14 Karl Berry * standards.texi (Configuration): Environment variables should be supported for configure as well as options. 2009-07-24 Karl Berry * maintain.texi (Web Pages): reorganize into subnodes. (Old Versions): mention savannah-announce mailing list. (About This Document): mention fsfstatus url. No substantive changes in all of that. 2009-06-07 Karl Berry * standards.texi (Man Pages): refer to the all-permissive license in maintain.texi instead of quoting it. 2009-04-29 Karl Berry * maintain.texi (License Notices for Other Files): second sentence about no warranty, per legal advice. 2009-04-16 Karl Berry * standards.texi (Releases): COPYING.LESSER, not COPYING.LIB. Report from Simon Ward, 15 Apr 2009 21:57:53. 2009-03-12 Karl Berry * maintain.texi (Announcements): suggestions for announcement contents. 2009-03-04 Karl Berry * gnu-oids.texi: allocate .6 to GNU Shishi for Simon Josefsson. 2009-02-06 Karl Berry * standards.texi (--help): tweak punctuation of sample output. 2009-02-05 Karl Berry * maintain.texi (Automated Upload Registration): more hints about how to use gpg. 2009-01-26 Karl Berry * standards.texi (--help): recommend including the package's home page and gnu.org/gethelp. 2009-01-18 Karl Berry * maintain.texi (Standalone directives): clarify that `rmsymlink' fails unless the symlink exists, but `symlink' overwrites an existing symlink. Information from Sergey Poznyakoff. 2008-12-31 Karl Berry * maintain.texi (License Notices for Documentation): clarify that long and/or FSF-published manuals should include the GPL. 2008-11-14 Karl Berry * maintain.texi (Automated Upload Procedure): mention that gnupload can now delete files as well as upload them. 2008-11-10 Karl Berry * fdl.texi: update to 1.3 file. Missed this earlier. 2008-11-08 Karl Berry * maintain.texi (License Notices): explicitly mention that there is no need for a plain text version of the FDL, e.g., no COPYING.DOC. 2008-11-07 Karl Berry * make-stds.texi (Utilities in Makefiles): add tr. Request from Eric Blake, bug-standards 04 Nov 2008 06:21:05 (and ff). 2008-11-06 Karl Berry * maintain.texi, standards.texi, make-stds.texi: upgrade license to FDL 1.3+, including example text in maintain.texi. 2008-11-04 Karl Berry * gnu-oids.texi: correct comment; included in standards, not maintain. 2008-10-31 Karl Berry * standards.texi (OID Allocations): new node. * gnu-oids.texi: new file with current allocations, from Werner Koch. 2008-10-13 Karl Berry * maintain.texi (Announcements): mention planet.gnu.org and savannah news feeds. Suggestion from Ralf Wildenhues. 2008-08-04 Karl Berry * maintain.texi (Automated Upload Procedure): mention gnupload and ncftpput[-ftp] for doing the gnu.org uploads. 2008-08-01 Karl Berry * maintain.texi: mostly suggestions from dbe based on dubbing mail: mention coding standards and mentors@gnu.org; update accounts info url; mention gnu.org/people/people.html; more discussion of mailing lists; Free Software Directory entries. 2008-07-27 Karl Berry * standards.texi (Configuration): make clear that this is the specification and that autoconf/automake are not the required implementation. 2008-07-09 Karl Berry * maintain.texi (Clean Ups): correct section title (Tips and Conventions) in elisp reference. 2008-06-10 Karl Berry * standards.texi (Option Table) <--file>: -f is --file in sed, too. <--reference>: touch -r is this, not --file. Use @code{make} for consistency with other program names. bug-standards mail from Iain Calder, 01 Jun 2008 05:23:10. 2008-05-05 Karl Berry * standards.texi (Source Language): mention GTK+ bindings in Guile. 2008-04-25 Karl Berry * make-stds.texi (Standard Targets): ok to support other free compression formats. * maintain.texi (Free Software and Open Source): update url to http://www.gnu.org/philosophy/open-source-misses-the-point.html. 2008-04-08 Ralf Wildenhues and Karl Berry * make-stds.texi (General Conventions for Makefiles): more notes on portability. 2008-03-30 Ralf Wildenhues * standards.texi: Fix links to config and gnulib repos, add some `@/' to url's. 2008-03-21 Karl Berry * maintain.texi (Copyright Notices): missing "of". 2008-03-14 Karl Berry * maintain.texi (Copyright Papers): discuss disclaim.translation and the Translation Project. 2008-02-24 Karl Berry * maintain.texi (Automated Upload Registration): avoid double "also". 2008-02-23 Karl Berry * standards.texi (Configuration): support the options to set the directory variables, such as --prefix and --exec-prefix. 2008-02-14 Karl Berry * make-stds.texi (Utilities in Makefiles): Don't imply that gzip is the only compression program that can be used in make dist. 2008-02-11 Richard Stallman * maintain.texi (Copyright Papers): Distinguish personal disclaimers from employer's disclaimers. 2008-01-30 Richard Stallman * maintain.texi (License Notices for Documentation): new Back-Cover Text. 2008-01-19 Karl Berry * maintain.texi (Hosting): subversions.gnu.org is now savannah.gnu.org; recommend using ftp.gnu.org a little more strongly. (Announcements): recommend using info-gnu more strongly. 2008-01-17 Karl Berry * maintain.texi (GNU Free Documentation License): new node; change license of document, after discussion with rms, Eben, and Brett. 2008-01-05 Karl Berry * maintain.texi (Automated Upload Registration): first create an account at savannah. (Requested by sysadmin.) 2007-12-30 Karl Berry * (License Notices): move mention of licensing@gnu.org to a more general place. (License Notices for Documentation), (Free Software and Open Source): consistently put punctuation outside quotes (except when it's part of the quote). (GNU and Linux): Typo. 2007-12-30 Tim Retout * maintain.texi (Legally Significant Changes): use gender-neutral pronouns. 2007-11-29 Karl Berry * make-stds.texi (Command Variables): allow (but do not require) installing multiple files at once. Request from Akim Demaille. 2007-11-24 Karl Berry * maintain.texi (Legal Matters): remove trailing whitespace. 2007-11-14 Ward Vandewege * doc/maintain.texi (FTP Upload Directive File - v1.1): Add example how to archive a directory. 2007-11-04 Sergey Poznyakoff * maintain.texi (Web Pages): Mention the --texi2html option to gendocs.sh. 2007-10-10 Karl Berry * maintain.texi, * standards.texi: Fix a few typos. 2007-10-08 Richard Stallman * maintain.texi (Web Pages): GNU package web sites should run on free software exclusively. (Ethical and Philosophical Consideration): Modernize the passage about patents. * standards.texi: Clarify the issues of references to non-free programs and documentation. 2007-10-06 Karl Berry * maintain.texi (Stepping Down), (Canonical License Sources), (Old Versions): Mention Git, and generalize mentions of source control. Idea from: Benoit Sigoure, bug-gnulib mail 4 Oct 2007 18:47:44. 2007-09-25 Karl Berry * maintain.texi (Automated Upload Procedure): Incomplete uploaded files now deleted after 24 hours; info from Ward Vandewege, 25 Sep 2007 15:20:53. 2007-09-23 Karl Berry * standards.texi (System Portability): Abbreviating Windows to "un" seems like a typo. Reported by John Darrington, 23 Sep 2007 03:32:24. 2007-09-20 Karl Berry * maintain.texi (License Notices): Wrong @menu punctuation for Texinfo. 2007-09-09 Karl Berry * standards.texi (References): Missing word "to". 2007-09-05 Karl Berry * make-stds.texi (Utilities in Makefiles): Add awk to allowed utilities list. Requested by Ralf Wildenhues. 2007-08-18 Karl Berry * make-stds.texi (DESTDIR): Must be an absolute file name. Requested by Ralf Wildenhues. 2007-07-25 Karl Berry * maintain.texi (License Notices for Code): More punctuation fixes from Eric Blake. 2007-07-24 Karl Berry * maintain.texi (License Notices for Code): Sync wording with gpl-3.0.texi. Reported by Eric Blake. 2007-07-22 Karl Berry * standards.texi (all @menus): Consistently capitalize and punctuate. * standards.texi (GNU Free Documentation License): Make @appendix, replacing "Copying This Manual". Reported by Paul Eggert. * fdl.texi: Update to new version (without @node). 2007-07-09 Karl Berry * maintain.texi (License Notices): Split up into new nodes: Canonical License Sources, License Notices for Code, License Notices for Documentation, License Notices for Other Files. Also, update for GPLv3. Also, clarify that the Cover Texts are only required for large manuals and/or those that FSF publishes on paper. 2007-07-07 Karl Berry * maintain.texi (License Notices, Proofreading): use ``...''' instead of "...". Double space where appropriate. 2007-06-27 Karl Berry * standards.texi (--version): use / for exceptions, make version number location clearer. 2007-06-26 Karl Berry * standards.texi (--version, --help): new nodes, split from Command-Line Interfaces. Include table of license abbreviations and new recommended --version output. * maintain.texi (License Notices): new Back-Cover Text. 2007-05-23 Karl Berry * maintain.texi (Copying from Other Packages): mention writing license statements when they were omitted by the original authors. 2007-03-08 Karl Berry * maintain.texi (Preface): We don't have or update /gd/gnuorg/maintain.tar.gz any more, and it seems unnecessary to reinstate it. Reported by Thomas Schwinge, ticket 330574. 2007-01-22 Karl Berry * standards.texi (References): Er, "free software", not "freely available". 2007-01-21 Karl Berry * standards.texi (References): Update Java reference, add mplayer issues. Correct a -- to ---. * maintain.texi (Ethical and Philosophical Consideration): GIF patents have expired, so just mention the general principle. 2006-12-05 Karl Berry * maintain.texi (Web Pages): GIF patents expired, tweak wording. Consistently use a single space after @node and @section. 2006-11-15 Karl Berry * standards.texi: core -> memory, throughout. (CPU Portability): show correct example of calling write on a char value; thanks to Paul Eggert for the code. Both of these suggestions from Eugene Y. Vasserman. 2006-10-18 Karl Berry * maintain.texi (Automated Upload Procedure): texinfo typo. 2006-10-09 Karl Berry * maintain.texi (Recording Contributors): typo. 2006-04-23 Richard Stallman * maintain.texi (Recording Contributors): Explain updating AUTHORS from change log. (Copying from Other Packages): New node. 2006-08-19 Ralf Wildenhues and Bruno Haible * make-stds.texi (menu): Adjust to changed node order. (DESTDIR): This variable is not specified to the configure script. * standards.texi (Configuration): Document that configure should accept arguments of the form `VARIABLE=VALUE' and why this is preferable to environment variables. 2006-08-14 Paul Eggert * make-stds.texi, standards.texi: Update FDL version number from 1.1 to 1.2. 2006-07-09 Karl Berry * make-stds.texi: attempt to clarify that [install-] html/ps/pdf/dvi targets should exist, but might not do anything. Suggestions from Eric Blake and Bruno Haible. 2006-07-09 * maintain.texi, make-stds.texi, standards.texi: Fix some typos. 2006-05-24 Bruno Haible * standards.texi (Internationalization): Change the example with plurals to use the ngettext function, and move it to the end. Add a new example showing the need for entire sentences. 2006-05-09 Karl Berry * make-stds.texi (DESTDIR): new node, moving text. (Directory variables): mention that not all variables might be implemented. 2006-04-23 Richard Stallman * standards.texi (GNU Manuals): Document that we reject the Unix convention of writing `()' after function names. Say put basic topics first. Clarify. 2006-04-09 Karl Berry * standards.texi (Formatting Your Source Code): mislabeled traditional C example as Standard C. From Paul E. * standards.texi: use @/ in url's to avoid some overfull lines. 2006-04-06 Ralf Wildenhues * make-stds.texi: Bump copyright year. (Command Variables, Directory Variables): Fix spelling `filesystem' -> `file system'. 2006-03-22 Karl Berry * maintain.texi (License Notices): the FDL is 1.2 now, not 1.1. Also remove trailing whitespace. From Paul Eggert. 2006-03-10 Karl Berry * maintain.texi (License Notices): there is no (b), should be (a). From Paul Eggert. (Legal Matters): the copyright request forms are now in gnulib as well. 2006-02-13 Karl Berry * standards.texi (Command-Line Interfaces): link to Copyright Notices in maintain.texi; suggestion from Eli. 2006-02-08 Karl Berry * standards.texi (Non-GNU Standards): new section. 2006-01-09 Karl Berry * standards.texi (Releases): mention http://www.gnu.org/philosophy/free-doc.html. Suggested by Alfred Szmidt. 2006-01-01 Karl Berry * maintain.texi (Copyright Notices): keep gnulib files as they are; more explanatory description (from Bruno) about the new rule. 2005-12-25 Karl Berry * standards.texi (Formatting): column one, not zero, per elsewhere in the doc. From Kyle , 15 Dec 2005 15:50:04 -0800. (Quote Characters): ASCII apparently considered ` an actual left quote, and it got messed up later. * maintain.texi (Copyright Notices): update all files at once; copyright notices may be split over several lines. 2005-12-06 Karl Berry * maintain.texi (Copyright Notices): new, simpler rules, from rms and lawyers. 2005-10-07 Paul Eggert * standards.texi (CPU Portability): Don't mention just IA-64, as the same problem occurs on AMD64 and EM64T as well. Just say "64-bit programs on Microsoft Windows" so that we needn't track Microsoft's releases so closely. 2005-08-18 Karl Berry * standards.texi (Character set): new section, preferring ASCII. (Quote characters): new section, preferring `...' (despite standards) in the C locale. * standards.texi (Configuration): New url for config.guess and config.sub. * standards.texi (Comments): Mention that the program comment should be in the file with the "main" function of the program. 2005-06-01 Karl Berry * standards.texi: various typos and corrections reported by Ming Kin Lai, 24 May 2005 00:38:00 -0700. 2005-02-13 Karl Berry * make-stds.texi (Directory Variables): clarify descriptions for libexecdir, datarootdir, and datadir. Thanks to Alexandre and Alfred Szmidt. 2005-01-27 Paul Eggert * make-stds.texi: spurious @c in copyright statement. 2005-01-04 Alexandre Duret-Lutz * maintain.texi (License Notices): Allow all-permissive license for third-party Autoconf macros. 2005-01-04 Richard Stallman * maintain.texi (Legal Matters): timing info. 2005-01-01 Alexandre Duret-Lutz * make-stds.texi (Install Command Categories): Correct the pre-install.awk example. `make -s' needed, typos in awk script. 2004-12-30 Paul Eggert * standards.texi (CPU Portability): update for modern machines, especially varargs example. 2004-12-06 Alexandre Duret-Lutz * make-stds.texi (Standard Targets): let clean targets remove anything that's normally installed. 2004-12-03 Karl Berry * make-stds.texi (Command Line Interfaces): --machine is used in uname. Reported to gnu@gnu.org. 2004-11-29 Karl Berry * standards.texi (Man Pages): use all-permissive license. (Source Language): typo - language not languge. * make-stds.texi (Directory Variables) : new variables. {datadir}: spelling error in description. (Standard Targets) : new targets. Thanks to Alexandre Duret-Lutz, Akim Demaille, and Bruno Haible for extensive comments on this text. * maintain.texi (Automated Upload Procedure): get msg on successful upload, too. (Copyright Papers): typo - missing verb. Copyright (C) 2004, 2005 Free Software Foundation, Inc. Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. gnu-standards-2010.03.11/README000066400000000000000000000026351135127145500155430ustar00rootroot00000000000000$Id: README,v 1.4 2008/02/13 01:07:59 karl Exp $ This is the README file for the gnustandards project. Copyright (C) 2004, 2005, 2006, 2008 Free Software Foundation, Inc. Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. This hierarchy contains the canonical sources for the "GNU Coding Standards" and "Information for GNU Maintainers" documents. All changes must be approved by rms. Formatted versions are on the GNU web site: http://www.gnu.org/prep/ Copies of these sources are maintained in the gnulib project (http://savannah.gnu.org/projects/gnulib) for convenience of the maintainers who already check out gnulib. If you're interested in these, you might also be interested in the additional "Gnits" standards. They are completely unofficial and no longer updated, but go into somewhat more detail in some areas. They're available as part of the GNU Womb: http://savannah.gnu.org/cgi-bin/viewcvs/womb/gnits/ cvs -d:ext:anoncvs@cvs.gnu.org:/cvsroot/womb co gnits To update the manuals, see the work.m and work.s directories here. Each has a GNUmakefile with assorted targets and comments. They use the gendocs.sh script, which is in Texinfo CVS on savannah, which in turn needs a file gendocs_template, also in Texinfo CVS: http://cvs.savannah.gnu.org/viewcvs/texinfo/util/?root=texinfo gnu-standards-2010.03.11/fdl.texi000066400000000000000000000560151135127145500163240ustar00rootroot00000000000000@c The GNU Free Documentation License. @center Version 1.3, 3 November 2008 @c This file is intended to be included within another document, @c hence no sectioning command or @node. @display Copyright @copyright{} 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. @uref{http://fsf.org/} Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. @end display @enumerate 0 @item PREAMBLE The purpose of this License is to make a manual, textbook, or other functional and useful document @dfn{free} in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others. This License is a kind of ``copyleft'', which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software. We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference. @item APPLICABILITY AND DEFINITIONS This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The ``Document'', below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as ``you''. You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law. A ``Modified Version'' of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language. A ``Secondary Section'' is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them. The ``Invariant Sections'' are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none. The ``Cover Texts'' are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words. A ``Transparent'' copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not ``Transparent'' is called ``Opaque''. Examples of suitable formats for Transparent copies include plain @sc{ascii} without markup, Texinfo input format, La@TeX{} input format, @acronym{SGML} or @acronym{XML} using a publicly available @acronym{DTD}, and standard-conforming simple @acronym{HTML}, PostScript or @acronym{PDF} designed for human modification. Examples of transparent image formats include @acronym{PNG}, @acronym{XCF} and @acronym{JPG}. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, @acronym{SGML} or @acronym{XML} for which the @acronym{DTD} and/or processing tools are not generally available, and the machine-generated @acronym{HTML}, PostScript or @acronym{PDF} produced by some word processors for output purposes only. The ``Title Page'' means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, ``Title Page'' means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text. The ``publisher'' means any person or entity that distributes copies of the Document to the public. A section ``Entitled XYZ'' means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as ``Acknowledgements'', ``Dedications'', ``Endorsements'', or ``History''.) To ``Preserve the Title'' of such a section when you modify the Document means that it remains a section ``Entitled XYZ'' according to this definition. The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License. @item VERBATIM COPYING You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3. You may also lend copies, under the same conditions stated above, and you may publicly display copies. @item COPYING IN QUANTITY If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects. If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages. If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public. It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document. @item MODIFICATIONS You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version: @enumerate A @item Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission. @item List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement. @item State on the Title page the name of the publisher of the Modified Version, as the publisher. @item Preserve all the copyright notices of the Document. @item Add an appropriate copyright notice for your modifications adjacent to the other copyright notices. @item Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below. @item Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice. @item Include an unaltered copy of this License. @item Preserve the section Entitled ``History'', Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled ``History'' in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence. @item Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the ``History'' section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission. @item For any section Entitled ``Acknowledgements'' or ``Dedications'', Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein. @item Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles. @item Delete any section Entitled ``Endorsements''. 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If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work. In the combination, you must combine any sections Entitled ``History'' in the various original documents, forming one section Entitled ``History''; likewise combine any sections Entitled ``Acknowledgements'', and any sections Entitled ``Dedications''. You must delete all sections Entitled ``Endorsements.'' @item COLLECTIONS OF DOCUMENTS You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects. You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document. @item AGGREGATION WITH INDEPENDENT WORKS A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an ``aggregate'' if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document. If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate. @item TRANSLATION Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail. If a section in the Document is Entitled ``Acknowledgements'', ``Dedications'', or ``History'', the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title. @item TERMINATION You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License. However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it. @item FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See @uref{http://www.gnu.org/copyleft/}. Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License ``or any later version'' applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document. @item RELICENSING ``Massive Multiauthor Collaboration Site'' (or ``MMC Site'') means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can edit is an example of such a server. A ``Massive Multiauthor Collaboration'' (or ``MMC'') contained in the site means any set of copyrightable works thus published on the MMC site. ``CC-BY-SA'' means the Creative Commons Attribution-Share Alike 3.0 license published by Creative Commons Corporation, a not-for-profit corporation with a principal place of business in San Francisco, California, as well as future copyleft versions of that license published by that same organization. ``Incorporate'' means to publish or republish a Document, in whole or in part, as part of another Document. An MMC is ``eligible for relicensing'' if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008. The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing. @end enumerate @page @heading ADDENDUM: How to use this License for your documents To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page: @smallexample @group Copyright (C) @var{year} @var{your name}. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. @end group @end smallexample If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the ``with@dots{}Texts.'' line with this: @smallexample @group with the Invariant Sections being @var{list their titles}, with the Front-Cover Texts being @var{list}, and with the Back-Cover Texts being @var{list}. @end group @end smallexample If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation. If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software. @c Local Variables: @c ispell-local-pdict: "ispell-dict" @c End: gnu-standards-2010.03.11/gnu-oids.texi000066400000000000000000000033361135127145500173020ustar00rootroot00000000000000@c This table of OID's is included in the GNU Coding Standards. @c @c Copyright 2008, 2009 Free Software Foundation, Inc. @c @c Copying and distribution of this file, with or without modification, @c are permitted in any medium without royalty provided the copyright @c notice and this notice are preserved. @c @c When adding new OIDs, please add them also to @c http://www.alvestrand.no/objectid/ (except it gets an internal @c server error, so never mind) @c (Our page is http://www.alvestrand.no/objectid/1.3.6.1.4.1.11591.html.) 1.3.6.1.4.1.11591 GNU 1.3.6.1.4.1.11591.1 GNU Radius 1.3.6.1.4.1.11591.2 GnuPG 1.3.6.1.4.1.11591.2.1 notation 1.3.6.1.4.1.11591.2.1.1 pkaAddress 1.3.6.1.4.1.11591.3 GNU Radar 1.3.6.1.4.1.11591.4 GNU GSS @c Added 2008-10-24 on request from Sergey Poznyakoff 1.3.6.1.4.1.11591.5 GNU Mailutils @c Added 2009-03-03 on request from Simon Josefsson 1.3.6.1.4.1.11591.5 GNU Shishi 1.3.6.1.4.1.11591.12 digestAlgorithm 1.3.6.1.4.1.11591.12.2 TIGER/192 1.3.6.1.4.1.11591.13 encryptionAlgorithm 1.3.6.1.4.1.11591.13.2 Serpent 1.3.6.1.4.1.11591.13.2.1 Serpent-128-ECB 1.3.6.1.4.1.11591.13.2.2 Serpent-128-CBC 1.3.6.1.4.1.11591.13.2.3 Serpent-128-OFB 1.3.6.1.4.1.11591.13.2.4 Serpent-128-CFB 1.3.6.1.4.1.11591.13.2.21 Serpent-192-ECB 1.3.6.1.4.1.11591.13.2.22 Serpent-192-CBC 1.3.6.1.4.1.11591.13.2.23 Serpent-192-OFB 1.3.6.1.4.1.11591.13.2.24 Serpent-192-CFB 1.3.6.1.4.1.11591.13.2.41 Serpent-256-ECB 1.3.6.1.4.1.11591.13.2.42 Serpent-256-CBC 1.3.6.1.4.1.11591.13.2.43 Serpent-256-OFB 1.3.6.1.4.1.11591.13.2.44 Serpent-256-CFB 1.3.6.1.4.1.11591.14 CRC algorithms 1.3.6.1.4.1.11591.14.1 CRC 32 gnu-standards-2010.03.11/maintain.texi000066400000000000000000002467321135127145500173660ustar00rootroot00000000000000\input texinfo.tex @c -*-texinfo-*- @c %**start of header @setfilename maintain.info @settitle Information for Maintainers of GNU Software @c For double-sided printing, uncomment: @c @setchapternewpage odd @c This date is automagically updated when you save this file: @set lastupdate January 27, 2010 @c %**end of header @dircategory GNU organization @direntry * Maintaining: (maintain). Maintaining GNU software. @end direntry @setchapternewpage off @c Put everything in one index (arbitrarily chosen to be the concept index). @syncodeindex fn cp @syncodeindex pg cp @copying Information for maintainers of GNU software, last updated @value{lastupdate}. Copyright @copyright{} 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. @quotation Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. @end quotation @end copying @titlepage @title Information for Maintainers of GNU Software @author Richard Stallman @author last updated @value{lastupdate} @page @vskip 0pt plus 1filll @insertcopying @end titlepage @contents @ifnottex @node Top @top Version @insertcopying @end ifnottex @menu * Preface:: * Stepping Down:: * Recruiting Developers:: * Legal Matters:: * Clean Ups:: * Platforms:: * Mail:: * Old Versions:: * Distributions:: * Web Pages:: * Ethical and Philosophical Consideration:: * Terminology:: * Hosting:: * Free Software Directory:: * Using the Proofreaders List:: * GNU Free Documentation License:: * Index:: @end menu @node Preface @chapter About This Document This file contains guidelines and advice for someone who is the maintainer of a GNU program on behalf of the GNU Project. Everyone is entitled to change and redistribute GNU software; you need not pay attention to this file to get permission. But if you want to maintain a version for widespread distribution, we suggest you follow these guidelines. If you would like to be a GNU maintainer, then it is essential to follow these guidelines. In addition to this document, please read and follow the GNU Coding Standards (@pxref{Top, , Contents, standards, GNU Coding Standards}). @cindex @code{gnustandards-commit@@gnu.org} mailing list If you want to receive diffs for every change to these GNU documents, join the mailing list @code{gnustandards-commit@@gnu.org}, via the web interface at @url{http://lists.gnu.org/mailman/listinfo/gnustandards-commit}. Archives are also available there. @cindex @code{maintainers@@gnu.org} email address Please send corrections or suggestions for this document to @email{bug-standards@@gnu.org}. If you make a suggestion, please include a suggested new wording for it, to help us consider the suggestion efficiently. We prefer a context diff to the @file{maintain.texi} file, but if you don't have that file, you can make a context diff for some other version of this document, or propose it in any way that makes it clear. @cindex @code{mentors@@gnu.org} mailing list If you have general questions or encounter a situation where it isn't clear what to do, you can ask @email{mentors@@gnu.org}, which is a list of a few experienced GNU contributors who have offered to answer questions for new maintainers. The directory @file{/gd/gnuorg} mentioned throughout this document is found on the GNU file server, currently @code{fencepost.gnu.org}; if you are the maintainer of a GNU package, you should have an account there. See @url{http://www.gnu.org/software/README.accounts.html} if you don't have one. (You can also ask for accounts for people who help you a large amount in working on the package.) If on occasion you find that any GNU computer systems (@code{fencepost.gnu.org}, @code{ftp.gnu.org}, @code{savannah.gnu.org}, or others) seem to be down, you can check the current status at @url{http://identi.ca/group/fsfstatus}. Most likely the problem, if it is at the FSF end, is already being worked on. @cindex Piercy, Marge This document uses the gender-neutral third-person pronouns ``person'', ``per'', ``pers'' and ``perself'' which were promoted, and perhaps invented, by Marge Piercy in @cite{Woman on the Edge of Time}. They are used just like ``she'', ``her'', ``hers'' and ``herself'', except that they apply equally to males and females. For example, ``Person placed per new program under the GNU GPL, to let the public benefit from per work, and to enable per to feel person has done the right thing.'' This release of the GNU Maintenance Instructions was last updated @value{lastupdate}. @node Stepping Down @chapter Stepping Down With good fortune, you will continue maintaining your package for many decades. But sometimes for various reasons maintainers decide to step down. If you're the official maintainer of a GNU package and you decide to step down, please inform the GNU Project (@email{maintainers@@gnu.org}). We need to know that the package no longer has a maintainer, so we can look for and appoint a new maintainer. If you have an idea for who should take over, please tell @email{maintainers@@gnu.org} your suggestion. The appointment of a new maintainer needs the GNU Project's confirmation, but your judgment that a person is capable of doing the job will carry a lot of weight. As your final act as maintainer, it would be helpful to set up the package under @code{savannah.gnu.org} if it is not there already (@pxref{Old Versions}). This will make it much easier for the new maintainer to pick up where you left off and will ensure that the source tree is not misplaced if it takes us a while to find a new maintainer. @node Recruiting Developers @chapter Recruiting Developers Unless your package is a fairly small, you probably won't do all the work on it yourself. Most maintainers recruit other developers to help. Sometimes people will offer to help. Some of them will be capable, while others will not. It's up to you to determine who provides useful help, and encourage those people to participate more. Some of the people who offer to help will support the GNU Project, while others may be interested for other reasons. Some will support the goals of the Free Software Movement, but some may not. They are all welcome to help with the work---we don't ask people's views or motivations before they contribute to GNU packages. As a consequence, you cannot expect all contributors to support the GNU Project, or to have a concern for its policies and standards. So part of your job as maintainer is to exercise your authority on these points when they arise. No matter how much of the work other people do, you are in charge of what goes in the release. When a crucial point arises, you should calmly state your decision and stick to it. Sometimes a package has several co-maintainers who share the role of maintainer. Unlike developers who help, co-maintainers have actually been appointed jointly as the maintainers of the package, and they carry out the maintainer's functions together. If you would like to propose some of your developers as co-maintainers, please contact @email{maintainers@@gnu.org}. We're happy to acknowledge all major contributors to GNU packages on the @url{http://www.gnu.org/people/people.html} web page. Please send an entry for yourself to @email{webmasters@@gnu.org}, and feel free to suggest it to other significant developers on your package. @node Legal Matters @chapter Legal Matters @cindex legal matters This chapter describes procedures you should follow for legal reasons as you maintain the program, to avoid legal difficulties. @menu * Copyright Papers:: * Legally Significant:: * Recording Contributors:: * Copying from Other Packages:: * Copyright Notices:: * License Notices:: * External Libraries:: @end menu @node Copyright Papers @section Copyright Papers @cindex copyright papers If you maintain an FSF-copyrighted package certain legal procedures are required when incorporating legally significant changes written by other people. This ensures that the FSF has the legal right to distribute the package, and the standing to defend its GPL-covered status in court if necessary. @strong{Before} incorporating significant changes, make sure that the person who wrote the changes has signed copyright papers and that the Free Software Foundation has received and signed them. We may also need an employer's disclaimer from the person's employer. @cindex data base of GNU copyright assignments To check whether papers have been received, look in @file{/gd/gnuorg/copyright.list}. If you can't look there directly, @email{fsf-records@@gnu.org} can check for you. Our clerk can also check for papers that are waiting to be entered and inform you when expected papers arrive. @cindex @file{/gd/gnuorg} directory @c This paragraph intentionally duplicates information given @c near the beginning of the file--to make sure people don't miss it. The directory @file{/gd/gnuorg} is found on the GNU machines, currently @code{fencepost.gnu.org}; if you are the maintainer of a GNU package, you should have an account on them. Contact @email{accounts@@gnu.org} if you don't have one. (You can also ask for accounts for people who help you a large amount in working on the package.) In order for the contributor to know person should sign papers, you need to ask per for the necessary papers. If you don't know per well, and you don't know that person is used to our ways of handling copyright papers, then it might be a good idea to raise the subject with a message like this: @quotation Would you be willing to assign the copyright to the Free Software Foundation, so that we could install it in @var{program}? @end quotation @noindent or @quotation Would you be willing to sign a copyright disclaimer to put this change in the public domain, so that we can install it in @var{program}? @end quotation If the contributor wants more information, you can send per @file{/gd/gnuorg/conditions.text}, which explains per options (assign vs.@: disclaim) and their consequences. Once the conversation is under way and the contributor is ready for more details, you should send one of the templates that are found in the directory @file{/gd/gnuorg/Copyright/}; they are also available from the @file{doc/Copyright/} directory of the @code{gnulib} project at @url{http://savannah.gnu.org/projects/gnulib}. This section explains which templates you should use in which circumstances. @strong{Please don't use any of the templates except for those listed here, and please don't change the wording.} Once the conversation is under way, you can send the contributor the precise wording and instructions by email. Before you do this, make sure to get the current version of the template you will use! We change these templates occasionally---don't keep using an old version. For large changes, ask the contributor for an assignment. Send per a copy of the file @file{request-assign.changes}. (Like all the @samp{request-} files, it is in @file{/gd/gnuorg/Copyright} and in @code{gnulib}.) For medium to small changes, request a personal disclaimer by sending per the file @file{request-disclaim.changes}. If the contributor is likely to keep making changes, person might want to sign an assignment for all per future changes to the program. So it is useful to offer per that alternative. If person wants to do it that way, send per the @file{request-assign.future}. When you send a @file{request-} file, you don't need to fill in anything before sending it. Just send the file verbatim to the contributor. The file gives per instructions for how to ask the FSF to mail per the papers to sign. The @file{request-} file also raises the issue of getting an employer's disclaimer from the contributor's employer. When the contributor emails the form to the FSF, the FSF sends per papers to sign. If person signs them right away, the whole process takes about two weeks--mostly waiting for letters to go back and forth. For less common cases, we have template files you should send to the contributor. Be sure to fill in the name of the person and the name of the program in these templates, where it says @samp{NAME OF PERSON} and @samp{NAME OF PROGRAM}, before sending; otherwise person might sign without noticing them, and the papers would be useless. Note that in some templates there is more than one place to put the name of the program or the name of the person; be sure to change all of them. All the templates raise the issue of an employer's disclaimer as well. @cindex legal papers for changes in manuals You do not need to ask for separate papers for a manual that is distributed only in the software package it describes. But if we sometimes distribute the manual separately (for instance, if we publish it as a book), then we need separate legal papers for changes in the manual. For smaller changes, use @file{disclaim.changes.manual}; for larger ones, use @file{assign.changes.manual}. To cover both past and future changes to a manual, you can use @file{assign.future.manual}. For a translation of a manual, use @file{assign.translation.manual}. For translations of program strings (as used by GNU Gettext, for example; @pxref{Internationalization,,,standards,GNU Coding Standards}), use @file{disclaim.translation}. If you make use of the Translation Project (@url{http://translationproject.org}) facilities, please check with the TP coordinators that they have sent the contributor the papers; if they haven't, then you should send the papers. In any case, you should wait for the confirmation from the FSF that the signed papers have been received and accepted before integrating the new contributor's material, as usual. If a contributor is reluctant to sign an assignment for a large change, and is willing to sign a disclaimer instead, that is acceptable, so you should offer this alternative if it helps you reach agreement. We prefer an assignment for a larger change, so that we can enforce the GNU GPL for the new text, but a disclaimer is enough to let us use the text. If you maintain a collection of programs, occasionally someone will contribute an entire separate program or manual that should be added to the collection. Then you can use the files @file{request-assign.program}, @file{disclaim.program}, @file{assign.manual}, and @file{disclaim.manual}. We very much prefer an assignment for a new separate program or manual, unless it is quite small, but a disclaimer is acceptable if the contributor insists on handling the matter that way. If a contributor wants the FSF to publish only a pseudonym, that is ok. The contributor should say this, and state the desired pseudonym, when answering the @file{request-} form. The actual legal papers will use the real name, but the FSF will publish only the pseudonym. When using one of the other forms, fill in the real name but ask the contributor to discuss the use of a pseudonym with @email{assign@@gnu.org} before sending back the signed form. @strong{Although there are other templates besides the ones listed here, they are for special circumstances; please do not use them without getting advice from @email{assign@@gnu.org}.} If you are not sure what to do, then please ask @email{assign@@gnu.org} for advice; if the contributor asks you questions about the meaning and consequences of the legal papers, and you don't know the answers, you can forward them to @email{assign@@gnu.org} and we will answer. @strong{Please do not try changing the wording of a template yourself. If you think a change is needed, please talk with @email{assign@@gnu.org}, and we will work with a lawyer to decide what to do.} @node Legally Significant @section Legally Significant Changes If a person contributes more than around 15 lines of code and/or text that is legally significant for copyright purposes, we need copyright papers for that contribution, as described above. A change of just a few lines (less than 15 or so) is not legally significant for copyright. A regular series of repeated changes, such as renaming a symbol, is not legally significant even if the symbol has to be renamed in many places. Keep in mind, however, that a series of minor changes by the same person can add up to a significant contribution. What counts is the total contribution of the person; it is irrelevant which parts of it were contributed when. Copyright does not cover ideas. If someone contributes ideas but no text, these ideas may be morally significant as contributions, and worth giving credit for, but they are not significant for copyright purposes. Likewise, bug reports do not count for copyright purposes. When giving credit to people whose contributions are not legally significant for copyright purposes, be careful to make that fact clear. The credit should clearly say they did not contribute significant code or text. When people's contributions are not legally significant because they did not write code, do this by stating clearly what their contribution was. For instance, you could write this: @example /* * Ideas by: * Richard Mlynarik (1997) * Masatake Yamato (1999) */ @end example @noindent @code{Ideas by:} makes it clear that Mlynarik and Yamato here contributed only ideas, not code. Without the @code{Ideas by:} note, several years from now we would find it hard to be sure whether they had contributed code, and we might have to track them down and ask them. When you record a small patch in a change log file, first search for previous changes by the same person, and see if per past contributions, plus the new one, add up to something legally significant. If so, you should get copyright papers for all per changes before you install the new change. If that is not so, you can install the small patch. Write @samp{(tiny change)} after the patch author's name, like this: @example 2002-11-04 Robert Fenk (tiny change) @end example @node Recording Contributors @section Recording Contributors @cindex recording contributors @strong{Keep correct records of which portions were written by whom.} This is very important. These records should say which files or parts of files were written by each person, and which files or parts of files were revised by each person. This should include installation scripts as well as manuals and documentation files---everything. These records don't need to be as detailed as a change log. They don't need to distinguish work done at different times, only different people. They don't need describe changes in more detail than which files or parts of a file were changed. And they don't need to say anything about the function or purpose of a file or change--the Register of Copyrights doesn't care what the text does, just who wrote or contributed to which parts. The list should also mention if certain files distributed in the same package are really a separate program. Only the contributions that are legally significant for copyright purposes (@pxref{Legally Significant}) need to be listed. Small contributions, bug reports, ideas, etc., can be omitted. For example, this would describe an early version of GAS: @display Dean Elsner first version of all files except gdb-lines.c and m68k.c. Jay Fenlason entire files gdb-lines.c and m68k.c, most of app.c, plus extensive changes in messages.c, input-file.c, write.c and revisions elsewhere. Note: GAS is distributed with the files obstack.c and obstack.h, but they are considered a separate package, not part of GAS proper. @end display @cindex @file{AUTHORS} file Please keep these records in a file named @file{AUTHORS} in the source directory for the program itself. You can use the change log as the basis for these records, if you wish. Just make sure to record the correct author for each change (the person who wrote the change, @emph{not} the person who installed it), and add @samp{(tiny change)} for those changes that are too trivial to matter for copyright purposes. Later on you can update the @file{AUTHORS} file from the change log. This can even be done automatically, if you are careful about the formatting of the change log entries. @node Copying from Other Packages @section Copying from Other Packages When you copy legally significant code from another free software package with a GPL-compatible license, you should look in the package's records to find out the authors of the part you are copying, and list them as the contributors of the code that you copied. If all you did was copy it, not write it, then for copyright purposes you are @emph{not} one of the contributors of @emph{this} code. Especially when code has been released into the public domain, authors sometimes fail to write a license statement in each file. In this case, please first be sure that all the authors of the code have disclaimed copyright interest. Then, when copying the new files into your project, add a brief note at the beginning of the files recording the authors, the public domain status, and anything else relevant. On the other hand, when merging some public domain code into an existing file covered by the GPL (or LGPL or other free software license), there is no reason to indicate the pieces which are public domain. The notice saying that the whole file is under the GPL (or other license) is legally sufficient. Using code that is released under a GPL-compatible free license, rather than being in the public domain, may require preserving copyright notices or other steps. Of course, you should do what is needed. If you are maintaining an FSF-copyrighted package, please verify we have papers for the code you are copying, @emph{before} copying it. If you are copying from another FSF-copyrighted package, then we presumably have papers for that package's own code, but you must check whether the code you are copying is part of an external library; if that is the case, we don't have papers for it, so you should not copy it. It can't hurt in any case to double-check with the developer of that package. When you are copying code for which we do not already have papers, you need to get papers for it. It may be difficult to get the papers if the code was not written as a contribution to your package, but that doesn't mean it is ok to do without them. If you cannot get papers for the code, you can only use it as an external library (@pxref{External Libraries}). @node Copyright Notices @section Copyright Notices @cindex copyright notices in program files You should maintain a proper copyright notice and a license notice in each nontrivial file in the package. (Any file more than ten lines long is nontrivial for this purpose.) This includes header files and interface definitions for building or running the program, documentation files, and any supporting files. If a file has been explicitly placed in the public domain, then instead of a copyright notice, it should have a notice saying explicitly that it is in the public domain. Even image files and sound files should contain copyright notices and license notices, if their format permits. Some formats do not have room for textual annotations; for these files, state the copyright and copying permissions in a @file{README} file in the same directory. Change log files should have a copyright notice and license notice at the end, since new material is added at the beginning but the end remains the end. When a file is automatically generated from some other file in the distribution, it is useful for the automatic procedure to copy the copyright notice and permission notice of the file it is generated from, if possible. Alternatively, put a notice at the beginning saying which file it is generated from. A copyright notice looks like this: @example Copyright (C) @var{year1}, @var{year2}, @var{year3} @var{copyright-holder} @end example The word @samp{Copyright} must always be in English, by international convention. The @var{copyright-holder} may be the Free Software Foundation, Inc., or someone else; you should know who is the copyright holder for your package. Replace the @samp{(C)} with a C-in-a-circle symbol if it is available. For example, use @samp{@@copyright@{@}} in a Texinfo file. However, stick with parenthesized @samp{C} unless you know that C-in-a-circle will work. For example, a program's standard @option{--version} message should use parenthesized @samp{C} by default, though message translations may use C-in-a-circle in locales where that symbol is known to work. Alternatively, the @samp{(C)} or C-in-a-circle can be omitted entirely; the word @samp{Copyright} suffices. To update the list of year numbers, add each year in which you have made nontrivial changes to the package. (Here we assume you're using a publicly accessible revision control server, so that every revision installed is also immediately and automatically published.) When you add the new year, it is not required to keep track of which files have seen significant changes in the new year and which have not. It is recommended and simpler to add the new year to all files in the package, and be done with it for the rest of the year. Don't delete old year numbers, though; they are significant since they indicate when older versions might theoretically go into the public domain, if the movie companies don't continue buying laws to further extend copyright. If you copy a file into the package from some other program, keep the copyright years that come with the file. Do not abbreviate the year list using a range; for instance, do not write @samp{1996--1998}; instead, write @samp{1996, 1997, 1998}. For files which are regularly copied from another project (such as @samp{gnulib}), leave the copyright notice as it is in the original. The copyright statement may be split across multiple lines, both in source files and in any generated output. This often happens for files with a long history, having many different years of publication. For an FSF-copyrighted package, if you have followed the procedures to obtain legal papers, each file should have just one copyright holder: the Free Software Foundation, Inc. You should edit the file's copyright notice to list that name and only that name. But if contributors are not all assigning their copyrights to a single copyright holder, it can easily happen that one file has several copyright holders. Each contributor of nontrivial text is a copyright holder. In that case, you should always include a copyright notice in the name of main copyright holder of the file. You can also include copyright notices for other copyright holders as well, and this is a good idea for those who have contributed a large amount and for those who specifically ask for notices in their names. (Sometimes the license on code that you copy in may require preserving certain copyright notices.) But you don't have to include a notice for everyone who contributed to the file (which would be rather inconvenient). Sometimes a program has an overall copyright notice that refers to the whole program. It might be in the @file{README} file, or it might be displayed when the program starts up. This copyright notice should mention the year of completion of the most recent major version; it can mention years of completion of previous major versions, but that is optional. @node License Notices @section License Notices @cindex license notices in program files Every nontrivial file needs a license notice as well as the copyright notice. (Without a license notice giving permission to copy and change the file, the file is non-free.) The package itself should contain a full copy of GPL in plain text (conventionally in a file named @file{COPYING}) and the GNU Free Documentation License (included within your documentation, so there is no need for a separate plain text version). If the package contains any files distributed under the Lesser GPL, it should contain a full copy of its plain text version also (conventionally in a file named @file{COPYING.LESSER}). If you have questions about license issues for your GNU package, please write @email{licensing@@gnu.org}. @menu * Source: Canonical License Sources. * Code: License Notices for Code. * Documentation: License Notices for Documentation. * Other: License Notices for Other Files. @end menu @node Canonical License Sources @subsection Canonical License Sources You can get the official versions of these files from several places. You can use whichever is the most convenient for you. @itemize @bullet @item @uref{http://www.gnu.org/licenses/}. @item The @code{gnulib} project on @code{savannah.gnu.org}, which you can access via anonymous Git or CVS. See @uref{http://savannah.gnu.org/projects/gnulib}. @end itemize The official Texinfo sources for the licenses are also available in those same places, so you can include them in your documentation. A GFDL-covered manual should include the GFDL in this way. @xref{GNU Sample Texts,,,texinfo,Texinfo}, for a full example in a Texinfo manual. @node License Notices for Code @subsection License Notices for Code Typically the license notice for program files (including build scripts, configure files and makefiles) should cite the GPL, like this: @quotation This file is part of GNU @var{program}. GNU @var{program} is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. GNU @var{program} is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see @url{http://www.gnu.org/licenses/}. @end quotation But in a small program which is just a few files, you can use this instead: @quotation This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see @url{http://www.gnu.org/licenses/}. @end quotation @node License Notices for Documentation @subsection License Notices for Documentation Documentation files should have license notices also. Manuals should use the GNU Free Documentation License. Following is an example of the license notice to use after the copyright line(s) using all the features of the GFDL. @smallexample Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being ``GNU General Public License'', with the Front-Cover Texts being ``A GNU Manual'', and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled ``GNU Free Documentation License''. (a) The FSF's Back-Cover Text is: ``You have the freedom to copy and modify this GNU manual. Buying copies from the FSF supports it in developing GNU and promoting software freedom.'' @end smallexample If the FSF does not publish this manual on paper, then omit the last sentence in (a) that talks about copies from GNU Press. If the FSF is not the copyright holder, then replace @samp{FSF} with the appropriate name. Please adjust the list of invariant sections as appropriate for your manual. If there are none, then say ``with no Invariant Sections''. If your manual is not published by the FSF, and under 400 pages, you can omit both cover texts. @xref{GNU Sample Texts,,,texinfo,Texinfo}, for a full example in a Texinfo manual, and see @url{http://www.gnu.org/licenses/fdl-howto.html} for more advice about how to use the GNU FDL. If the manual is over 400 pages, or if the FSF thinks it might be a good choice for publishing on paper, then please include the GNU GPL, as in the notice above. Please also include our standard invariant section which explains the importance of free documentation. Write to @email{assign@@gnu.org} to get a copy of this section. When you distribute several manuals together in one software package, their on-line forms can share a single copy of the GFDL (see section@tie{}6). However, the printed (@samp{.dvi}, @samp{.pdf}, @dots{}) forms should each contain a copy of the GFDL, unless they are set up to be printed and published only together. Therefore, it is usually simplest to include the GFDL in each manual. @node License Notices for Other Files @subsection License Notices for Other Files Small supporting files, short manuals (under 300 lines long) and rough documentation (@file{README} files, @file{INSTALL} files, etc.)@: can use a simple all-permissive license like this one: @smallexample Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. This file is offered as-is, without any warranty. @end smallexample Older versions of this license did not have the second sentence with the express warranty disclaimer. There is no urgent need to update existing files, but new files should use the new text. If your package distributes Autoconf macros that are intended to be used (hence distributed) by third-party packages under possibly incompatible licenses, you may also use the above all-permissive license for these macros. @node External Libraries @section External Libraries When maintaining an FSF-copyrighted GNU package, you may occasionally want to use a general-purpose free software module which offers a useful functionality, as a ``library'' facility (though the module is not always packaged technically as a library). In a case like this, it would be unreasonable to ask the author of that module to assign the copyright to the FSF. After all, person did not write it specifically as a contribution to your package, so it would be impertinent to ask per, out of the blue, ``Please give the FSF your copyright.'' So the thing to do in this case is to make your program use the module, but not consider it a part of your program. There are two reasonable methods of doing this: @enumerate @item Assume the module is already installed on the system, and use it when linking your program. This is only reasonable if the module really has the form of a library. @item Include the module in your package, putting the source in a separate subdirectory whose @file{README} file says, ``This is not part of the GNU FOO program, but is used with GNU FOO.'' Then set up your makefiles to build this module and link it into the executable. For this method, it is not necessary to treat the module as a library and make a @samp{.a} file from it. You can link with the @samp{.o} files directly in the usual manner. @end enumerate Both of these methods create an irregularity, and our lawyers have told us to minimize the amount of such irregularity. So consider using these methods only for general-purpose modules that were written for other programs and released separately for general use. For anything that was written as a contribution to your package, please get papers signed. @node Clean Ups @chapter Cleaning Up Changes @cindex contributions, accepting @cindex quality of changes suggested by others Don't feel obligated to include every change that someone asks you to include. You must judge which changes are improvements---partly based on what you think the users will like, and partly based on your own judgment of what is better. If you think a change is not good, you should reject it. If someone sends you changes which are useful, but written in an ugly way or hard to understand and maintain in the future, don't hesitate to ask per to clean up their changes before you merge them. Since the amount of work we can do is limited, the more we convince others to help us work efficiently, the faster GNU will advance. If the contributor will not or can not make the changes clean enough, then it is legitimate to say ``I can't install this in its present form; I can only do so if you clean it up.'' Invite per to distribute per changes another way, or to find other people to make them clean enough for you to install and maintain. The only reason to do these cleanups yourself is if (1) it is easy, less work than telling the author what to clean up, or (2) the change is an important one, important enough to be worth the work of cleaning it up. The GNU Coding Standards are a good thing to send people when you ask them to clean up changes (@pxref{Top, , Contents, standards, GNU Coding Standards}). The Emacs Lisp manual contains an appendix that gives coding standards for Emacs Lisp programs; it is good to urge Lisp authors to read it (@pxref{Tips, , Tips and Conventions, elisp, The GNU Emacs Lisp Reference Manual}). @node Platforms @chapter Platforms to Support Most GNU packages run on a wide range of platforms. These platforms are not equally important. The most important platforms for a GNU package to support are GNU and GNU/Linux. Developing the GNU operating system is the whole point of the GNU Project; a GNU package exists to make the whole GNU system more powerful. So please keep that goal in mind and let it shape your work. For instance, every new feature you add should work on GNU, and GNU/Linux if possible too. If a new feature only runs on GNU and GNU/Linux, it could still be acceptable. However, a feature that runs only on other systems and not on GNU or GNU/Linux makes no sense in a GNU package. You will naturally want to keep the program running on all the platforms it supports. But you personally will not have access to most of these platforms--so how should you do it? Don't worry about trying to get access to all of these platforms. Even if you did have access to all the platforms, it would be inefficient for you to test the program on each platform yourself. Instead, you should test the program on a few platforms, including GNU or GNU/Linux, and let the users test it on the other platforms. You can do this through a pretest phase before the real release; when there is no reason to expect problems, in a package that is mostly portable, you can just make a release and let the users tell you if anything unportable was introduced. It is important to test the program personally on GNU or GNU/Linux, because these are the most important platforms for a GNU package. If you don't have access to one of these platforms, please ask @email{maintainers@@gnu.org} to help you out. Supporting other platforms is optional---we do it when that seems like a good idea, but we don't consider it obligatory. If the users don't take care of a certain platform, you may have to desupport it unless and until users come forward to help. Conversely, if a user offers changes to support an additional platform, you will probably want to install them, but you don't have to. If you feel the changes are complex and ugly, if you think that they will increase the burden of future maintenance, you can and should reject them. This includes both free or mainly-free platforms such as OpenBSD, FreeBSD, and NetBSD, and non-free platforms such as Windows. @node Mail @chapter Dealing With Mail @cindex bug reports @cindex email, for receiving bug reports @cindex mailing list for bug reports Once a program is in use, you will get bug reports for it. Most GNU programs have their own special lists for sending bug reports. The advertised bug-reporting email address should always be @samp{bug-@var{program}@@gnu.org}, to help show users that the program is a GNU package, but it is ok to set up that list to forward to another site for further forwarding. The package distribution should state the name of the bug-reporting list in a prominent place, and ask users to help us by reporting bugs there. We also have a catch-all list, @email{bug-gnu-utils@@gnu.org}, which is used for all GNU programs that don't have their own specific lists. But nowadays we want to give each program its own bug-reporting list and move away from using @email{bug-gnu-utils}. If you wish, you can also have mailing lists such as @samp{info-@var{program}} for announcements (@pxref{Announcements}), @samp{help-@var{program}} for general help and discussion (see below), or any others you find useful. By far the easiest way to create mailing lists is through @code{savannah.gnu.org}. Once you register your program, you can do this yourself through the `Mailing Lists' menu, without needing intervention by anyone else. Furthermore, lists created through Savannah will have a reasonable default configuration for antispam purposes (see below). If you are the maintainer of a GNU package, you should have an account on the GNU servers; contact @url{http://www.gnu.org/software/README.accounts.html} if you don't have one. (You can also ask for accounts for people who help you a large amount in working on the package.) With this account, you can edit @file{/com/mailer/aliases} to create a new unmanaged list or add yourself to an existing unmanaged list. A comment near the beginning of that file explains how to create a Mailman-managed mailing list. But if you don't want to learn how to do those things, you can alternatively ask @email{alias-file@@gnu.org} to add you to the bug-reporting list for your program. To set up a new list, contact @email{new-mailing-list@@gnu.org}. You can subscribe to a list managed by Mailman by sending mail to the corresponding @samp{-request} address. You should moderate postings from non-subscribed addresses on your mailing lists, to prevent propagation of unwanted messages (``spam'') to subscribers and to the list archives. For lists controlled by Mailman, you can do this by setting @code{Privacy Options - Sender Filter - generic_nonmember_action} to @code{Hold}, and then periodically (daily is best) reviewing the held messages, accepting the real ones and discarding the junk. @cindex responding to bug reports When you receive bug reports, keep in mind that bug reports are crucial for your work. If you don't know about problems, you cannot fix them. So always thank each person who sends a bug report. You don't have an obligation to give more response than that, though. The main purpose of bug reports is to help you contribute to the community by improving the next version of the program. Many of the people who report bugs don't realize this---they think that the point is for you to help them individually. Some will ask you to focus on that @emph{instead of} on making the program better. If you comply with their wishes, you will have been distracted from the job of maintaining the program. For example, people sometimes report a bug in a vague (and therefore useless) way, and when you ask for more information, they say, ``I just wanted to see if you already knew the solution'' (in which case the bug report would do nothing to help improve the program). When this happens, you should explain to them the real purpose of bug reports. (A canned explanation will make this more efficient.) When people ask you to put your time into helping them use the program, it may seem ``helpful'' to do what they ask. But it is much @emph{less} helpful than improving the program, which is the maintainer's real job. By all means help individual users when you feel like it, if you feel you have the time available. But be careful to limit the amount of time you spend doing this---don't let it eat away the time you need to maintain the program! Know how to say no; when you are pressed for time, just ``thanks for the bug report---I will fix it'' is enough response. Some GNU packages, such as Emacs and GCC, come with advice about how to make bug reports useful. If you want to copy and adapt that, it could be a very useful thing to do. @node Old Versions @chapter Recording Old Versions @cindex version control It is very important to keep backup files of all source files of GNU. You can do this using a source control system (such as RCS, CVS, Git, @dots{}) if you like. The easiest way to use RCS or CVS is via the Version Control library in Emacs (@pxref{VC Concepts,, Concepts of Version Control, emacs, The GNU Emacs Manual}). The history of previous revisions and log entries is very important for future maintainers of the package, so even if you do not make it publicly accessible, be careful not to put anything in the repository or change log that you would not want to hand over to another maintainer some day. @cindex @code{savannah-hackers@@gnu.org} The GNU Project provides a server that GNU software packages can use for source control and other package needs: @code{savannah.gnu.org}. You don't have to use this repository, but if you plan to allow public read-only access to your development sources, it is convenient for people to be able to find various GNU packages in a central place. Savannah is managed by @email{savannah-hackers@@gnu.org}. All GNU maintainers are strongly encouraged to take advantage of Savannah, as sharing such a central point can serve to foster a sense of community among GNU developers and help in keeping up with project management. @cindex @code{savannah-announce@@gnu.org} mailing list If you do use Savannah, it is a good idea to subscribe to the @email{savannah-announce@@gnu.org} mailing list (@url{http://lists.gnu.org/mailman/listinfo/savannah-announce}). This is a very low-volume list to keep Savannah users informed of system upgrades, problems, and the like. @node Distributions @chapter Distributions It is important to follow the GNU conventions when making GNU software distributions. @menu * Distribution tar Files:: * Distribution Patches:: * Distribution on ftp.gnu.org:: * Test Releases:: * Automated FTP Uploads:: * Announcements:: @end menu @node Distribution tar Files @section Distribution tar Files @cindex distribution, tar files The tar file for version @var{m}.@var{n} of program @code{foo} should be named @file{foo-@var{m}.@var{n}.tar}. It should unpack into a subdirectory named @file{foo-@var{m}.@var{n}}. Tar files should not unpack into files in the current directory, because this is inconvenient if the user happens to unpack into a directory with other files in it. Here is how the @file{Makefile} for Bison creates the tar file. This method is good for other programs. @example dist: bison.info echo bison-`sed -e '/version_string/!d' \ -e 's/[^0-9.]*\([0-9.]*\).*/\1/' -e q version.c` > .fname -rm -rf `cat .fname` mkdir `cat .fname` dst=`cat .fname`; for f in $(DISTFILES); do \ ln $(srcdir)/$$f $$dst/$$f || @{ echo copying $$f; \ cp -p $(srcdir)/$$f $$dst/$$f ; @} \ done tar --gzip -chf `cat .fname`.tar.gz `cat .fname` -rm -rf `cat .fname` .fname @end example Source files that are symbolic links to other file systems cannot be installed in the temporary directory using @code{ln}, so use @code{cp} if @code{ln} fails. @pindex automake Using Automake is a good way to take care of writing the @code{dist} target. @node Distribution Patches @section Distribution Patches @cindex patches, against previous releases If the program is large, it is useful to make a set of diffs for each release, against the previous important release. At the front of the set of diffs, put a short explanation of which version this is for and which previous version it is relative to. Also explain what else people need to do to update the sources properly (for example, delete or rename certain files before installing the diffs). The purpose of having diffs is that they are small. To keep them small, exclude files that the user can easily update. For example, exclude info files, DVI files, tags tables, output files of Bison or Flex. In Emacs diffs, we exclude compiled Lisp files, leaving it up to the installer to recompile the patched sources. When you make the diffs, each version should be in a directory suitably named---for example, @file{gcc-2.3.2} and @file{gcc-2.3.3}. This way, it will be very clear from the diffs themselves which version is which. @pindex diff @pindex patch @cindex time stamp in diffs If you use GNU @code{diff} to make the patch, use the options @samp{-rc2P}. That will put any new files into the output as ``entirely different.'' Also, the patch's context diff headers should have dates and times in Universal Time using traditional Unix format, so that patch recipients can use GNU @code{patch}'s @samp{-Z} option. For example, you could use the following Bourne shell command to create the patch: @example LC_ALL=C TZ=UTC0 diff -rc2P gcc-2.3.2 gcc-2.3.3 | \ gzip -9 >gcc-2.3.2-2.3.3.patch.gz @end example If the distribution has subdirectories in it, then the diffs probably include some files in the subdirectories. To help users install such patches reliably, give them precise directions for how to run patch. For example, say this: @display To apply these patches, cd to the main directory of the program and then use `patch -p1'. `-p1' avoids guesswork in choosing which subdirectory to find each file in. @end display It's wise to test your patch by applying it to a copy of the old version, and checking that the result exactly matches the new version. @node Distribution on ftp.gnu.org @section Distribution on @code{ftp.gnu.org} @cindex GNU ftp site @cindex @code{ftp.gnu.org}, the GNU ftp site GNU packages are distributed through directory @file{/gnu} on @code{ftp.gnu.org}. Each package should have a subdirectory named after the package, and all the distribution files for the package should go in that subdirectory. @c If you have an interest in seeing the monthly download logs from the FTP @c site at @code{ftp.gnu.org} for your program, that is something that @c @email{ftp-upload@@gnu.org} can set up for you. Please contact them if @c you are interested. @xref{Automated FTP Uploads}, for procedural details of putting new versions on @code{ftp.gnu.org}. @node Test Releases @section Test Releases @cindex test releases @cindex beta releases @cindex pretest releases @cindex @code{alpha.gnu.org}, ftp site for test releases When you release a greatly changed new major version of a program, you might want to do so as a pretest. This means that you make a tar file, but send it only to a group of volunteers that you have recruited. (Use a suitable GNU mailing list/newsgroup to recruit them.) We normally use the FTP server @code{alpha.gnu.org} for pretests and prerelease versions. @xref{Automated FTP Uploads}, for procedural details of putting new versions on @code{alpha.gnu.org}. Once a program gets to be widely used and people expect it to work solidly, it is a good idea to do pretest releases before each ``real'' release. There are two ways of handling version numbers for pretest versions. One method is to treat them as versions preceding the release you are going to make. In this method, if you are about to release version 4.6 but you want to do a pretest first, call it 4.5.90. If you need a second pretest, call it 4.5.91, and so on. If you are really unlucky and ten pretests are not enough, after 4.5.99 you could advance to 4.5.990 and so on. (You could also use 4.5.100, but 990 has the advantage of sorting in the right order.) The other method is to attach a date to the release number that is coming. For a pretest for version 4.6, made on Dec 10, 2002, this would be 4.6.20021210. A second pretest made the same day could be 4.6.20021210.1. For development snapshots that are not formal pretests, using just the date without the version numbers is ok too. One thing that you should never do is to release a pretest with the same version number as the planned real release. Many people will look only at the version number (in the tar file name, in the directory name that it unpacks into, or wherever they can find it) to determine whether a tar file is the latest version. People might look at the test release in this way and mistake it for the real release. Therefore, always change the number when you release changed code. @node Automated FTP Uploads @section Automated FTP Uploads @cindex ftp uploads, automated In order to upload new releases to @code{ftp.gnu.org} or @code{alpha.gnu.org}, you first need to register the necessary information. Then, you can perform uploads yourself, with no intervention needed by the system administrators. The general idea is that releases should be crytographically signed before they are made publicly available. @menu * Automated Upload Registration:: * Automated Upload Procedure:: * FTP Upload Directive File - v1.1:: * FTP Upload Directive File - v1.0:: @end menu @node Automated Upload Registration @subsection Automated Upload Registration @cindex registration for uploads @cindex uploads, registration for Here is how to register your information so you can perform uploads for your GNU package: @enumerate @item Create an account for yourself at @url{http://savannah.gnu.org}, if you don't already have one. By the way, this is also needed to maintain the web pages at @url{www.gnu.org} for your project (@pxref{Web Pages}). @item In the @samp{My Account Conf} page on @code{savannah}, upload the GPG key you will use to sign your packages. You can create a key with the command @code{gpg --gen-key}. It is good to also send your key to the GPG public key server: @code{gpg --keyserver keys.gnupg.net --send-keys @var{keyid}}, where @var{keyid} is the eight hex digits reported by @code{gpg --list-public-keys} on the @code{pub} line before the date. For full information about GPG, see @url{http://www.gnu.org/software/gpg}) @item Compose a message with the following items in some @var{msgfile}. Then GPG-sign it by running @code{gpg --clearsign @var{msgfile}}, and finally email the resulting @file{@var{msgfile}.asc}), to @email{ftp-upload@@gnu.org}. @enumerate @item Name of package(s) that you are the maintainer for, and your preferred email address. @item An ASCII armored copy of your GnuPG key, as an attachment. (@samp{gpg --export -a @var{your_key_id} >mykey.asc} should give you this.) @item A list of names and preferred email addresses of other individuals you authorize to make releases for which packages, if any (in the case that you don't make all releases yourself). @item ASCII armored copies of GnuPG keys for any individuals listed in (3). @end enumerate @end enumerate The administrators will acknowledge your message when they have added the proper GPG keys as authorized to upload files for the corresponding packages. The upload system will email receipts to the given email addresses when an upload is made, either successfully or unsuccessfully. @node Automated Upload Procedure @subsection Automated Upload Procedure @cindex uploads Once you have registered your information as described in the previous section, you will be able to do ftp uploads for yourself using the following procedure. For each upload destined for @code{ftp.gnu.org} or @code{alpha.gnu.org}, three files (a @dfn{triplet}) need to be uploaded via ftp to the host @code{ftp-upload.gnu.org}. @enumerate @item The file to be distributed; for example, @file{foo.tar.gz}. @item Detached GPG binary signature file for (1); for example, @file{foo.tar.gz.sig}. Make this with @samp{gpg -b foo.tar.gz}. @item A clearsigned @dfn{directive file}; for example, @file{foo.tar.gz.directive.asc}. Make this by preparing the plain text file @file{foo.tar.gz.directive} and then run @samp{gpg --clearsign foo.tar.gz.directive}. @xref{FTP Upload Directive File - v1.1}, for the contents of the directive file. @end enumerate The names of the files are important. The signature file must have the same name as the file to be distributed, with an additional @file{.sig} extension. The directive file must have the same name as the file to be distributed, with an additional @file{.directive.asc} extension. If you do not follow this naming convention, the upload @emph{will not be processed}. Since v1.1 of the upload script, it is also possible to upload a clearsigned directive file on its own (no accompanying @file{.sig} or any other file) to perform certain operations on the server. @xref{FTP Upload Directive File - v1.1}, for more information. Upload the file(s) via anonymous ftp to @code{ftp-upload.gnu.org}. If the upload is destined for @code{ftp.gnu.org}, place the file(s) in the @file{/incoming/ftp} directory. If the upload is destined for @code{alpha.gnu.org}, place the file(s) in the @file{/incoming/alpha} directory. Uploads are processed every five minutes. Uploads that are in progress while the upload processing script is running are handled properly, so do not worry about the timing of your upload. Uploaded files that belong to an incomplete triplet are deleted automatically after 24 hours. Your designated upload email addresses (@pxref{Automated Upload Registration}) are sent a message if there are any problems processing an upload for your package. You also receive a message when your upload has been successfully processed. One automated way to create and transfer the necessary files is to use the @code{gnupload} script, which is available from the @file{build-aux/} directory of the @code{gnulib} project at @url{http://savannah.gnu.org/projects/gnulib}. @code{gnupload} can also remove uploaded files. Run @code{gnupload --help} for a description and examples. @code{gnupload} uses the @code{ncftpput} program to do the actual transfers; if you don't happen to have the @code{ncftp} package installed, the @code{ncftpput-ftp} script in the @file{build-aux/} directory of @code{gnulib} serves as a replacement which uses plain command line @code{ftp}. If you have difficulties with an upload, email @email{ftp-upload@@gnu.org}. @node FTP Upload Directive File - v1.1 @subsection FTP Upload Directive File - v1.1 The directive file name must end in @file{directive.asc}. When part of a triplet, the directive file must always contain the directives @code{version}, @code{directory} and @code{filename}, as described. In addition, a 'comment' directive is allowed. The @code{version} directive must always have the value @samp{1.1}. The @code{directory} directive specifies the final destination directory where the uploaded file and its @file{.sig} companion are to be placed. The @code{filename} directive must contain the name of the file to be distributed (item@tie{}(1) above). For example, as part of an uploaded triplet, a @file{foo.tar.gz.directive.asc} file might contain these lines (before being gpg clearsigned): @example version: 1.1 directory: bar/v1 filename: foo.tar.gz comment: hello world! @end example This directory line indicates that @file{foo.tar.gz} and @file{foo.tar.gz.sig} are part of package @code{bar}. If you uploaded this triplet to @file{/incoming/ftp} and the system positively authenticates the signatures, the files @file{foo.tar.gz} and @file{foo.tar.gz.sig} will be placed in the directory @file{gnu/bar/v1} of the @code{ftp.gnu.org} site. The directive file can be used to create currently non-existent directory trees, as long as they are under the package directory for your package (in the example above, that is @code{bar}). If you upload a file that already exists in the FTP directory, the original will simply be archived and replaced with the new upload. @subheading Standalone directives When uploaded by itself, the directive file must contain one or more of the directives @code{symlink}, @code{rmsymlink} or @code{archive}, in addition to the obligatory @code{directory} and @code{version} directives. A @code{filename} directive is not allowed, and a @code{comment} directive remains optional. If you use more than one directive, the directives are executed in the sequence they are specified in. If a directive results in an error, further execution of the upload is aborted. Removing a symbolic link (with @code{rmsymlink}) which does not exist results in an error. However, attempting to create a symbolic link that already exists (with @code{symlink}) is not an error. In this case @code{symlink} behaves like the command @command{ln -s -f}: any existing symlink is removed before creating the link. (But an existing regular file or directory is not removed.) Here are a few examples. The first removes a symlink: @example version: 1.1 directory: bar/v1 rmsymlink: foo-latest.tgz comment: remove a symlink @end example @noindent Archive an old file, taking it offline: @example version: 1.1 directory: bar/v1 archive: foo-1.1.tar.gz comment: archive an old file; it will not be available through FTP anymore @end example @noindent Archive an old directory (with all contents), taking it offline: @example version: 1.1 directory: bar/v1 archive: foo comment: archive an old directory; it will not be available through FTP anymore @end example @noindent Create a new symlink: @example version: 1.1 directory: bar/v1 symlink: foo-1.2.tar.gz foo-latest.tgz comment: create a new symlink @end example @noindent Do everything at once: @example version: 1.1 directory: bar/v1 rmsymlink: foo-latest.tgz symlink: foo-1.2.tar.gz foo-latest.tgz archive: foo-1.1.tar.gz comment: now do everything at once @end example @node FTP Upload Directive File - v1.0 @subsection FTP Upload Directive File - v1.0 @dfn{As of June 2006, the upload script is running in compatibility mode, allowing uploads with either version@tie{}1.1 or version@tie{}1.0 of the directive file syntax. Support for v1.0 uploads will be phased out by the end of 2006, so please upgrade to@tie{}v1.1.} The directive file should contain one line, excluding the clearsigned data GPG that inserts, which specifies the final destination directory where items (1) and (2) are to be placed. For example, the @file{foo.tar.gz.directive.asc} file might contain the single line: @example directory: bar/v1 @end example This directory line indicates that @file{foo.tar.gz} and @file{foo.tar.gz.sig} are part of package @code{bar}. If you were to upload the triplet to @file{/incoming/ftp}, and the system can positively authenticate the signatures, then the files @file{foo.tar.gz} and @file{foo.tar.gz.sig} will be placed in the directory @file{gnu/bar/v1} of the @code{ftp.gnu.org} site. The directive file can be used to create currently non-existent directory trees, as long as they are under the package directory for your package (in the example above, that is @code{bar}). @node Announcements @section Announcing Releases @cindex announcements @cindex @code{info-gnu} mailing list When you have a new release, please make an announcement. For official new releases, including those made just to fix bugs, we strongly recommend using the (moderated) general GNU announcements list, @email{info-gnu@@gnu.org}. Doing so makes it easier for users and developers to find the latest GNU releases. On the other hand, please do not announce test releases on @code{info-gnu} unless it's a highly unusual situation. @cindex @url{http://planet.gnu.org} @cindex Savannah, news area Please also post release announcements in the news section of your Savannah project site. It is fine to also write news entries for test releases and any other newsworthy events. The news feeds from all GNU projects at savannah are aggregated at @url{http://planet.gnu.org} (GNU Planet). You can also post items directly, or arrange for feeds from other locations; see contact information on the GNU Planet web page. @cindex announcement mailing list, project-specific You can maintain your own mailing list (typically @email{info-@var{program}@@gnu.org}) for announcements as well if you like. For your own list, of course you decide as you see fit what events are worth announcing. (@xref{Mail}, for more suggestions on handling mail for your package.) @cindex contents of announcements When writing an announcement, please include the following: @itemize @bullet @item A very brief description (a few sentences at most) of the general purpose of your package. @item Your package's web page (normally @indicateurl{http://www.gnu.org/software/@var{package}/}). @item Your package's download location (normally @indicateurl{http://ftp.gnu.org/gnu/@var{package}/}). It is also useful to mention the FTP mirror list at @url{http://www.gnu.org/order/ftp.html}, and that @url{http://ftpmirror.gnu.org/@var{package/}} will automatically redirect to a nearby mirror. @item The NEWS (@pxref{NEWS File,,, standards, GNU Coding Standards}) for the present release. @end itemize @node Web Pages @chapter Web Pages @cindex web pages Please write web pages about your package for installation on @code{www.gnu.org}. They should follow our usual standards for web pages (see @url{http://www.gnu.org/server/fsf-html-style-sheet.html}). The overall goals are to support a wide variety of browsers, to focus on information rather than flashy eye candy, and to keep the site simple and uniform. Some GNU packages have just simple web pages, but the more information you provide, the better. So please write as much as you usefully can, and put all of it on @code{www.gnu.org}. However, pages that access databases (including mail logs and bug tracking) are an exception; set them up on whatever site is convenient for you, and make the pages on @code{www.gnu.org} link to that site. @menu * Hosting for Web Pages:: * Freedom for Web Pages:: * Manuals on Web Pages:: * CVS Keywords in Web Pages:: @end menu @node Hosting for Web Pages @section Hosting for Web Pages The best way to maintain the web pages for your project is to register the project on @code{savannah.gnu.org}. Then you can edit the pages using CVS, using the separate ``web repository'' available on Savannah, which corresponds to @indicateurl{http://www.gnu.org/software/@var{package}/}. You can keep your source files there too (using any of a variety of version control systems), but you can use @code{savannah.gnu.org} only for your gnu.org web pages if you wish; simply register a ``web-only'' project. If you don't want to use that method, please talk with @email{webmasters@@gnu.org} about other possible methods. For instance, you can mail them pages to install, if necessary. But that is more work for them, so please use Savannah if you can. If you use Savannah, you can use a special @file{.symlinks} file in order to create symbolic links, which are not supported in CVS. For details, see @url{http://www.gnu.org/server/standards/README.webmastering.html#symlinks}. @node Freedom for Web Pages @section Freedom for Web Pages If you use a site other than @code{www.gnu.org}, please make sure that the site runs on free software alone. (It is ok if the site uses unreleased custom software, since that is free in a trivial sense: there's only one user and it has the four freedoms.) If the web site for a GNU package runs on non-free software, the public will see this, and it will have the effect of granting legitimacy to the non-free program. If you use multiple sites, they should all follow that criterion. Please don't link to a site that is about your package, which the public might perceive as connected with it and reflecting the position of its developers, unless it follows that criterion. Historically, web pages for GNU packages did not include GIF images, because of patent problems (@pxref{Ethical and Philosophical Consideration}). Although the GIF patents expired in 2006, using GIF images is still not recommended, as the PNG and JPEG formats are generally superior. See @url{http://www.gnu.org/philosophy/gif.html}. @node Manuals on Web Pages @section Manuals on Web Pages The web pages for the package should include its manuals, in HTML, DVI, Info, PostScript, PDF, plain ASCII, and Texinfo format (source). All of these can be generated automatically from the Texinfo source using Makeinfo and other programs. When there is only one manual, put it in a subdirectory called @file{manual}; the file @file{manual/index.html} should have a link to the manual in each of its forms. If the package has more than one manual, put each one in a subdirectory of @file{manual}, set up @file{index.html} in each subdirectory to link to that manual in all its forms, and make @file{manual/index.html} link to each manual through its subdirectory. See the section below for details on a script to make the job of creating all these different formats and index pages easier. We would like to include links to all GNU manuals on the page @url{http://www.gnu.org/manual}, so if yours isn't listed, please send mail to @code{webmasters@@gnu.org} telling them the name of your package and asking them to edit @url{http://www.gnu.org/manual}, and they will do so based on the contents of your @file{manual} directory. @menu * Invoking gendocs.sh:: @end menu @node Invoking gendocs.sh @subsection Invoking @command{gendocs.sh} @pindex gendocs.sh @cindex generating documentation output The script @command{gendocs.sh} eases the task of generating the Texinfo documentation output for your web pages section above. It has a companion template file, used as the basis for the HTML index pages. Both are available from the Texinfo CVS sources: @smallformat @uref{http://savannah.gnu.org/cgi-bin/viewcvs/texinfo/texinfo/util/gendocs.sh} @uref{http://savannah.gnu.org/cgi-bin/viewcvs/texinfo/texinfo/util/gendocs_template} @end smallformat There is also a minimalistic template, available from: @smallformat @uref{http://savannah.gnu.org/cgi-bin/viewcvs/texinfo/texinfo/util/gendocs_template_min} @end smallformat Invoke the script like this, in the directory containing the Texinfo source: @smallexample gendocs.sh --email @var{yourbuglist} @var{yourmanual} "GNU @var{yourmanual} manual" @end smallexample @noindent where @var{yourmanual} is the short name for your package and @var{yourbuglist} is the email address for bug reports (typically @code{bug-@var{package}@@gnu.org}). The script processes the file @file{@var{yourmanual}.texinfo} (or @file{.texi} or @file{.txi}). For example: @smallexample cd .../emacs/man # download gendocs.sh and gendocs_template gendocs.sh --email bug-gnu-emacs@@gnu.org emacs "GNU Emacs manual" @end smallexample @command{gendocs.sh} creates a subdirectory @file{manual/} containing the manual generated in all the standard output formats: Info, HTML, DVI, and so on, as well as the Texinfo source. You then need to move all those files, retaining the subdirectories, into the web pages for your package. You can specify the option @option{-o @var{outdir}} to override the name @file{manual}. Any previous contents of @var{outdir} will be deleted. The second argument, with the description, is included as part of the HTML @code{} of the overall @file{manual/index.html} file. It should include the name of the package being documented, as shown. @file{manual/index.html} is created by substitution from the file @file{gendocs_template}. (Feel free to modify the generic template for your own purposes.) If you have several manuals, you'll need to run this script several times with different arguments, specifying a different output directory with @option{-o} each time, and moving all the output to your web page. Then write (by hand) an overall index.html with links to them all. For example: @smallexample cd .../texinfo/doc gendocs.sh --email bug-texinfo@@gnu.org -o texinfo texinfo "GNU Texinfo manual" gendocs.sh --email bug-texinfo@@gnu.org -o info info "GNU Info manual" gendocs.sh --email bug-texinfo@@gnu.org -o info-stnd info-stnd "GNU info-stnd manual" @end smallexample By default, the script uses @command{makeinfo} for generating @acronym{HTML} output. If you prefer to use @command{texi2html}, use the @option{--texi2html} command line option, e.g.: @smallexample gendocs --texi2html -o texinfo texinfo "GNU Texinfo manual" @end smallexample The template files will automatically produce entries for additional HTML output generated by @command{texi2html} (i.e., split by sections and chapters). You can set the environment variables @env{MAKEINFO}, @env{TEXI2DVI}, @env{TEXI2HTML} and @env{DVIPS} to control the programs that get executed, and @env{GENDOCS_TEMPLATE_DIR} to control where the @file{gendocs_template} file is found. As usual, run @samp{gendocs.sh --help} for a description of all the options, environment variables, and more information. Please email bug reports, enhancement requests, or other correspondence to @email{bug-texinfo@@gnu.org}. @node CVS Keywords in Web Pages @section CVS Keywords in Web Pages @cindex CVS keywords in web pages @cindex RCS keywords in web pages @cindex $ keywords in web pages @cindex web pages, and CVS keywords Since @code{www.gnu.org} works through CVS, CVS keywords in your manual, such as @code{@w{$}Log$}, need special treatment (even if you don't happen to maintain your manual in CVS). If these keywords end up in the generated output as literal strings, they will be expanded. The most robust way to handle this is to turn off keyword expansion for such generated files. For existing files, this is done with: @example cvs admin -ko @var{file1} @var{file2} ... @end example @noindent For new files: @example cvs add -ko @var{file1} @var{file2} ... @end example @xref{Keyword substitution,,,cvs,Version Management with CVS}. In Texinfo source, the recommended way to literally specify a ``dollar'' keyword is: @example @@w@{$@}Log$ @end example The @code{@@w} prevents keyword expansion in the Texinfo source itself. Also, @code{makeinfo} notices the @code{@@w} and generates output avoiding the literal keyword string. @node Ethical and Philosophical Consideration @chapter Ethical and Philosophical Consideration @cindex ethics @cindex philosophy The GNU project takes a strong stand for software freedom. Many times, this means you'll need to avoid certain technologies when their use would conflict with our long-term goals. Software patents threaten the advancement of free software and freedom to program. There are so many software patents in the US that any large program probably implements hundreds of patented techniques, unknown to the program's developers. It would be futile and self-defeating to try to find and avoid all these patents. But there are some patents which we know are likely to be used to threaten free software, so we make an effort to avoid the patented techniques. If you are concerned about the danger of a patent and would like advice, write to @email{maintainers@@gnu.org}, and we will try to help you get advice from a lawyer. Sometimes the GNU project takes a strong stand against a particular patented technology in order to encourage society to reject it. For example, the MP3 audio format is covered by a software patent in the USA and some other countries. A patent holder has threatened lawsuits against the developers of free programs (these are not GNU programs) to produce and play MP3, and some GNU/Linux distributors are afraid to include them. Development of the programs continues, but we campaign for the rejection of MP3 format in favor of Ogg Vorbis format. A GNU package should not recommend use of any non-free program, nor should it require a non-free program (such as a non-free compiler or IDE) to build. Thus, a GNU package cannot be written in a programming language that does not have a free software implementation. Now that GNU/Linux systems are widely available, all GNU packages should provide full functionality on a 100% free GNU/Linux system, and should not require any non-free software to build or function. The GNU Coding Standards say a lot more about this issue. A GNU package should not refer the user to any non-free documentation for free software. The need for free documentation to come with free software is now a major focus of the GNU project; to show that we are serious about the need for free documentation, we must not contradict our position by recommending use of documentation that isn't free. Finally, new issues concerning the ethics of software freedom come up frequently. We ask that GNU maintainers, at least on matters that pertain specifically to their package, stand with the rest of the GNU project when such issues come up. @node Terminology @chapter Terminology Issues @cindex terminology This chapter explains a couple of issues of terminology which are important for correcting two widespread and important misunderstandings about GNU. @menu * Free Software and Open Source:: * GNU and Linux:: @end menu @node Free Software and Open Source @section Free Software and Open Source @cindex free software @cindex open source @cindex movements, Free Software and Open Source The terms ``free software'' and ``open source'' are the slogans of two different movements which differ in their basic philosophy. The Free Software Movement is idealistic, and raises issues of freedom, ethics, principle and what makes for a good society. The Open Source Movement, founded in 1998, studiously avoids such questions. For more explanation, see @url{http://www.gnu.org/philosophy/open-source-misses-the-point.html}. The GNU Project is aligned with the Free Software Movement. This doesn't mean that all GNU contributors and maintainers have to agree; your views on these issues are up to you, and you're entitled to express them when speaking for yourself. However, due to the much greater publicity that the Open Source Movement receives, the GNU Project needs to overcome a widespread mistaken impression that GNU is @emph{and always was} an activity of the Open Source Movement. For this reason, please use the term ``free software'', not ``open source'', in GNU software releases, GNU documentation, and announcements and articles that you publish in your role as the maintainer of a GNU package. A reference to the URL given above, to explain the difference, is a useful thing to include as well. @node GNU and Linux @section GNU and Linux @cindex Linux @cindex GNU/Linux The GNU Project was formed to develop a free Unix-like operating system, GNU. The existence of this system is our major accomplishment. However, the widely used version of the GNU system, in which Linux is used as the kernel, is often called simply ``Linux''. As a result, most users don't know about the GNU Project's major accomplishment---or more precisely, they know about it, but don't realize it is the GNU Project's accomplishment and reason for existence. Even people who believe they know the real history often believe that the goal of GNU was to develop ``tools'' or ``utilities.'' To correct this confusion, we have made a years-long effort to distinguish between Linux, the kernel that Linus Torvalds wrote, and GNU/Linux, the operating system that is the combination of GNU and Linux. The resulting increased awareness of what the GNU Project has already done helps every activity of the GNU Project recruit more support and contributors. Please make this distinction consistently in GNU software releases, GNU documentation, and announcements and articles that you publish in your role as the maintainer of a GNU package. If you want to explain the terminology and its reasons, you can refer to the URL @url{http://www.gnu.org/gnu/linux-and-gnu.html}. To contrast the GNU system properly with respect to GNU/Linux, you can call it ``GNU/Hurd'' or ``the GNU/Hurd system.'' However, when that contrast is not specifically the focus, please call it just ``GNU'' or ``the GNU system.'' When referring to the collection of servers that is the higher level of the GNU kernel, please call it ``the Hurd'' or ``the GNU Hurd.'' Note that this uses a space, not a slash. @node Hosting @chapter Hosting @cindex CVS repository @cindex repository @cindex source repository @cindex version control system @cindex FTP site @cindex hosting We recommend using @code{savannah.gnu.org} for the source code repository for your package, and, even more so, using @code{ftp.gnu.org} as the standard distribution site. Doing so makes it easier for developers and users to find the latest GNU releases. @xref{Old Versions}, for more information about Savannah. However, it is ok to use other machines if you wish. If you use a company's machine to hold the repository for your program, or as its ftp site, please put this statement in a prominent place on the site, so as to prevent people from getting the wrong idea about the relationship between the package and the company: @smallexample The programs <list of them> hosted here are free software packages of the GNU Project, not products of <company name>. We call them "free software" because you are free to copy and redistribute them, following the rules stated in the license of each package. For more information, see http://www.gnu.org/philosophy/free-sw.html. If you are looking for service or support for GNU software, see http://www.gnu.org/help/gethelp.html for suggestions of where to ask. If you would like to contribute to the development of one of these packages, contact the package maintainer or the bug-reporting address of the package (which should be listed in the package itself), or look on www.gnu.org for more information on how to contribute. @end smallexample @node Free Software Directory @chapter Free Software Directory @cindex Free Software Directory @cindex Directory, Free Software The Free Software Directory aims to be a complete list of free software packages, within certain criteria. Every GNU package should be listed there, so please see @url{http://www.gnu.org/help/directory.html#adding-entries} for information on how to write an entry for your package. Contact @email{bug-directory@@gnu.org} with any questions or suggestions for the Free Software Directory. @node Using the Proofreaders List @chapter Using the Proofreaders List @cindex proofreading If you want help finding errors in documentation, or help improving the quality of writing, or if you are not a native speaker of English and want help producing good English documentation, you can use the GNU proofreaders mailing list: @email{proofreaders@@gnu.org}. But be careful when you use the list, because there are over 200 people on it. If you simply ask everyone on the list to read your work, there will probably be tremendous duplication of effort by the proofreaders, and you will probably get the same errors reported 100 times. This must be avoided. Also, the people on the list do not want to get a large amount of mail from it. So do not ever ask people on the list to send mail to the list! Here are a few methods that seem reasonable to use: @itemize @bullet @item For something small, mail it to the list, and ask people to pick a random number from 1 to 20, and read it if the number comes out as 10. This way, assuming 50% response, some 5 people will read the piece. @item For a larger work, divide your work into around 20 equal-sized parts, tell people where to get it, and ask each person to pick randomly which part to read. Be sure to specify the random choice procedure; otherwise people will probably use a mental procedure that is not really random, such as ``pick a part near the middle'', and you will not get even coverage. You can either divide up the work physically, into 20 separate files, or describe a virtual division, such as by sections (if your work has approximately 20 sections). If you do the latter, be sure to be precise about it---for example, do you want the material before the first section heading to count as a section, or not? @item For a job needing special skills, send an explanation of it, and ask people to send you mail if they volunteer for the job. When you get enough volunteers, send another message to the list saying ``I have enough volunteers, no more please.'' @end itemize @node GNU Free Documentation License @appendix GNU Free Documentation License @cindex FDL, GNU Free Documentation License @include fdl.texi @node Index @unnumbered Index @printindex cp @bye Local variables: eval: (add-hook 'write-file-hooks 'time-stamp) time-stamp-start: "@set lastupdate " time-stamp-start: "@set lastupdate " time-stamp-end: "$" time-stamp-format: "%:b %:d, %:y" compile-command: "make -C work.m" End: ��������������������������������������gnu-standards-2010.03.11/make-stds.texi�������������������������������������������������������������0000664�0000000�0000000�00000133041�11351271455�0017442�0����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������@comment This file is included by both standards.texi and make.texinfo. @comment It was broken out of standards.texi on 1/6/93 by roland. @node Makefile Conventions @chapter Makefile Conventions @cindex makefile, conventions for @cindex conventions for makefiles @cindex standards for makefiles @c Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2000, 2001, @c 2004, 2005, 2006, 2007, 2008, 2010 Free Software Foundation, Inc. @c @c Permission is granted to copy, distribute and/or modify this document @c under the terms of the GNU Free Documentation License, Version 1.3 @c or any later version published by the Free Software Foundation; @c with no Invariant Sections, with no @c Front-Cover Texts, and with no Back-Cover Texts. @c A copy of the license is included in the section entitled ``GNU @c Free Documentation License''. This @ifinfo node @end ifinfo @iftex @ifset CODESTD section @end ifset @ifclear CODESTD chapter @end ifclear @end iftex describes conventions for writing the Makefiles for GNU programs. Using Automake will help you write a Makefile that follows these conventions. For more information on portable Makefiles, see @sc{posix} and @ref{Portable Make, Portable Make Programming,, autoconf, Autoconf}. @menu * Makefile Basics:: General conventions for Makefiles. * Utilities in Makefiles:: Utilities to be used in Makefiles. * Command Variables:: Variables for specifying commands. * DESTDIR:: Supporting staged installs. * Directory Variables:: Variables for installation directories. * Standard Targets:: Standard targets for users. * Install Command Categories:: Three categories of commands in the `install' rule: normal, pre-install and post-install. @end menu @node Makefile Basics @section General Conventions for Makefiles Every Makefile should contain this line: @example SHELL = /bin/sh @end example @noindent to avoid trouble on systems where the @code{SHELL} variable might be inherited from the environment. (This is never a problem with GNU @code{make}.) Different @code{make} programs have incompatible suffix lists and implicit rules, and this sometimes creates confusion or misbehavior. So it is a good idea to set the suffix list explicitly using only the suffixes you need in the particular Makefile, like this: @example .SUFFIXES: .SUFFIXES: .c .o @end example @noindent The first line clears out the suffix list, the second introduces all suffixes which may be subject to implicit rules in this Makefile. Don't assume that @file{.} is in the path for command execution. When you need to run programs that are a part of your package during the make, please make sure that it uses @file{./} if the program is built as part of the make or @file{$(srcdir)/} if the file is an unchanging part of the source code. Without one of these prefixes, the current search path is used. The distinction between @file{./} (the @dfn{build directory}) and @file{$(srcdir)/} (the @dfn{source directory}) is important because users can build in a separate directory using the @samp{--srcdir} option to @file{configure}. A rule of the form: @smallexample foo.1 : foo.man sedscript sed -f sedscript foo.man > foo.1 @end smallexample @noindent will fail when the build directory is not the source directory, because @file{foo.man} and @file{sedscript} are in the source directory. When using GNU @code{make}, relying on @samp{VPATH} to find the source file will work in the case where there is a single dependency file, since the @code{make} automatic variable @samp{$<} will represent the source file wherever it is. (Many versions of @code{make} set @samp{$<} only in implicit rules.) A Makefile target like @smallexample foo.o : bar.c $(CC) -I. -I$(srcdir) $(CFLAGS) -c bar.c -o foo.o @end smallexample @noindent should instead be written as @smallexample foo.o : bar.c $(CC) -I. -I$(srcdir) $(CFLAGS) -c $< -o $@@ @end smallexample @noindent in order to allow @samp{VPATH} to work correctly. When the target has multiple dependencies, using an explicit @samp{$(srcdir)} is the easiest way to make the rule work well. For example, the target above for @file{foo.1} is best written as: @smallexample foo.1 : foo.man sedscript sed -f $(srcdir)/sedscript $(srcdir)/foo.man > $@@ @end smallexample GNU distributions usually contain some files which are not source files---for example, Info files, and the output from Autoconf, Automake, Bison or Flex. Since these files normally appear in the source directory, they should always appear in the source directory, not in the build directory. So Makefile rules to update them should put the updated files in the source directory. However, if a file does not appear in the distribution, then the Makefile should not put it in the source directory, because building a program in ordinary circumstances should not modify the source directory in any way. Try to make the build and installation targets, at least (and all their subtargets) work correctly with a parallel @code{make}. @node Utilities in Makefiles @section Utilities in Makefiles Write the Makefile commands (and any shell scripts, such as @code{configure}) to run under @code{sh} (both the traditional Bourne shell and the @sc{posix} shell), not @code{csh}. Don't use any special features of @code{ksh} or @code{bash}, or @sc{posix} features not widely supported in traditional Bourne @code{sh}. The @code{configure} script and the Makefile rules for building and installation should not use any utilities directly except these: @c dd find @c gunzip gzip md5sum @c mkfifo mknod tee uname @example awk cat cmp cp diff echo egrep expr false grep install-info ln ls mkdir mv pwd rm rmdir sed sleep sort tar test touch tr true @end example Compression programs such as @code{gzip} can be used in the @code{dist} rule. Generally, stick to the widely-supported (usually @sc{posix}-specified) options and features of these programs. For example, don't use @samp{mkdir -p}, convenient as it may be, because a few systems don't support it at all and with others, it is not safe for parallel execution. For a list of known incompatibilities, see @ref{Portable Shell, Portable Shell Programming,, autoconf, Autoconf}. It is a good idea to avoid creating symbolic links in makefiles, since a few file systems don't support them. The Makefile rules for building and installation can also use compilers and related programs, but should do so via @code{make} variables so that the user can substitute alternatives. Here are some of the programs we mean: @example ar bison cc flex install ld ldconfig lex make makeinfo ranlib texi2dvi yacc @end example Use the following @code{make} variables to run those programs: @example $(AR) $(BISON) $(CC) $(FLEX) $(INSTALL) $(LD) $(LDCONFIG) $(LEX) $(MAKE) $(MAKEINFO) $(RANLIB) $(TEXI2DVI) $(YACC) @end example When you use @code{ranlib} or @code{ldconfig}, you should make sure nothing bad happens if the system does not have the program in question. Arrange to ignore an error from that command, and print a message before the command to tell the user that failure of this command does not mean a problem. (The Autoconf @samp{AC_PROG_RANLIB} macro can help with this.) If you use symbolic links, you should implement a fallback for systems that don't have symbolic links. Additional utilities that can be used via Make variables are: @example chgrp chmod chown mknod @end example It is ok to use other utilities in Makefile portions (or scripts) intended only for particular systems where you know those utilities exist. @node Command Variables @section Variables for Specifying Commands Makefiles should provide variables for overriding certain commands, options, and so on. In particular, you should run most utility programs via variables. Thus, if you use Bison, have a variable named @code{BISON} whose default value is set with @samp{BISON = bison}, and refer to it with @code{$(BISON)} whenever you need to use Bison. File management utilities such as @code{ln}, @code{rm}, @code{mv}, and so on, need not be referred to through variables in this way, since users don't need to replace them with other programs. Each program-name variable should come with an options variable that is used to supply options to the program. Append @samp{FLAGS} to the program-name variable name to get the options variable name---for example, @code{BISONFLAGS}. (The names @code{CFLAGS} for the C compiler, @code{YFLAGS} for yacc, and @code{LFLAGS} for lex, are exceptions to this rule, but we keep them because they are standard.) Use @code{CPPFLAGS} in any compilation command that runs the preprocessor, and use @code{LDFLAGS} in any compilation command that does linking as well as in any direct use of @code{ld}. If there are C compiler options that @emph{must} be used for proper compilation of certain files, do not include them in @code{CFLAGS}. Users expect to be able to specify @code{CFLAGS} freely themselves. Instead, arrange to pass the necessary options to the C compiler independently of @code{CFLAGS}, by writing them explicitly in the compilation commands or by defining an implicit rule, like this: @smallexample CFLAGS = -g ALL_CFLAGS = -I. $(CFLAGS) .c.o: $(CC) -c $(CPPFLAGS) $(ALL_CFLAGS) $< @end smallexample Do include the @samp{-g} option in @code{CFLAGS}, because that is not @emph{required} for proper compilation. You can consider it a default that is only recommended. If the package is set up so that it is compiled with GCC by default, then you might as well include @samp{-O} in the default value of @code{CFLAGS} as well. Put @code{CFLAGS} last in the compilation command, after other variables containing compiler options, so the user can use @code{CFLAGS} to override the others. @code{CFLAGS} should be used in every invocation of the C compiler, both those which do compilation and those which do linking. Every Makefile should define the variable @code{INSTALL}, which is the basic command for installing a file into the system. Every Makefile should also define the variables @code{INSTALL_PROGRAM} and @code{INSTALL_DATA}. (The default for @code{INSTALL_PROGRAM} should be @code{$(INSTALL)}; the default for @code{INSTALL_DATA} should be @code{$@{INSTALL@} -m 644}.) Then it should use those variables as the commands for actual installation, for executables and non-executables respectively. Minimal use of these variables is as follows: @example $(INSTALL_PROGRAM) foo $(bindir)/foo $(INSTALL_DATA) libfoo.a $(libdir)/libfoo.a @end example However, it is preferable to support a @code{DESTDIR} prefix on the target files, as explained in the next section. It is acceptable, but not required, to install multiple files in one command, with the final argument being a directory, as in: @example $(INSTALL_PROGRAM) foo bar baz $(bindir) @end example @node DESTDIR @section @code{DESTDIR}: Support for Staged Installs @vindex DESTDIR @cindex staged installs @cindex installations, staged @code{DESTDIR} is a variable prepended to each installed target file, like this: @example $(INSTALL_PROGRAM) foo $(DESTDIR)$(bindir)/foo $(INSTALL_DATA) libfoo.a $(DESTDIR)$(libdir)/libfoo.a @end example The @code{DESTDIR} variable is specified by the user on the @code{make} command line as an absolute file name. For example: @example make DESTDIR=/tmp/stage install @end example @noindent @code{DESTDIR} should be supported only in the @code{install*} and @code{uninstall*} targets, as those are the only targets where it is useful. If your installation step would normally install @file{/usr/local/bin/foo} and @file{/usr/local/lib/libfoo.a}, then an installation invoked as in the example above would install @file{/tmp/stage/usr/local/bin/foo} and @file{/tmp/stage/usr/local/lib/libfoo.a} instead. Prepending the variable @code{DESTDIR} to each target in this way provides for @dfn{staged installs}, where the installed files are not placed directly into their expected location but are instead copied into a temporary location (@code{DESTDIR}). However, installed files maintain their relative directory structure and any embedded file names will not be modified. You should not set the value of @code{DESTDIR} in your @file{Makefile} at all; then the files are installed into their expected locations by default. Also, specifying @code{DESTDIR} should not change the operation of the software in any way, so its value should not be included in any file contents. @code{DESTDIR} support is commonly used in package creation. It is also helpful to users who want to understand what a given package will install where, and to allow users who don't normally have permissions to install into protected areas to build and install before gaining those permissions. Finally, it can be useful with tools such as @code{stow}, where code is installed in one place but made to appear to be installed somewhere else using symbolic links or special mount operations. So, we strongly recommend GNU packages support @code{DESTDIR}, though it is not an absolute requirement. @node Directory Variables @section Variables for Installation Directories Installation directories should always be named by variables, so it is easy to install in a nonstandard place. The standard names for these variables and the values they should have in GNU packages are described below. They are based on a standard file system layout; variants of it are used in GNU/Linux and other modern operating systems. Installers are expected to override these values when calling @command{make} (e.g., @kbd{make prefix=/usr install} or @command{configure} (e.g., @kbd{configure --prefix=/usr}). GNU packages should not try to guess which value should be appropriate for these variables on the system they are being installed onto: use the default settings specified here so that all GNU packages behave identically, allowing the installer to achieve any desired layout. @cindex directories, creating installation @cindex installation directories, creating All installation directories, and their parent directories, should be created (if necessary) before they are installed into. These first two variables set the root for the installation. All the other installation directories should be subdirectories of one of these two, and nothing should be directly installed into these two directories. @table @code @item prefix @vindex prefix A prefix used in constructing the default values of the variables listed below. The default value of @code{prefix} should be @file{/usr/local}. When building the complete GNU system, the prefix will be empty and @file{/usr} will be a symbolic link to @file{/}. (If you are using Autoconf, write it as @samp{@@prefix@@}.) Running @samp{make install} with a different value of @code{prefix} from the one used to build the program should @emph{not} recompile the program. @item exec_prefix @vindex exec_prefix A prefix used in constructing the default values of some of the variables listed below. The default value of @code{exec_prefix} should be @code{$(prefix)}. (If you are using Autoconf, write it as @samp{@@exec_prefix@@}.) Generally, @code{$(exec_prefix)} is used for directories that contain machine-specific files (such as executables and subroutine libraries), while @code{$(prefix)} is used directly for other directories. Running @samp{make install} with a different value of @code{exec_prefix} from the one used to build the program should @emph{not} recompile the program. @end table Executable programs are installed in one of the following directories. @table @code @item bindir @vindex bindir The directory for installing executable programs that users can run. This should normally be @file{/usr/local/bin}, but write it as @file{$(exec_prefix)/bin}. (If you are using Autoconf, write it as @samp{@@bindir@@}.) @item sbindir @vindex sbindir The directory for installing executable programs that can be run from the shell, but are only generally useful to system administrators. This should normally be @file{/usr/local/sbin}, but write it as @file{$(exec_prefix)/sbin}. (If you are using Autoconf, write it as @samp{@@sbindir@@}.) @item libexecdir @vindex libexecdir @comment This paragraph adjusted to avoid overfull hbox --roland 5jul94 The directory for installing executable programs to be run by other programs rather than by users. This directory should normally be @file{/usr/local/libexec}, but write it as @file{$(exec_prefix)/libexec}. (If you are using Autoconf, write it as @samp{@@libexecdir@@}.) The definition of @samp{libexecdir} is the same for all packages, so you should install your data in a subdirectory thereof. Most packages install their data under @file{$(libexecdir)/@var{package-name}/}, possibly within additional subdirectories thereof, such as @file{$(libexecdir)/@var{package-name}/@var{machine}/@var{version}}. @end table Data files used by the program during its execution are divided into categories in two ways. @itemize @bullet @item Some files are normally modified by programs; others are never normally modified (though users may edit some of these). @item Some files are architecture-independent and can be shared by all machines at a site; some are architecture-dependent and can be shared only by machines of the same kind and operating system; others may never be shared between two machines. @end itemize This makes for six different possibilities. However, we want to discourage the use of architecture-dependent files, aside from object files and libraries. It is much cleaner to make other data files architecture-independent, and it is generally not hard. Here are the variables Makefiles should use to specify directories to put these various kinds of files in: @table @samp @item datarootdir The root of the directory tree for read-only architecture-independent data files. This should normally be @file{/usr/local/share}, but write it as @file{$(prefix)/share}. (If you are using Autoconf, write it as @samp{@@datarootdir@@}.) @samp{datadir}'s default value is based on this variable; so are @samp{infodir}, @samp{mandir}, and others. @item datadir The directory for installing idiosyncratic read-only architecture-independent data files for this program. This is usually the same place as @samp{datarootdir}, but we use the two separate variables so that you can move these program-specific files without altering the location for Info files, man pages, etc. This should normally be @file{/usr/local/share}, but write it as @file{$(datarootdir)}. (If you are using Autoconf, write it as @samp{@@datadir@@}.) The definition of @samp{datadir} is the same for all packages, so you should install your data in a subdirectory thereof. Most packages install their data under @file{$(datadir)/@var{package-name}/}. @item sysconfdir The directory for installing read-only data files that pertain to a single machine--that is to say, files for configuring a host. Mailer and network configuration files, @file{/etc/passwd}, and so forth belong here. All the files in this directory should be ordinary ASCII text files. This directory should normally be @file{/usr/local/etc}, but write it as @file{$(prefix)/etc}. (If you are using Autoconf, write it as @samp{@@sysconfdir@@}.) Do not install executables here in this directory (they probably belong in @file{$(libexecdir)} or @file{$(sbindir)}). Also do not install files that are modified in the normal course of their use (programs whose purpose is to change the configuration of the system excluded). Those probably belong in @file{$(localstatedir)}. @item sharedstatedir The directory for installing architecture-independent data files which the programs modify while they run. This should normally be @file{/usr/local/com}, but write it as @file{$(prefix)/com}. (If you are using Autoconf, write it as @samp{@@sharedstatedir@@}.) @item localstatedir The directory for installing data files which the programs modify while they run, and that pertain to one specific machine. Users should never need to modify files in this directory to configure the package's operation; put such configuration information in separate files that go in @file{$(datadir)} or @file{$(sysconfdir)}. @file{$(localstatedir)} should normally be @file{/usr/local/var}, but write it as @file{$(prefix)/var}. (If you are using Autoconf, write it as @samp{@@localstatedir@@}.) @end table These variables specify the directory for installing certain specific types of files, if your program has them. Every GNU package should have Info files, so every program needs @samp{infodir}, but not all need @samp{libdir} or @samp{lispdir}. @table @samp @item includedir @c rewritten to avoid overfull hbox --roland The directory for installing header files to be included by user programs with the C @samp{#include} preprocessor directive. This should normally be @file{/usr/local/include}, but write it as @file{$(prefix)/include}. (If you are using Autoconf, write it as @samp{@@includedir@@}.) Most compilers other than GCC do not look for header files in directory @file{/usr/local/include}. So installing the header files this way is only useful with GCC. Sometimes this is not a problem because some libraries are only really intended to work with GCC. But some libraries are intended to work with other compilers. They should install their header files in two places, one specified by @code{includedir} and one specified by @code{oldincludedir}. @item oldincludedir The directory for installing @samp{#include} header files for use with compilers other than GCC. This should normally be @file{/usr/include}. (If you are using Autoconf, you can write it as @samp{@@oldincludedir@@}.) The Makefile commands should check whether the value of @code{oldincludedir} is empty. If it is, they should not try to use it; they should cancel the second installation of the header files. A package should not replace an existing header in this directory unless the header came from the same package. Thus, if your Foo package provides a header file @file{foo.h}, then it should install the header file in the @code{oldincludedir} directory if either (1) there is no @file{foo.h} there or (2) the @file{foo.h} that exists came from the Foo package. To tell whether @file{foo.h} came from the Foo package, put a magic string in the file---part of a comment---and @code{grep} for that string. @item docdir The directory for installing documentation files (other than Info) for this package. By default, it should be @file{/usr/local/share/doc/@var{yourpkg}}, but it should be written as @file{$(datarootdir)/doc/@var{yourpkg}}. (If you are using Autoconf, write it as @samp{@@docdir@@}.) The @var{yourpkg} subdirectory, which may include a version number, prevents collisions among files with common names, such as @file{README}. @item infodir The directory for installing the Info files for this package. By default, it should be @file{/usr/local/share/info}, but it should be written as @file{$(datarootdir)/info}. (If you are using Autoconf, write it as @samp{@@infodir@@}.) @code{infodir} is separate from @code{docdir} for compatibility with existing practice. @item htmldir @itemx dvidir @itemx pdfdir @itemx psdir Directories for installing documentation files in the particular format. They should all be set to @code{$(docdir)} by default. (If you are using Autoconf, write them as @samp{@@htmldir@@}, @samp{@@dvidir@@}, etc.) Packages which supply several translations of their documentation should install them in @samp{$(htmldir)/}@var{ll}, @samp{$(pdfdir)/}@var{ll}, etc. where @var{ll} is a locale abbreviation such as @samp{en} or @samp{pt_BR}. @item libdir The directory for object files and libraries of object code. Do not install executables here, they probably ought to go in @file{$(libexecdir)} instead. The value of @code{libdir} should normally be @file{/usr/local/lib}, but write it as @file{$(exec_prefix)/lib}. (If you are using Autoconf, write it as @samp{@@libdir@@}.) @item lispdir The directory for installing any Emacs Lisp files in this package. By default, it should be @file{/usr/local/share/emacs/site-lisp}, but it should be written as @file{$(datarootdir)/emacs/site-lisp}. If you are using Autoconf, write the default as @samp{@@lispdir@@}. In order to make @samp{@@lispdir@@} work, you need the following lines in your @file{configure.in} file: @example lispdir='$@{datarootdir@}/emacs/site-lisp' AC_SUBST(lispdir) @end example @item localedir The directory for installing locale-specific message catalogs for this package. By default, it should be @file{/usr/local/share/locale}, but it should be written as @file{$(datarootdir)/locale}. (If you are using Autoconf, write it as @samp{@@localedir@@}.) This directory usually has a subdirectory per locale. @end table Unix-style man pages are installed in one of the following: @table @samp @item mandir The top-level directory for installing the man pages (if any) for this package. It will normally be @file{/usr/local/share/man}, but you should write it as @file{$(datarootdir)/man}. (If you are using Autoconf, write it as @samp{@@mandir@@}.) @item man1dir The directory for installing section 1 man pages. Write it as @file{$(mandir)/man1}. @item man2dir The directory for installing section 2 man pages. Write it as @file{$(mandir)/man2} @item @dots{} @strong{Don't make the primary documentation for any GNU software be a man page. Write a manual in Texinfo instead. Man pages are just for the sake of people running GNU software on Unix, which is a secondary application only.} @item manext The file name extension for the installed man page. This should contain a period followed by the appropriate digit; it should normally be @samp{.1}. @item man1ext The file name extension for installed section 1 man pages. @item man2ext The file name extension for installed section 2 man pages. @item @dots{} Use these names instead of @samp{manext} if the package needs to install man pages in more than one section of the manual. @end table And finally, you should set the following variable: @table @samp @item srcdir The directory for the sources being compiled. The value of this variable is normally inserted by the @code{configure} shell script. (If you are using Autoconf, use @samp{srcdir = @@srcdir@@}.) @end table For example: @smallexample @c I have changed some of the comments here slightly to fix an overfull @c hbox, so the make manual can format correctly. --roland # Common prefix for installation directories. # NOTE: This directory must exist when you start the install. prefix = /usr/local datarootdir = $(prefix)/share datadir = $(datarootdir) exec_prefix = $(prefix) # Where to put the executable for the command `gcc'. bindir = $(exec_prefix)/bin # Where to put the directories used by the compiler. libexecdir = $(exec_prefix)/libexec # Where to put the Info files. infodir = $(datarootdir)/info @end smallexample If your program installs a large number of files into one of the standard user-specified directories, it might be useful to group them into a subdirectory particular to that program. If you do this, you should write the @code{install} rule to create these subdirectories. Do not expect the user to include the subdirectory name in the value of any of the variables listed above. The idea of having a uniform set of variable names for installation directories is to enable the user to specify the exact same values for several different GNU packages. In order for this to be useful, all the packages must be designed so that they will work sensibly when the user does so. At times, not all of these variables may be implemented in the current release of Autoconf and/or Automake; but as of Autoconf@tie{}2.60, we believe all of them are. When any are missing, the descriptions here serve as specifications for what Autoconf will implement. As a programmer, you can either use a development version of Autoconf or avoid using these variables until a stable release is made which supports them. @node Standard Targets @section Standard Targets for Users All GNU programs should have the following targets in their Makefiles: @table @samp @item all Compile the entire program. This should be the default target. This target need not rebuild any documentation files; Info files should normally be included in the distribution, and DVI (and other documentation format) files should be made only when explicitly asked for. By default, the Make rules should compile and link with @samp{-g}, so that executable programs have debugging symbols. Users who don't mind being helpless can strip the executables later if they wish. @item install Compile the program and copy the executables, libraries, and so on to the file names where they should reside for actual use. If there is a simple test to verify that a program is properly installed, this target should run that test. Do not strip executables when installing them. Devil-may-care users can use the @code{install-strip} target to do that. If possible, write the @code{install} target rule so that it does not modify anything in the directory where the program was built, provided @samp{make all} has just been done. This is convenient for building the program under one user name and installing it under another. The commands should create all the directories in which files are to be installed, if they don't already exist. This includes the directories specified as the values of the variables @code{prefix} and @code{exec_prefix}, as well as all subdirectories that are needed. One way to do this is by means of an @code{installdirs} target as described below. Use @samp{-} before any command for installing a man page, so that @code{make} will ignore any errors. This is in case there are systems that don't have the Unix man page documentation system installed. The way to install Info files is to copy them into @file{$(infodir)} with @code{$(INSTALL_DATA)} (@pxref{Command Variables}), and then run the @code{install-info} program if it is present. @code{install-info} is a program that edits the Info @file{dir} file to add or update the menu entry for the given Info file; it is part of the Texinfo package. Here is a sample rule to install an Info file that also tries to handle some additional situations, such as @code{install-info} not being present. @comment This example has been carefully formatted for the Make manual. @comment Please do not reformat it without talking to bug-make@gnu.org. @smallexample do-install-info: foo.info installdirs $(NORMAL_INSTALL) # Prefer an info file in . to one in srcdir. if test -f foo.info; then d=.; \ else d="$(srcdir)"; fi; \ $(INSTALL_DATA) $$d/foo.info \ "$(DESTDIR)$(infodir)/foo.info" # Run install-info only if it exists. # Use `if' instead of just prepending `-' to the # line so we notice real errors from install-info. # Use `$(SHELL) -c' because some shells do not # fail gracefully when there is an unknown command. $(POST_INSTALL) if $(SHELL) -c 'install-info --version' \ >/dev/null 2>&1; then \ install-info --dir-file="$(DESTDIR)$(infodir)/dir" \ "$(DESTDIR)$(infodir)/foo.info"; \ else true; fi @end smallexample When writing the @code{install} target, you must classify all the commands into three categories: normal ones, @dfn{pre-installation} commands and @dfn{post-installation} commands. @xref{Install Command Categories}. @item install-html @itemx install-dvi @itemx install-pdf @itemx install-ps These targets install documentation in formats other than Info; they're intended to be called explicitly by the person installing the package, if that format is desired. GNU prefers Info files, so these must be installed by the @code{install} target. When you have many documentation files to install, we recommend that you avoid collisions and clutter by arranging for these targets to install in subdirectories of the appropriate installation directory, such as @code{htmldir}. As one example, if your package has multiple manuals, and you wish to install HTML documentation with many files (such as the ``split'' mode output by @code{makeinfo --html}), you'll certainly want to use subdirectories, or two nodes with the same name in different manuals will overwrite each other. Please make these @code{install-@var{format}} targets invoke the commands for the @var{format} target, for example, by making @var{format} a dependency. @item uninstall Delete all the installed files---the copies that the @samp{install} and @samp{install-*} targets create. This rule should not modify the directories where compilation is done, only the directories where files are installed. The uninstallation commands are divided into three categories, just like the installation commands. @xref{Install Command Categories}. @item install-strip Like @code{install}, but strip the executable files while installing them. In simple cases, this target can use the @code{install} target in a simple way: @smallexample install-strip: $(MAKE) INSTALL_PROGRAM='$(INSTALL_PROGRAM) -s' \ install @end smallexample But if the package installs scripts as well as real executables, the @code{install-strip} target can't just refer to the @code{install} target; it has to strip the executables but not the scripts. @code{install-strip} should not strip the executables in the build directory which are being copied for installation. It should only strip the copies that are installed. Normally we do not recommend stripping an executable unless you are sure the program has no bugs. However, it can be reasonable to install a stripped executable for actual execution while saving the unstripped executable elsewhere in case there is a bug. @comment The gratuitous blank line here is to make the table look better @comment in the printed Make manual. Please leave it in. @item clean Delete all files in the current directory that are normally created by building the program. Also delete files in other directories if they are created by this makefile. However, don't delete the files that record the configuration. Also preserve files that could be made by building, but normally aren't because the distribution comes with them. There is no need to delete parent directories that were created with @samp{mkdir -p}, since they could have existed anyway. Delete @file{.dvi} files here if they are not part of the distribution. @item distclean Delete all files in the current directory (or created by this makefile) that are created by configuring or building the program. If you have unpacked the source and built the program without creating any other files, @samp{make distclean} should leave only the files that were in the distribution. However, there is no need to delete parent directories that were created with @samp{mkdir -p}, since they could have existed anyway. @item mostlyclean Like @samp{clean}, but may refrain from deleting a few files that people normally don't want to recompile. For example, the @samp{mostlyclean} target for GCC does not delete @file{libgcc.a}, because recompiling it is rarely necessary and takes a lot of time. @item maintainer-clean Delete almost everything that can be reconstructed with this Makefile. This typically includes everything deleted by @code{distclean}, plus more: C source files produced by Bison, tags tables, Info files, and so on. The reason we say ``almost everything'' is that running the command @samp{make maintainer-clean} should not delete @file{configure} even if @file{configure} can be remade using a rule in the Makefile. More generally, @samp{make maintainer-clean} should not delete anything that needs to exist in order to run @file{configure} and then begin to build the program. Also, there is no need to delete parent directories that were created with @samp{mkdir -p}, since they could have existed anyway. These are the only exceptions; @code{maintainer-clean} should delete everything else that can be rebuilt. The @samp{maintainer-clean} target is intended to be used by a maintainer of the package, not by ordinary users. You may need special tools to reconstruct some of the files that @samp{make maintainer-clean} deletes. Since these files are normally included in the distribution, we don't take care to make them easy to reconstruct. If you find you need to unpack the full distribution again, don't blame us. To help make users aware of this, the commands for the special @code{maintainer-clean} target should start with these two: @smallexample @@echo 'This command is intended for maintainers to use; it' @@echo 'deletes files that may need special tools to rebuild.' @end smallexample @item TAGS Update a tags table for this program. @c ADR: how? @item info Generate any Info files needed. The best way to write the rules is as follows: @smallexample info: foo.info foo.info: foo.texi chap1.texi chap2.texi $(MAKEINFO) $(srcdir)/foo.texi @end smallexample @noindent You must define the variable @code{MAKEINFO} in the Makefile. It should run the @code{makeinfo} program, which is part of the Texinfo distribution. Normally a GNU distribution comes with Info files, and that means the Info files are present in the source directory. Therefore, the Make rule for an info file should update it in the source directory. When users build the package, ordinarily Make will not update the Info files because they will already be up to date. @item dvi @itemx html @itemx pdf @itemx ps Generate documentation files in the given format. These targets should always exist, but any or all can be a no-op if the given output format cannot be generated. These targets should not be dependencies of the @code{all} target; the user must manually invoke them. Here's an example rule for generating DVI files from Texinfo: @smallexample dvi: foo.dvi foo.dvi: foo.texi chap1.texi chap2.texi $(TEXI2DVI) $(srcdir)/foo.texi @end smallexample @noindent You must define the variable @code{TEXI2DVI} in the Makefile. It should run the program @code{texi2dvi}, which is part of the Texinfo distribution.@footnote{@code{texi2dvi} uses @TeX{} to do the real work of formatting. @TeX{} is not distributed with Texinfo.} Alternatively, write just the dependencies, and allow GNU @code{make} to provide the command. Here's another example, this one for generating HTML from Texinfo: @smallexample html: foo.html foo.html: foo.texi chap1.texi chap2.texi $(TEXI2HTML) $(srcdir)/foo.texi @end smallexample @noindent Again, you would define the variable @code{TEXI2HTML} in the Makefile; for example, it might run @code{makeinfo --no-split --html} (@command{makeinfo} is part of the Texinfo distribution). @item dist Create a distribution tar file for this program. The tar file should be set up so that the file names in the tar file start with a subdirectory name which is the name of the package it is a distribution for. This name can include the version number. For example, the distribution tar file of GCC version 1.40 unpacks into a subdirectory named @file{gcc-1.40}. The easiest way to do this is to create a subdirectory appropriately named, use @code{ln} or @code{cp} to install the proper files in it, and then @code{tar} that subdirectory. Compress the tar file with @code{gzip}. For example, the actual distribution file for GCC version 1.40 is called @file{gcc-1.40.tar.gz}. It is ok to support other free compression formats as well. The @code{dist} target should explicitly depend on all non-source files that are in the distribution, to make sure they are up to date in the distribution. @ifset CODESTD @xref{Releases, , Making Releases}. @end ifset @ifclear CODESTD @xref{Releases, , Making Releases, standards, GNU Coding Standards}. @end ifclear @item check Perform self-tests (if any). The user must build the program before running the tests, but need not install the program; you should write the self-tests so that they work when the program is built but not installed. @end table The following targets are suggested as conventional names, for programs in which they are useful. @table @code @item installcheck Perform installation tests (if any). The user must build and install the program before running the tests. You should not assume that @file{$(bindir)} is in the search path. @item installdirs It's useful to add a target named @samp{installdirs} to create the directories where files are installed, and their parent directories. There is a script called @file{mkinstalldirs} which is convenient for this; you can find it in the Gnulib package. You can use a rule like this: @comment This has been carefully formatted to look decent in the Make manual. @comment Please be sure not to make it extend any further to the right.--roland @smallexample # Make sure all installation directories (e.g. $(bindir)) # actually exist by making them if necessary. installdirs: mkinstalldirs $(srcdir)/mkinstalldirs $(bindir) $(datadir) \ $(libdir) $(infodir) \ $(mandir) @end smallexample @noindent or, if you wish to support @env{DESTDIR} (strongly encouraged), @smallexample # Make sure all installation directories (e.g. $(bindir)) # actually exist by making them if necessary. installdirs: mkinstalldirs $(srcdir)/mkinstalldirs \ $(DESTDIR)$(bindir) $(DESTDIR)$(datadir) \ $(DESTDIR)$(libdir) $(DESTDIR)$(infodir) \ $(DESTDIR)$(mandir) @end smallexample This rule should not modify the directories where compilation is done. It should do nothing but create installation directories. @end table @node Install Command Categories @section Install Command Categories @cindex pre-installation commands @cindex post-installation commands When writing the @code{install} target, you must classify all the commands into three categories: normal ones, @dfn{pre-installation} commands and @dfn{post-installation} commands. Normal commands move files into their proper places, and set their modes. They may not alter any files except the ones that come entirely from the package they belong to. Pre-installation and post-installation commands may alter other files; in particular, they can edit global configuration files or data bases. Pre-installation commands are typically executed before the normal commands, and post-installation commands are typically run after the normal commands. The most common use for a post-installation command is to run @code{install-info}. This cannot be done with a normal command, since it alters a file (the Info directory) which does not come entirely and solely from the package being installed. It is a post-installation command because it needs to be done after the normal command which installs the package's Info files. Most programs don't need any pre-installation commands, but we have the feature just in case it is needed. To classify the commands in the @code{install} rule into these three categories, insert @dfn{category lines} among them. A category line specifies the category for the commands that follow. A category line consists of a tab and a reference to a special Make variable, plus an optional comment at the end. There are three variables you can use, one for each category; the variable name specifies the category. Category lines are no-ops in ordinary execution because these three Make variables are normally undefined (and you @emph{should not} define them in the makefile). Here are the three possible category lines, each with a comment that explains what it means: @smallexample $(PRE_INSTALL) # @r{Pre-install commands follow.} $(POST_INSTALL) # @r{Post-install commands follow.} $(NORMAL_INSTALL) # @r{Normal commands follow.} @end smallexample If you don't use a category line at the beginning of the @code{install} rule, all the commands are classified as normal until the first category line. If you don't use any category lines, all the commands are classified as normal. These are the category lines for @code{uninstall}: @smallexample $(PRE_UNINSTALL) # @r{Pre-uninstall commands follow.} $(POST_UNINSTALL) # @r{Post-uninstall commands follow.} $(NORMAL_UNINSTALL) # @r{Normal commands follow.} @end smallexample Typically, a pre-uninstall command would be used for deleting entries from the Info directory. If the @code{install} or @code{uninstall} target has any dependencies which act as subroutines of installation, then you should start @emph{each} dependency's commands with a category line, and start the main target's commands with a category line also. This way, you can ensure that each command is placed in the right category regardless of which of the dependencies actually run. Pre-installation and post-installation commands should not run any programs except for these: @example [ basename bash cat chgrp chmod chown cmp cp dd diff echo egrep expand expr false fgrep find getopt grep gunzip gzip hostname install install-info kill ldconfig ln ls md5sum mkdir mkfifo mknod mv printenv pwd rm rmdir sed sort tee test touch true uname xargs yes @end example @cindex binary packages The reason for distinguishing the commands in this way is for the sake of making binary packages. Typically a binary package contains all the executables and other files that need to be installed, and has its own method of installing them---so it does not need to run the normal installation commands. But installing the binary package does need to execute the pre-installation and post-installation commands. Programs to build binary packages work by extracting the pre-installation and post-installation commands. Here is one way of extracting the pre-installation commands (the @option{-s} option to @command{make} is needed to silence messages about entering subdirectories): @smallexample make -s -n install -o all \ PRE_INSTALL=pre-install \ POST_INSTALL=post-install \ NORMAL_INSTALL=normal-install \ | gawk -f pre-install.awk @end smallexample @noindent where the file @file{pre-install.awk} could contain this: @smallexample $0 ~ /^(normal-install|post-install)[ \t]*$/ @{on = 0@} on @{print $0@} $0 ~ /^pre-install[ \t]*$/ @{on = 1@} @end smallexample �����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������gnu-standards-2010.03.11/standards.texi�������������������������������������������������������������0000664�0000000�0000000�00000427737�11351271455�0017557�0����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������\input texinfo @c -*-texinfo-*- @c %**start of header @setfilename standards.info @settitle GNU Coding Standards @c This date is automagically updated when you save this file: @set lastupdate March 11, 2010 @c %**end of header @dircategory GNU organization @direntry * Standards: (standards). GNU coding standards. @end direntry @c @setchapternewpage odd @setchapternewpage off @c Put everything in one index (arbitrarily chosen to be the concept index). @syncodeindex fn cp @syncodeindex ky cp @syncodeindex pg cp @syncodeindex vr cp @c This is used by a cross ref in make-stds.texi @set CODESTD 1 @copying The GNU coding standards, last updated @value{lastupdate}. Copyright @copyright{} 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. @end copying @titlepage @title GNU Coding Standards @author Richard Stallman, et al. @author last updated @value{lastupdate} @page @vskip 0pt plus 1filll @insertcopying @end titlepage @contents @ifnottex @node Top, Preface, (dir), (dir) @top Version @insertcopying @end ifnottex @menu * Preface:: About the GNU Coding Standards. * Legal Issues:: Keeping free software free. * Design Advice:: General program design. * Program Behavior:: Program behavior for all programs * Writing C:: Making the best use of C. * Documentation:: Documenting programs. * Managing Releases:: The release process. * References:: Mentioning non-free software or documentation. * GNU Free Documentation License:: Copying and sharing this manual. * Index:: @end menu @node Preface @chapter About the GNU Coding Standards The GNU Coding Standards were written by Richard Stallman and other GNU Project volunteers. Their purpose is to make the GNU system clean, consistent, and easy to install. This document can also be read as a guide to writing portable, robust and reliable programs. It focuses on programs written in C, but many of the rules and principles are useful even if you write in another programming language. The rules often state reasons for writing in a certain way. @cindex where to obtain @code{standards.texi} @cindex downloading this manual If you did not obtain this file directly from the GNU project and recently, please check for a newer version. You can get the GNU Coding Standards from the GNU web server in many different formats, including the Texinfo source, PDF, HTML, DVI, plain text, and more, at: @uref{http://www.gnu.org/prep/standards/}. If you are maintaining an official GNU package, in addition to this document, please read and follow the GNU maintainer information (@pxref{Top, , Contents, maintain, Information for Maintainers of GNU Software}). @cindex @code{gnustandards-commit@@gnu.org} mailing list If you want to receive diffs for every change to these GNU documents, join the mailing list @code{gnustandards-commit@@gnu.org}, via the web interface at @url{http://lists.gnu.org/mailman/listinfo/gnustandards-commit}. Archives are also available there. Corrections or suggestions for this document should be sent to @email{bug-standards@@gnu.org}. If you make a suggestion, please include a suggested new wording for it; our time is limited. We prefer a context diff to the @file{standards.texi} or @file{make-stds.texi} files, but if you don't have those files, please mail your suggestion anyway. These standards cover the minimum of what is important when writing a GNU package. Likely, the need for additional standards will come up. Sometimes, you might suggest that such standards be added to this document. If you think your standards would be generally useful, please do suggest them. You should also set standards for your package on many questions not addressed or not firmly specified here. The most important point is to be self-consistent---try to stick to the conventions you pick, and try to document them as much as possible. That way, your program will be more maintainable by others. The GNU Hello program serves as an example of how to follow the GNU coding standards for a trivial program. @uref{http://www.gnu.org/software/hello/hello.html}. This release of the GNU Coding Standards was last updated @value{lastupdate}. @node Legal Issues @chapter Keeping Free Software Free @cindex legal aspects This chapter discusses how you can make sure that GNU software avoids legal difficulties, and other related issues. @menu * Reading Non-Free Code:: Referring to proprietary programs. * Contributions:: Accepting contributions. * Trademarks:: How we deal with trademark issues. @end menu @node Reading Non-Free Code @section Referring to Proprietary Programs @cindex proprietary programs @cindex avoiding proprietary code Don't in any circumstances refer to Unix source code for or during your work on GNU! (Or to any other proprietary programs.) If you have a vague recollection of the internals of a Unix program, this does not absolutely mean you can't write an imitation of it, but do try to organize the imitation internally along different lines, because this is likely to make the details of the Unix version irrelevant and dissimilar to your results. For example, Unix utilities were generally optimized to minimize memory use; if you go for speed instead, your program will be very different. You could keep the entire input file in memory and scan it there instead of using stdio. Use a smarter algorithm discovered more recently than the Unix program. Eliminate use of temporary files. Do it in one pass instead of two (we did this in the assembler). Or, on the contrary, emphasize simplicity instead of speed. For some applications, the speed of today's computers makes simpler algorithms adequate. Or go for generality. For example, Unix programs often have static tables or fixed-size strings, which make for arbitrary limits; use dynamic allocation instead. Make sure your program handles NULs and other funny characters in the input files. Add a programming language for extensibility and write part of the program in that language. Or turn some parts of the program into independently usable libraries. Or use a simple garbage collector instead of tracking precisely when to free memory, or use a new GNU facility such as obstacks. @node Contributions @section Accepting Contributions @cindex legal papers @cindex accepting contributions If the program you are working on is copyrighted by the Free Software Foundation, then when someone else sends you a piece of code to add to the program, we need legal papers to use it---just as we asked you to sign papers initially. @emph{Each} person who makes a nontrivial contribution to a program must sign some sort of legal papers in order for us to have clear title to the program; the main author alone is not enough. So, before adding in any contributions from other people, please tell us, so we can arrange to get the papers. Then wait until we tell you that we have received the signed papers, before you actually use the contribution. This applies both before you release the program and afterward. If you receive diffs to fix a bug, and they make significant changes, we need legal papers for that change. This also applies to comments and documentation files. For copyright law, comments and code are just text. Copyright applies to all kinds of text, so we need legal papers for all kinds. We know it is frustrating to ask for legal papers; it's frustrating for us as well. But if you don't wait, you are going out on a limb---for example, what if the contributor's employer won't sign a disclaimer? You might have to take that code out again! You don't need papers for changes of a few lines here or there, since they are not significant for copyright purposes. Also, you don't need papers if all you get from the suggestion is some ideas, not actual code which you use. For example, if someone sent you one implementation, but you write a different implementation of the same idea, you don't need to get papers. The very worst thing is if you forget to tell us about the other contributor. We could be very embarrassed in court some day as a result. We have more detailed advice for maintainers of programs; if you have reached the stage of actually maintaining a program for GNU (whether released or not), please ask us for a copy. It is also available online for your perusal: @uref{http://www.gnu.org/prep/maintain/}. @node Trademarks @section Trademarks @cindex trademarks Please do not include any trademark acknowledgements in GNU software packages or documentation. Trademark acknowledgements are the statements that such-and-such is a trademark of so-and-so. The GNU Project has no objection to the basic idea of trademarks, but these acknowledgements feel like kowtowing, and there is no legal requirement for them, so we don't use them. What is legally required, as regards other people's trademarks, is to avoid using them in ways which a reader might reasonably understand as naming or labeling our own programs or activities. For example, since ``Objective C'' is (or at least was) a trademark, we made sure to say that we provide a ``compiler for the Objective C language'' rather than an ``Objective C compiler''. The latter would have been meant as a shorter way of saying the former, but it does not explicitly state the relationship, so it could be misinterpreted as using ``Objective C'' as a label for the compiler rather than for the language. Please don't use ``win'' as an abbreviation for Microsoft Windows in GNU software or documentation. In hacker terminology, calling something a ``win'' is a form of praise. If you wish to praise Microsoft Windows when speaking on your own, by all means do so, but not in GNU software. Usually we write the name ``Windows'' in full, but when brevity is very important (as in file names and sometimes symbol names), we abbreviate it to ``w''. For instance, the files and functions in Emacs that deal with Windows start with @samp{w32}. @node Design Advice @chapter General Program Design @cindex program design This chapter discusses some of the issues you should take into account when designing your program. @c Standard or ANSI C @c @c In 1989 the American National Standards Institute (ANSI) standardized @c C as standard X3.159-1989. In December of that year the @c International Standards Organization ISO adopted the ANSI C standard @c making minor changes. In 1990 ANSI then re-adopted ISO standard @c C. This version of C is known as either ANSI C or Standard C. @c A major revision of the C Standard appeared in 1999. @menu * Source Language:: Which languages to use. * Compatibility:: Compatibility with other implementations. * Using Extensions:: Using non-standard features. * Standard C:: Using standard C features. * Conditional Compilation:: Compiling code only if a conditional is true. @end menu @node Source Language @section Which Languages to Use @cindex programming languages When you want to use a language that gets compiled and runs at high speed, the best language to use is C. Using another language is like using a non-standard feature: it will cause trouble for users. Even if GCC supports the other language, users may find it inconvenient to have to install the compiler for that other language in order to build your program. For example, if you write your program in C++, people will have to install the GNU C++ compiler in order to compile your program. C has one other advantage over C++ and other compiled languages: more people know C, so more people will find it easy to read and modify the program if it is written in C. So in general it is much better to use C, rather than the comparable alternatives. But there are two exceptions to that conclusion: @itemize @bullet @item It is no problem to use another language to write a tool specifically intended for use with that language. That is because the only people who want to build the tool will be those who have installed the other language anyway. @item If an application is of interest only to a narrow part of the community, then the question of which language it is written in has less effect on other people, so you may as well please yourself. @end itemize Many programs are designed to be extensible: they include an interpreter for a language that is higher level than C. Often much of the program is written in that language, too. The Emacs editor pioneered this technique. @cindex Guile @cindex GNOME and Guile The standard extensibility interpreter for GNU software is Guile (@uref{http://www.gnu.org/@/software/@/guile/}), which implements the language Scheme (an especially clean and simple dialect of Lisp). Guile also includes bindings for GTK+/GNOME, making it practical to write modern GUI functionality within Guile. We don't reject programs written in other ``scripting languages'' such as Perl and Python, but using Guile is very important for the overall consistency of the GNU system. @node Compatibility @section Compatibility with Other Implementations @cindex compatibility with C and @sc{posix} standards @cindex @sc{posix} compatibility With occasional exceptions, utility programs and libraries for GNU should be upward compatible with those in Berkeley Unix, and upward compatible with Standard C if Standard C specifies their behavior, and upward compatible with @sc{posix} if @sc{posix} specifies their behavior. When these standards conflict, it is useful to offer compatibility modes for each of them. @cindex options for compatibility Standard C and @sc{posix} prohibit many kinds of extensions. Feel free to make the extensions anyway, and include a @samp{--ansi}, @samp{--posix}, or @samp{--compatible} option to turn them off. However, if the extension has a significant chance of breaking any real programs or scripts, then it is not really upward compatible. So you should try to redesign its interface to make it upward compatible. @cindex @code{POSIXLY_CORRECT}, environment variable Many GNU programs suppress extensions that conflict with @sc{posix} if the environment variable @code{POSIXLY_CORRECT} is defined (even if it is defined with a null value). Please make your program recognize this variable if appropriate. When a feature is used only by users (not by programs or command files), and it is done poorly in Unix, feel free to replace it completely with something totally different and better. (For example, @code{vi} is replaced with Emacs.) But it is nice to offer a compatible feature as well. (There is a free @code{vi} clone, so we offer it.) Additional useful features are welcome regardless of whether there is any precedent for them. @node Using Extensions @section Using Non-standard Features @cindex non-standard extensions Many GNU facilities that already exist support a number of convenient extensions over the comparable Unix facilities. Whether to use these extensions in implementing your program is a difficult question. On the one hand, using the extensions can make a cleaner program. On the other hand, people will not be able to build the program unless the other GNU tools are available. This might cause the program to work on fewer kinds of machines. With some extensions, it might be easy to provide both alternatives. For example, you can define functions with a ``keyword'' @code{INLINE} and define that as a macro to expand into either @code{inline} or nothing, depending on the compiler. In general, perhaps it is best not to use the extensions if you can straightforwardly do without them, but to use the extensions if they are a big improvement. An exception to this rule are the large, established programs (such as Emacs) which run on a great variety of systems. Using GNU extensions in such programs would make many users unhappy, so we don't do that. Another exception is for programs that are used as part of compilation: anything that must be compiled with other compilers in order to bootstrap the GNU compilation facilities. If these require the GNU compiler, then no one can compile them without having them installed already. That would be extremely troublesome in certain cases. @node Standard C @section Standard C and Pre-Standard C @cindex @sc{ansi} C standard 1989 Standard C is widespread enough now that it is ok to use its features in new programs. There is one exception: do not ever use the ``trigraph'' feature of Standard C. 1999 Standard C is not widespread yet, so please do not require its features in programs. It is ok to use its features if they are present. However, it is easy to support pre-standard compilers in most programs, so if you know how to do that, feel free. If a program you are maintaining has such support, you should try to keep it working. @cindex function prototypes To support pre-standard C, instead of writing function definitions in standard prototype form, @example int foo (int x, int y) @dots{} @end example @noindent write the definition in pre-standard style like this, @example int foo (x, y) int x, y; @dots{} @end example @noindent and use a separate declaration to specify the argument prototype: @example int foo (int, int); @end example You need such a declaration anyway, in a header file, to get the benefit of prototypes in all the files where the function is called. And once you have the declaration, you normally lose nothing by writing the function definition in the pre-standard style. This technique does not work for integer types narrower than @code{int}. If you think of an argument as being of a type narrower than @code{int}, declare it as @code{int} instead. There are a few special cases where this technique is hard to use. For example, if a function argument needs to hold the system type @code{dev_t}, you run into trouble, because @code{dev_t} is shorter than @code{int} on some machines; but you cannot use @code{int} instead, because @code{dev_t} is wider than @code{int} on some machines. There is no type you can safely use on all machines in a non-standard definition. The only way to support non-standard C and pass such an argument is to check the width of @code{dev_t} using Autoconf and choose the argument type accordingly. This may not be worth the trouble. In order to support pre-standard compilers that do not recognize prototypes, you may want to use a preprocessor macro like this: @example /* Declare the prototype for a general external function. */ #if defined (__STDC__) || defined (WINDOWSNT) #define P_(proto) proto #else #define P_(proto) () #endif @end example @node Conditional Compilation @section Conditional Compilation When supporting configuration options already known when building your program we prefer using @code{if (... )} over conditional compilation, as in the former case the compiler is able to perform more extensive checking of all possible code paths. For example, please write @smallexample if (HAS_FOO) ... else ... @end smallexample @noindent instead of: @smallexample #ifdef HAS_FOO ... #else ... #endif @end smallexample A modern compiler such as GCC will generate exactly the same code in both cases, and we have been using similar techniques with good success in several projects. Of course, the former method assumes that @code{HAS_FOO} is defined as either 0 or 1. While this is not a silver bullet solving all portability problems, and is not always appropriate, following this policy would have saved GCC developers many hours, or even days, per year. In the case of function-like macros like @code{REVERSIBLE_CC_MODE} in GCC which cannot be simply used in @code{if (...)} statements, there is an easy workaround. Simply introduce another macro @code{HAS_REVERSIBLE_CC_MODE} as in the following example: @smallexample #ifdef REVERSIBLE_CC_MODE #define HAS_REVERSIBLE_CC_MODE 1 #else #define HAS_REVERSIBLE_CC_MODE 0 #endif @end smallexample @node Program Behavior @chapter Program Behavior for All Programs This chapter describes conventions for writing robust software. It also describes general standards for error messages, the command line interface, and how libraries should behave. @menu * Non-GNU Standards:: We consider standards such as POSIX; we don't "obey" them. * Semantics:: Writing robust programs. * Libraries:: Library behavior. * Errors:: Formatting error messages. * User Interfaces:: Standards about interfaces generally. * Graphical Interfaces:: Standards for graphical interfaces. * Command-Line Interfaces:: Standards for command line interfaces. * Option Table:: Table of long options. * OID Allocations:: Table of OID slots for GNU. * Memory Usage:: When and how to care about memory needs. * File Usage:: Which files to use, and where. @end menu @node Non-GNU Standards @section Non-GNU Standards The GNU Project regards standards published by other organizations as suggestions, not orders. We consider those standards, but we do not ``obey'' them. In developing a GNU program, you should implement an outside standard's specifications when that makes the GNU system better overall in an objective sense. When it doesn't, you shouldn't. In most cases, following published standards is convenient for users---it means that their programs or scripts will work more portably. For instance, GCC implements nearly all the features of Standard C as specified by that standard. C program developers would be unhappy if it did not. And GNU utilities mostly follow specifications of POSIX.2; shell script writers and users would be unhappy if our programs were incompatible. But we do not follow either of these specifications rigidly, and there are specific points on which we decided not to follow them, so as to make the GNU system better for users. For instance, Standard C says that nearly all extensions to C are prohibited. How silly! GCC implements many extensions, some of which were later adopted as part of the standard. If you want these constructs to give an error message as ``required'' by the standard, you must specify @samp{--pedantic}, which was implemented only so that we can say ``GCC is a 100% implementation of the standard,'' not because there is any reason to actually use it. POSIX.2 specifies that @samp{df} and @samp{du} must output sizes by default in units of 512 bytes. What users want is units of 1k, so that is what we do by default. If you want the ridiculous behavior ``required'' by POSIX, you must set the environment variable @samp{POSIXLY_CORRECT} (which was originally going to be named @samp{POSIX_ME_HARDER}). GNU utilities also depart from the letter of the POSIX.2 specification when they support long-named command-line options, and intermixing options with ordinary arguments. This minor incompatibility with POSIX is never a problem in practice, and it is very useful. In particular, don't reject a new feature, or remove an old one, merely because a standard says it is ``forbidden'' or ``deprecated.'' @node Semantics @section Writing Robust Programs @cindex arbitrary limits on data Avoid arbitrary limits on the length or number of @emph{any} data structure, including file names, lines, files, and symbols, by allocating all data structures dynamically. In most Unix utilities, ``long lines are silently truncated''. This is not acceptable in a GNU utility. @cindex @code{NUL} characters Utilities reading files should not drop NUL characters, or any other nonprinting characters @emph{including those with codes above 0177}. The only sensible exceptions would be utilities specifically intended for interface to certain types of terminals or printers that can't handle those characters. Whenever possible, try to make programs work properly with sequences of bytes that represent multibyte characters, using encodings such as UTF-8 and others. @cindex error messages Check every system call for an error return, unless you know you wish to ignore errors. Include the system error text (from @code{perror} or equivalent) in @emph{every} error message resulting from a failing system call, as well as the name of the file if any and the name of the utility. Just ``cannot open foo.c'' or ``stat failed'' is not sufficient. @cindex @code{malloc} return value @cindex memory allocation failure Check every call to @code{malloc} or @code{realloc} to see if it returned zero. Check @code{realloc} even if you are making the block smaller; in a system that rounds block sizes to a power of 2, @code{realloc} may get a different block if you ask for less space. In Unix, @code{realloc} can destroy the storage block if it returns zero. GNU @code{realloc} does not have this bug: if it fails, the original block is unchanged. Feel free to assume the bug is fixed. If you wish to run your program on Unix, and wish to avoid lossage in this case, you can use the GNU @code{malloc}. You must expect @code{free} to alter the contents of the block that was freed. Anything you want to fetch from the block, you must fetch before calling @code{free}. If @code{malloc} fails in a noninteractive program, make that a fatal error. In an interactive program (one that reads commands from the user), it is better to abort the command and return to the command reader loop. This allows the user to kill other processes to free up virtual memory, and then try the command again. @cindex command-line arguments, decoding Use @code{getopt_long} to decode arguments, unless the argument syntax makes this unreasonable. When static storage is to be written in during program execution, use explicit C code to initialize it. Reserve C initialized declarations for data that will not be changed. @c ADR: why? Try to avoid low-level interfaces to obscure Unix data structures (such as file directories, utmp, or the layout of kernel memory), since these are less likely to work compatibly. If you need to find all the files in a directory, use @code{readdir} or some other high-level interface. These are supported compatibly by GNU. @cindex signal handling The preferred signal handling facilities are the BSD variant of @code{signal}, and the @sc{posix} @code{sigaction} function; the alternative USG @code{signal} interface is an inferior design. Nowadays, using the @sc{posix} signal functions may be the easiest way to make a program portable. If you use @code{signal}, then on GNU/Linux systems running GNU libc version 1, you should include @file{bsd/signal.h} instead of @file{signal.h}, so as to get BSD behavior. It is up to you whether to support systems where @code{signal} has only the USG behavior, or give up on them. @cindex impossible conditions In error checks that detect ``impossible'' conditions, just abort. There is usually no point in printing any message. These checks indicate the existence of bugs. Whoever wants to fix the bugs will have to read the source code and run a debugger. So explain the problem with comments in the source. The relevant data will be in variables, which are easy to examine with the debugger, so there is no point moving them elsewhere. Do not use a count of errors as the exit status for a program. @emph{That does not work}, because exit status values are limited to 8 bits (0 through 255). A single run of the program might have 256 errors; if you try to return 256 as the exit status, the parent process will see 0 as the status, and it will appear that the program succeeded. @cindex temporary files @cindex @code{TMPDIR} environment variable If you make temporary files, check the @code{TMPDIR} environment variable; if that variable is defined, use the specified directory instead of @file{/tmp}. In addition, be aware that there is a possible security problem when creating temporary files in world-writable directories. In C, you can avoid this problem by creating temporary files in this manner: @example fd = open (filename, O_WRONLY | O_CREAT | O_EXCL, 0600); @end example @noindent or by using the @code{mkstemps} function from libiberty. In bash, use @code{set -C} to avoid this problem. @node Libraries @section Library Behavior @cindex libraries Try to make library functions reentrant. If they need to do dynamic storage allocation, at least try to avoid any nonreentrancy aside from that of @code{malloc} itself. Here are certain name conventions for libraries, to avoid name conflicts. Choose a name prefix for the library, more than two characters long. All external function and variable names should start with this prefix. In addition, there should only be one of these in any given library member. This usually means putting each one in a separate source file. An exception can be made when two external symbols are always used together, so that no reasonable program could use one without the other; then they can both go in the same file. External symbols that are not documented entry points for the user should have names beginning with @samp{_}. The @samp{_} should be followed by the chosen name prefix for the library, to prevent collisions with other libraries. These can go in the same files with user entry points if you like. Static functions and variables can be used as you like and need not fit any naming convention. @node Errors @section Formatting Error Messages @cindex formatting error messages @cindex error messages, formatting Error messages from compilers should look like this: @example @var{source-file-name}:@var{lineno}: @var{message} @end example @noindent If you want to mention the column number, use one of these formats: @example @var{source-file-name}:@var{lineno}:@var{column}: @var{message} @var{source-file-name}:@var{lineno}.@var{column}: @var{message} @end example @noindent Line numbers should start from 1 at the beginning of the file, and column numbers should start from 1 at the beginning of the line. (Both of these conventions are chosen for compatibility.) Calculate column numbers assuming that space and all ASCII printing characters have equal width, and assuming tab stops every 8 columns. The error message can also give both the starting and ending positions of the erroneous text. There are several formats so that you can avoid redundant information such as a duplicate line number. Here are the possible formats: @example @var{source-file-name}:@var{lineno-1}.@var{column-1}-@var{lineno-2}.@var{column-2}: @var{message} @var{source-file-name}:@var{lineno-1}.@var{column-1}-@var{column-2}: @var{message} @var{source-file-name}:@var{lineno-1}-@var{lineno-2}: @var{message} @end example @noindent When an error is spread over several files, you can use this format: @example @var{file-1}:@var{lineno-1}.@var{column-1}-@var{file-2}:@var{lineno-2}.@var{column-2}: @var{message} @end example Error messages from other noninteractive programs should look like this: @example @var{program}:@var{source-file-name}:@var{lineno}: @var{message} @end example @noindent when there is an appropriate source file, or like this: @example @var{program}: @var{message} @end example @noindent when there is no relevant source file. If you want to mention the column number, use this format: @example @var{program}:@var{source-file-name}:@var{lineno}:@var{column}: @var{message} @end example In an interactive program (one that is reading commands from a terminal), it is better not to include the program name in an error message. The place to indicate which program is running is in the prompt or with the screen layout. (When the same program runs with input from a source other than a terminal, it is not interactive and would do best to print error messages using the noninteractive style.) The string @var{message} should not begin with a capital letter when it follows a program name and/or file name, because that isn't the beginning of a sentence. (The sentence conceptually starts at the beginning of the line.) Also, it should not end with a period. Error messages from interactive programs, and other messages such as usage messages, should start with a capital letter. But they should not end with a period. @node User Interfaces @section Standards for Interfaces Generally @cindex program name and its behavior @cindex behavior, dependent on program's name Please don't make the behavior of a utility depend on the name used to invoke it. It is useful sometimes to make a link to a utility with a different name, and that should not change what it does. Instead, use a run time option or a compilation switch or both to select among the alternate behaviors. @cindex output device and program's behavior Likewise, please don't make the behavior of the program depend on the type of output device it is used with. Device independence is an important principle of the system's design; do not compromise it merely to save someone from typing an option now and then. (Variation in error message syntax when using a terminal is ok, because that is a side issue that people do not depend on.) If you think one behavior is most useful when the output is to a terminal, and another is most useful when the output is a file or a pipe, then it is usually best to make the default behavior the one that is useful with output to a terminal, and have an option for the other behavior. Compatibility requires certain programs to depend on the type of output device. It would be disastrous if @code{ls} or @code{sh} did not do so in the way all users expect. In some of these cases, we supplement the program with a preferred alternate version that does not depend on the output device type. For example, we provide a @code{dir} program much like @code{ls} except that its default output format is always multi-column format. @node Graphical Interfaces @section Standards for Graphical Interfaces @cindex graphical user interface @cindex gtk+ When you write a program that provides a graphical user interface, please make it work with the X Window System and the GTK+ toolkit unless the functionality specifically requires some alternative (for example, ``displaying jpeg images while in console mode''). In addition, please provide a command-line interface to control the functionality. (In many cases, the graphical user interface can be a separate program which invokes the command-line program.) This is so that the same jobs can be done from scripts. @cindex corba @cindex gnome Please also consider providing a CORBA interface (for use from GNOME), a library interface (for use from C), and perhaps a keyboard-driven console interface (for use by users from console mode). Once you are doing the work to provide the functionality and the graphical interface, these won't be much extra work. @node Command-Line Interfaces @section Standards for Command Line Interfaces @cindex command-line interface @findex getopt It is a good idea to follow the @sc{posix} guidelines for the command-line options of a program. The easiest way to do this is to use @code{getopt} to parse them. Note that the GNU version of @code{getopt} will normally permit options anywhere among the arguments unless the special argument @samp{--} is used. This is not what @sc{posix} specifies; it is a GNU extension. @cindex long-named options Please define long-named options that are equivalent to the single-letter Unix-style options. We hope to make GNU more user friendly this way. This is easy to do with the GNU function @code{getopt_long}. One of the advantages of long-named options is that they can be consistent from program to program. For example, users should be able to expect the ``verbose'' option of any GNU program which has one, to be spelled precisely @samp{--verbose}. To achieve this uniformity, look at the table of common long-option names when you choose the option names for your program (@pxref{Option Table}). It is usually a good idea for file names given as ordinary arguments to be input files only; any output files would be specified using options (preferably @samp{-o} or @samp{--output}). Even if you allow an output file name as an ordinary argument for compatibility, try to provide an option as another way to specify it. This will lead to more consistency among GNU utilities, and fewer idiosyncrasies for users to remember. @cindex standard command-line options @cindex options, standard command-line @cindex CGI programs, standard options for @cindex PATH_INFO, specifying standard options as All programs should support two standard options: @samp{--version} and @samp{--help}. CGI programs should accept these as command-line options, and also if given as the @env{PATH_INFO}; for instance, visiting @url{http://example.org/p.cgi/--help} in a browser should output the same information as invoking @samp{p.cgi --help} from the command line. @menu * --version:: The standard output for --version. * --help:: The standard output for --help. @end menu @node --version @subsection @option{--version} @cindex @samp{--version} output The standard @code{--version} option should direct the program to print information about its name, version, origin and legal status, all on standard output, and then exit successfully. Other options and arguments should be ignored once this is seen, and the program should not perform its normal function. @cindex canonical name of a program @cindex program's canonical name The first line is meant to be easy for a program to parse; the version number proper starts after the last space. In addition, it contains the canonical name for this program, in this format: @example GNU Emacs 19.30 @end example @noindent The program's name should be a constant string; @emph{don't} compute it from @code{argv[0]}. The idea is to state the standard or canonical name for the program, not its file name. There are other ways to find out the precise file name where a command is found in @code{PATH}. If the program is a subsidiary part of a larger package, mention the package name in parentheses, like this: @example emacsserver (GNU Emacs) 19.30 @end example @noindent If the package has a version number which is different from this program's version number, you can mention the package version number just before the close-parenthesis. If you @emph{need} to mention the version numbers of libraries which are distributed separately from the package which contains this program, you can do so by printing an additional line of version info for each library you want to mention. Use the same format for these lines as for the first line. Please do not mention all of the libraries that the program uses ``just for completeness''---that would produce a lot of unhelpful clutter. Please mention library version numbers only if you find in practice that they are very important to you in debugging. The following line, after the version number line or lines, should be a copyright notice. If more than one copyright notice is called for, put each on a separate line. Next should follow a line stating the license, preferably using one of abbrevations below, and a brief statement that the program is free software, and that users are free to copy and change it. Also mention that there is no warranty, to the extent permitted by law. See recommended wording below. It is ok to finish the output with a list of the major authors of the program, as a way of giving credit. Here's an example of output that follows these rules: @smallexample GNU hello 2.3 Copyright (C) 2007 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. @end smallexample You should adapt this to your program, of course, filling in the proper year, copyright holder, name of program, and the references to distribution terms, and changing the rest of the wording as necessary. This copyright notice only needs to mention the most recent year in which changes were made---there's no need to list the years for previous versions' changes. You don't have to mention the name of the program in these notices, if that is inconvenient, since it appeared in the first line. (The rules are different for copyright notices in source files; @pxref{Copyright Notices,,,maintain,Information for GNU Maintainers}.) Translations of the above lines must preserve the validity of the copyright notices (@pxref{Internationalization}). If the translation's character set supports it, the @samp{(C)} should be replaced with the copyright symbol, as follows: @ifinfo (the official copyright symbol, which is the letter C in a circle); @end ifinfo @ifnotinfo @copyright{} @end ifnotinfo Write the word ``Copyright'' exactly like that, in English. Do not translate it into another language. International treaties recognize the English word ``Copyright''; translations into other languages do not have legal significance. Finally, here is the table of our suggested license abbreviations. Any abbreviation can be followed by @samp{v@var{version}[+]}, meaning that particular version, or later versions with the @samp{+}, as shown above. In the case of exceptions for extra permissions with the GPL, we use @samp{/} for a separator; the version number can follow the license abbreviation as usual, as in the examples below. @table @asis @item GPL GNU General Public License, @url{http://www.gnu.org/@/licenses/@/gpl.html}. @item LGPL GNU Lesser General Public License, @url{http://www.gnu.org/@/licenses/@/lgpl.html}. @item GPL/Guile GNU GPL with the exception for Guile; for example, GPLv3+/Guile means the GNU GPL version 3 or later, with the extra exception for Guile. @item GPL/Ada GNU GPL with the exception for Ada. @item Apache The Apache Software Foundation license, @url{http://www.apache.org/@/licenses}. @item Artistic The Artistic license used for Perl, @url{http://www.perlfoundation.org/@/legal}. @item Expat The Expat license, @url{http://www.jclark.com/@/xml/@/copying.txt}. @item MPL The Mozilla Public License, @url{http://www.mozilla.org/@/MPL/}. @item OBSD The original (4-clause) BSD license, incompatible with the GNU GPL @url{http://www.xfree86.org/@/3.3.6/@/COPYRIGHT2.html#6}. @item PHP The license used for PHP, @url{http://www.php.net/@/license/}. @item public domain The non-license that is being in the public domain, @url{http://www.gnu.org/@/licenses/@/license-list.html#PublicDomain}. @item Python The license for Python, @url{http://www.python.org/@/2.0.1/@/license.html}. @item RBSD The revised (3-clause) BSD, compatible with the GNU GPL, @url{http://www.xfree86.org/@/3.3.6/@/COPYRIGHT2.html#5}. @item X11 The simple non-copyleft license used for most versions of the X Window System, @url{http://www.xfree86.org/@/3.3.6/@/COPYRIGHT2.html#3}. @item Zlib The license for Zlib, @url{http://www.gzip.org/@/zlib/@/zlib_license.html}. @end table More information about these licenses and many more are on the GNU licensing web pages, @url{http://www.gnu.org/@/licenses/@/license-list.html}. @node --help @subsection @option{--help} @cindex @samp{--help} output The standard @code{--help} option should output brief documentation for how to invoke the program, on standard output, then exit successfully. Other options and arguments should be ignored once this is seen, and the program should not perform its normal function. @cindex address for bug reports @cindex bug reports Near the end of the @samp{--help} option's output, please place lines giving the email address for bug reports, the package's home page (normally @indicateurl{http://www.gnu.org/software/@var{pkg}}, and the general page for help using GNU programs. The format should be like this: @example Report bugs to: @var{mailing-address} @var{pkg} home page: <http://www.gnu.org/software/@var{pkg}/> General help using GNU software: <http://www.gnu.org/gethelp/> @end example It is ok to mention other appropriate mailing lists and web pages. @node Option Table @section Table of Long Options @cindex long option names @cindex table of long options Here is a table of long options used by GNU programs. It is surely incomplete, but we aim to list all the options that a new program might want to be compatible with. If you use names not already in the table, please send @email{bug-standards@@gnu.org} a list of them, with their meanings, so we can update the table. @c Please leave newlines between items in this table; it's much easier @c to update when it isn't completely squashed together and unreadable. @c When there is more than one short option for a long option name, put @c a semicolon between the lists of the programs that use them, not a @c period. --friedman @table @samp @item after-date @samp{-N} in @code{tar}. @item all @samp{-a} in @code{du}, @code{ls}, @code{nm}, @code{stty}, @code{uname}, and @code{unexpand}. @item all-text @samp{-a} in @code{diff}. @item almost-all @samp{-A} in @code{ls}. @item append @samp{-a} in @code{etags}, @code{tee}, @code{time}; @samp{-r} in @code{tar}. @item archive @samp{-a} in @code{cp}. @item archive-name @samp{-n} in @code{shar}. @item arglength @samp{-l} in @code{m4}. @item ascii @samp{-a} in @code{diff}. @item assign @samp{-v} in @code{gawk}. @item assume-new @samp{-W} in @code{make}. @item assume-old @samp{-o} in @code{make}. @item auto-check @samp{-a} in @code{recode}. @item auto-pager @samp{-a} in @code{wdiff}. @item auto-reference @samp{-A} in @code{ptx}. @item avoid-wraps @samp{-n} in @code{wdiff}. @item background For server programs, run in the background. @item backward-search @samp{-B} in @code{ctags}. @item basename @samp{-f} in @code{shar}. @item batch Used in GDB. @item baud Used in GDB. @item before @samp{-b} in @code{tac}. @item binary @samp{-b} in @code{cpio} and @code{diff}. @item bits-per-code @samp{-b} in @code{shar}. @item block-size Used in @code{cpio} and @code{tar}. @item blocks @samp{-b} in @code{head} and @code{tail}. @item break-file @samp{-b} in @code{ptx}. @item brief Used in various programs to make output shorter. @item bytes @samp{-c} in @code{head}, @code{split}, and @code{tail}. @item c@t{++} @samp{-C} in @code{etags}. @item catenate @samp{-A} in @code{tar}. @item cd Used in various programs to specify the directory to use. @item changes @samp{-c} in @code{chgrp} and @code{chown}. @item classify @samp{-F} in @code{ls}. @item colons @samp{-c} in @code{recode}. @item command @samp{-c} in @code{su}; @samp{-x} in GDB. @item compare @samp{-d} in @code{tar}. @item compat Used in @code{gawk}. @item compress @samp{-Z} in @code{tar} and @code{shar}. @item concatenate @samp{-A} in @code{tar}. @item confirmation @samp{-w} in @code{tar}. @item context Used in @code{diff}. @item copyleft @samp{-W copyleft} in @code{gawk}. @item copyright @samp{-C} in @code{ptx}, @code{recode}, and @code{wdiff}; @samp{-W copyright} in @code{gawk}. @item core Used in GDB. @item count @samp{-q} in @code{who}. @item count-links @samp{-l} in @code{du}. @item create Used in @code{tar} and @code{cpio}. @item cut-mark @samp{-c} in @code{shar}. @item cxref @samp{-x} in @code{ctags}. @item date @samp{-d} in @code{touch}. @item debug @samp{-d} in @code{make} and @code{m4}; @samp{-t} in Bison. @item define @samp{-D} in @code{m4}. @item defines @samp{-d} in Bison and @code{ctags}. @item delete @samp{-D} in @code{tar}. @item dereference @samp{-L} in @code{chgrp}, @code{chown}, @code{cpio}, @code{du}, @code{ls}, and @code{tar}. @item dereference-args @samp{-D} in @code{du}. @item device Specify an I/O device (special file name). @item diacritics @samp{-d} in @code{recode}. @item dictionary-order @samp{-d} in @code{look}. @item diff @samp{-d} in @code{tar}. @item digits @samp{-n} in @code{csplit}. @item directory Specify the directory to use, in various programs. In @code{ls}, it means to show directories themselves rather than their contents. In @code{rm} and @code{ln}, it means to not treat links to directories specially. @item discard-all @samp{-x} in @code{strip}. @item discard-locals @samp{-X} in @code{strip}. @item dry-run @samp{-n} in @code{make}. @item ed @samp{-e} in @code{diff}. @item elide-empty-files @samp{-z} in @code{csplit}. @item end-delete @samp{-x} in @code{wdiff}. @item end-insert @samp{-z} in @code{wdiff}. @item entire-new-file @samp{-N} in @code{diff}. @item environment-overrides @samp{-e} in @code{make}. @item eof @samp{-e} in @code{xargs}. @item epoch Used in GDB. @item error-limit Used in @code{makeinfo}. @item error-output @samp{-o} in @code{m4}. @item escape @samp{-b} in @code{ls}. @item exclude-from @samp{-X} in @code{tar}. @item exec Used in GDB. @item exit @samp{-x} in @code{xargs}. @item exit-0 @samp{-e} in @code{unshar}. @item expand-tabs @samp{-t} in @code{diff}. @item expression @samp{-e} in @code{sed}. @item extern-only @samp{-g} in @code{nm}. @item extract @samp{-i} in @code{cpio}; @samp{-x} in @code{tar}. @item faces @samp{-f} in @code{finger}. @item fast @samp{-f} in @code{su}. @item fatal-warnings @samp{-E} in @code{m4}. @item file @samp{-f} in @code{gawk}, @code{info}, @code{make}, @code{mt}, @code{sed}, and @code{tar}. @item field-separator @samp{-F} in @code{gawk}. @item file-prefix @samp{-b} in Bison. @item file-type @samp{-F} in @code{ls}. @item files-from @samp{-T} in @code{tar}. @item fill-column Used in @code{makeinfo}. @item flag-truncation @samp{-F} in @code{ptx}. @item fixed-output-files @samp{-y} in Bison. @item follow @samp{-f} in @code{tail}. @item footnote-style Used in @code{makeinfo}. @item force @samp{-f} in @code{cp}, @code{ln}, @code{mv}, and @code{rm}. @item force-prefix @samp{-F} in @code{shar}. @item foreground For server programs, run in the foreground; in other words, don't do anything special to run the server in the background. @item format Used in @code{ls}, @code{time}, and @code{ptx}. @item freeze-state @samp{-F} in @code{m4}. @item fullname Used in GDB. @item gap-size @samp{-g} in @code{ptx}. @item get @samp{-x} in @code{tar}. @item graphic @samp{-i} in @code{ul}. @item graphics @samp{-g} in @code{recode}. @item group @samp{-g} in @code{install}. @item gzip @samp{-z} in @code{tar} and @code{shar}. @item hashsize @samp{-H} in @code{m4}. @item header @samp{-h} in @code{objdump} and @code{recode} @item heading @samp{-H} in @code{who}. @item help Used to ask for brief usage information. @item here-delimiter @samp{-d} in @code{shar}. @item hide-control-chars @samp{-q} in @code{ls}. @item html In @code{makeinfo}, output HTML. @item idle @samp{-u} in @code{who}. @item ifdef @samp{-D} in @code{diff}. @item ignore @samp{-I} in @code{ls}; @samp{-x} in @code{recode}. @item ignore-all-space @samp{-w} in @code{diff}. @item ignore-backups @samp{-B} in @code{ls}. @item ignore-blank-lines @samp{-B} in @code{diff}. @item ignore-case @samp{-f} in @code{look} and @code{ptx}; @samp{-i} in @code{diff} and @code{wdiff}. @item ignore-errors @samp{-i} in @code{make}. @item ignore-file @samp{-i} in @code{ptx}. @item ignore-indentation @samp{-I} in @code{etags}. @item ignore-init-file @samp{-f} in Oleo. @item ignore-interrupts @samp{-i} in @code{tee}. @item ignore-matching-lines @samp{-I} in @code{diff}. @item ignore-space-change @samp{-b} in @code{diff}. @item ignore-zeros @samp{-i} in @code{tar}. @item include @samp{-i} in @code{etags}; @samp{-I} in @code{m4}. @item include-dir @samp{-I} in @code{make}. @item incremental @samp{-G} in @code{tar}. @item info @samp{-i}, @samp{-l}, and @samp{-m} in Finger. @item init-file In some programs, specify the name of the file to read as the user's init file. @item initial @samp{-i} in @code{expand}. @item initial-tab @samp{-T} in @code{diff}. @item inode @samp{-i} in @code{ls}. @item interactive @samp{-i} in @code{cp}, @code{ln}, @code{mv}, @code{rm}; @samp{-e} in @code{m4}; @samp{-p} in @code{xargs}; @samp{-w} in @code{tar}. @item intermix-type @samp{-p} in @code{shar}. @item iso-8601 Used in @code{date} @item jobs @samp{-j} in @code{make}. @item just-print @samp{-n} in @code{make}. @item keep-going @samp{-k} in @code{make}. @item keep-files @samp{-k} in @code{csplit}. @item kilobytes @samp{-k} in @code{du} and @code{ls}. @item language @samp{-l} in @code{etags}. @item less-mode @samp{-l} in @code{wdiff}. @item level-for-gzip @samp{-g} in @code{shar}. @item line-bytes @samp{-C} in @code{split}. @item lines Used in @code{split}, @code{head}, and @code{tail}. @item link @samp{-l} in @code{cpio}. @item lint @itemx lint-old Used in @code{gawk}. @item list @samp{-t} in @code{cpio}; @samp{-l} in @code{recode}. @item list @samp{-t} in @code{tar}. @item literal @samp{-N} in @code{ls}. @item load-average @samp{-l} in @code{make}. @item login Used in @code{su}. @item machine Used in @code{uname}. @item macro-name @samp{-M} in @code{ptx}. @item mail @samp{-m} in @code{hello} and @code{uname}. @item make-directories @samp{-d} in @code{cpio}. @item makefile @samp{-f} in @code{make}. @item mapped Used in GDB. @item max-args @samp{-n} in @code{xargs}. @item max-chars @samp{-n} in @code{xargs}. @item max-lines @samp{-l} in @code{xargs}. @item max-load @samp{-l} in @code{make}. @item max-procs @samp{-P} in @code{xargs}. @item mesg @samp{-T} in @code{who}. @item message @samp{-T} in @code{who}. @item minimal @samp{-d} in @code{diff}. @item mixed-uuencode @samp{-M} in @code{shar}. @item mode @samp{-m} in @code{install}, @code{mkdir}, and @code{mkfifo}. @item modification-time @samp{-m} in @code{tar}. @item multi-volume @samp{-M} in @code{tar}. @item name-prefix @samp{-a} in Bison. @item nesting-limit @samp{-L} in @code{m4}. @item net-headers @samp{-a} in @code{shar}. @item new-file @samp{-W} in @code{make}. @item no-builtin-rules @samp{-r} in @code{make}. @item no-character-count @samp{-w} in @code{shar}. @item no-check-existing @samp{-x} in @code{shar}. @item no-common @samp{-3} in @code{wdiff}. @item no-create @samp{-c} in @code{touch}. @item no-defines @samp{-D} in @code{etags}. @item no-deleted @samp{-1} in @code{wdiff}. @item no-dereference @samp{-d} in @code{cp}. @item no-inserted @samp{-2} in @code{wdiff}. @item no-keep-going @samp{-S} in @code{make}. @item no-lines @samp{-l} in Bison. @item no-piping @samp{-P} in @code{shar}. @item no-prof @samp{-e} in @code{gprof}. @item no-regex @samp{-R} in @code{etags}. @item no-sort @samp{-p} in @code{nm}. @item no-splash Don't print a startup splash screen. @item no-split Used in @code{makeinfo}. @item no-static @samp{-a} in @code{gprof}. @item no-time @samp{-E} in @code{gprof}. @item no-timestamp @samp{-m} in @code{shar}. @item no-validate Used in @code{makeinfo}. @item no-wait Used in @code{emacsclient}. @item no-warn Used in various programs to inhibit warnings. @item node @samp{-n} in @code{info}. @item nodename @samp{-n} in @code{uname}. @item nonmatching @samp{-f} in @code{cpio}. @item nstuff @samp{-n} in @code{objdump}. @item null @samp{-0} in @code{xargs}. @item number @samp{-n} in @code{cat}. @item number-nonblank @samp{-b} in @code{cat}. @item numeric-sort @samp{-n} in @code{nm}. @item numeric-uid-gid @samp{-n} in @code{cpio} and @code{ls}. @item nx Used in GDB. @item old-archive @samp{-o} in @code{tar}. @item old-file @samp{-o} in @code{make}. @item one-file-system @samp{-l} in @code{tar}, @code{cp}, and @code{du}. @item only-file @samp{-o} in @code{ptx}. @item only-prof @samp{-f} in @code{gprof}. @item only-time @samp{-F} in @code{gprof}. @item options @samp{-o} in @code{getopt}, @code{fdlist}, @code{fdmount}, @code{fdmountd}, and @code{fdumount}. @item output In various programs, specify the output file name. @item output-prefix @samp{-o} in @code{shar}. @item override @samp{-o} in @code{rm}. @item overwrite @samp{-c} in @code{unshar}. @item owner @samp{-o} in @code{install}. @item paginate @samp{-l} in @code{diff}. @item paragraph-indent Used in @code{makeinfo}. @item parents @samp{-p} in @code{mkdir} and @code{rmdir}. @item pass-all @samp{-p} in @code{ul}. @item pass-through @samp{-p} in @code{cpio}. @item port @samp{-P} in @code{finger}. @item portability @samp{-c} in @code{cpio} and @code{tar}. @item posix Used in @code{gawk}. @item prefix-builtins @samp{-P} in @code{m4}. @item prefix @samp{-f} in @code{csplit}. @item preserve Used in @code{tar} and @code{cp}. @item preserve-environment @samp{-p} in @code{su}. @item preserve-modification-time @samp{-m} in @code{cpio}. @item preserve-order @samp{-s} in @code{tar}. @item preserve-permissions @samp{-p} in @code{tar}. @item print @samp{-l} in @code{diff}. @item print-chars @samp{-L} in @code{cmp}. @item print-data-base @samp{-p} in @code{make}. @item print-directory @samp{-w} in @code{make}. @item print-file-name @samp{-o} in @code{nm}. @item print-symdefs @samp{-s} in @code{nm}. @item printer @samp{-p} in @code{wdiff}. @item prompt @samp{-p} in @code{ed}. @item proxy Specify an HTTP proxy. @item query-user @samp{-X} in @code{shar}. @item question @samp{-q} in @code{make}. @item quiet Used in many programs to inhibit the usual output. Every program accepting @samp{--quiet} should accept @samp{--silent} as a synonym. @item quiet-unshar @samp{-Q} in @code{shar} @item quote-name @samp{-Q} in @code{ls}. @item rcs @samp{-n} in @code{diff}. @item re-interval Used in @code{gawk}. @item read-full-blocks @samp{-B} in @code{tar}. @item readnow Used in GDB. @item recon @samp{-n} in @code{make}. @item record-number @samp{-R} in @code{tar}. @item recursive Used in @code{chgrp}, @code{chown}, @code{cp}, @code{ls}, @code{diff}, and @code{rm}. @item reference @samp{-r} in @code{touch}. @item references @samp{-r} in @code{ptx}. @item regex @samp{-r} in @code{tac} and @code{etags}. @item release @samp{-r} in @code{uname}. @item reload-state @samp{-R} in @code{m4}. @item relocation @samp{-r} in @code{objdump}. @item rename @samp{-r} in @code{cpio}. @item replace @samp{-i} in @code{xargs}. @item report-identical-files @samp{-s} in @code{diff}. @item reset-access-time @samp{-a} in @code{cpio}. @item reverse @samp{-r} in @code{ls} and @code{nm}. @item reversed-ed @samp{-f} in @code{diff}. @item right-side-defs @samp{-R} in @code{ptx}. @item same-order @samp{-s} in @code{tar}. @item same-permissions @samp{-p} in @code{tar}. @item save @samp{-g} in @code{stty}. @item se Used in GDB. @item sentence-regexp @samp{-S} in @code{ptx}. @item separate-dirs @samp{-S} in @code{du}. @item separator @samp{-s} in @code{tac}. @item sequence Used by @code{recode} to chose files or pipes for sequencing passes. @item shell @samp{-s} in @code{su}. @item show-all @samp{-A} in @code{cat}. @item show-c-function @samp{-p} in @code{diff}. @item show-ends @samp{-E} in @code{cat}. @item show-function-line @samp{-F} in @code{diff}. @item show-tabs @samp{-T} in @code{cat}. @item silent Used in many programs to inhibit the usual output. Every program accepting @samp{--silent} should accept @samp{--quiet} as a synonym. @item size @samp{-s} in @code{ls}. @item socket Specify a file descriptor for a network server to use for its socket, instead of opening and binding a new socket. This provides a way to run, in a non-privileged process, a server that normally needs a reserved port number. @item sort Used in @code{ls}. @item source @samp{-W source} in @code{gawk}. @item sparse @samp{-S} in @code{tar}. @item speed-large-files @samp{-H} in @code{diff}. @item split-at @samp{-E} in @code{unshar}. @item split-size-limit @samp{-L} in @code{shar}. @item squeeze-blank @samp{-s} in @code{cat}. @item start-delete @samp{-w} in @code{wdiff}. @item start-insert @samp{-y} in @code{wdiff}. @item starting-file Used in @code{tar} and @code{diff} to specify which file within a directory to start processing with. @item statistics @samp{-s} in @code{wdiff}. @item stdin-file-list @samp{-S} in @code{shar}. @item stop @samp{-S} in @code{make}. @item strict @samp{-s} in @code{recode}. @item strip @samp{-s} in @code{install}. @item strip-all @samp{-s} in @code{strip}. @item strip-debug @samp{-S} in @code{strip}. @item submitter @samp{-s} in @code{shar}. @item suffix @samp{-S} in @code{cp}, @code{ln}, @code{mv}. @item suffix-format @samp{-b} in @code{csplit}. @item sum @samp{-s} in @code{gprof}. @item summarize @samp{-s} in @code{du}. @item symbolic @samp{-s} in @code{ln}. @item symbols Used in GDB and @code{objdump}. @item synclines @samp{-s} in @code{m4}. @item sysname @samp{-s} in @code{uname}. @item tabs @samp{-t} in @code{expand} and @code{unexpand}. @item tabsize @samp{-T} in @code{ls}. @item terminal @samp{-T} in @code{tput} and @code{ul}. @samp{-t} in @code{wdiff}. @item text @samp{-a} in @code{diff}. @item text-files @samp{-T} in @code{shar}. @item time Used in @code{ls} and @code{touch}. @item timeout Specify how long to wait before giving up on some operation. @item to-stdout @samp{-O} in @code{tar}. @item total @samp{-c} in @code{du}. @item touch @samp{-t} in @code{make}, @code{ranlib}, and @code{recode}. @item trace @samp{-t} in @code{m4}. @item traditional @samp{-t} in @code{hello}; @samp{-W traditional} in @code{gawk}; @samp{-G} in @code{ed}, @code{m4}, and @code{ptx}. @item tty Used in GDB. @item typedefs @samp{-t} in @code{ctags}. @item typedefs-and-c++ @samp{-T} in @code{ctags}. @item typeset-mode @samp{-t} in @code{ptx}. @item uncompress @samp{-z} in @code{tar}. @item unconditional @samp{-u} in @code{cpio}. @item undefine @samp{-U} in @code{m4}. @item undefined-only @samp{-u} in @code{nm}. @item update @samp{-u} in @code{cp}, @code{ctags}, @code{mv}, @code{tar}. @item usage Used in @code{gawk}; same as @samp{--help}. @item uuencode @samp{-B} in @code{shar}. @item vanilla-operation @samp{-V} in @code{shar}. @item verbose Print more information about progress. Many programs support this. @item verify @samp{-W} in @code{tar}. @item version Print the version number. @item version-control @samp{-V} in @code{cp}, @code{ln}, @code{mv}. @item vgrind @samp{-v} in @code{ctags}. @item volume @samp{-V} in @code{tar}. @item what-if @samp{-W} in @code{make}. @item whole-size-limit @samp{-l} in @code{shar}. @item width @samp{-w} in @code{ls} and @code{ptx}. @item word-regexp @samp{-W} in @code{ptx}. @item writable @samp{-T} in @code{who}. @item zeros @samp{-z} in @code{gprof}. @end table @node OID Allocations @section OID Allocations @cindex OID allocations for GNU @cindex SNMP @cindex LDAP @cindex X.509 The OID (object identifier) 1.3.6.1.4.1.11591 has been assigned to the GNU Project (thanks to Werner Koch). These are used for SNMP, LDAP, X.509 certificates, and so on. The web site @url{http://www.alvestrand.no/objectid} has a (voluntary) listing of many OID assignments. If you need a new slot for your GNU package, write @email{maintainers@@gnu.org}. Here is a list of arcs currently assigned: @example @include gnu-oids.texi @end example @node Memory Usage @section Memory Usage @cindex memory usage If a program typically uses just a few meg of memory, don't bother making any effort to reduce memory usage. For example, if it is impractical for other reasons to operate on files more than a few meg long, it is reasonable to read entire input files into memory to operate on them. However, for programs such as @code{cat} or @code{tail}, that can usefully operate on very large files, it is important to avoid using a technique that would artificially limit the size of files it can handle. If a program works by lines and could be applied to arbitrary user-supplied input files, it should keep only a line in memory, because this is not very hard and users will want to be able to operate on input files that are bigger than will fit in memory all at once. If your program creates complicated data structures, just make them in memory and give a fatal error if @code{malloc} returns zero. @node File Usage @section File Usage @cindex file usage Programs should be prepared to operate when @file{/usr} and @file{/etc} are read-only file systems. Thus, if the program manages log files, lock files, backup files, score files, or any other files which are modified for internal purposes, these files should not be stored in @file{/usr} or @file{/etc}. There are two exceptions. @file{/etc} is used to store system configuration information; it is reasonable for a program to modify files in @file{/etc} when its job is to update the system configuration. Also, if the user explicitly asks to modify one file in a directory, it is reasonable for the program to store other files in the same directory. @node Writing C @chapter Making The Best Use of C This chapter provides advice on how best to use the C language when writing GNU software. @menu * Formatting:: Formatting your source code. * Comments:: Commenting your work. * Syntactic Conventions:: Clean use of C constructs. * Names:: Naming variables, functions, and files. * System Portability:: Portability among different operating systems. * CPU Portability:: Supporting the range of CPU types. * System Functions:: Portability and ``standard'' library functions. * Internationalization:: Techniques for internationalization. * Character Set:: Use ASCII by default. * Quote Characters:: Use `...' in the C locale. * Mmap:: How you can safely use @code{mmap}. @end menu @node Formatting @section Formatting Your Source Code @cindex formatting source code @cindex open brace @cindex braces, in C source It is important to put the open-brace that starts the body of a C function in column one, so that they will start a defun. Several tools look for open-braces in column one to find the beginnings of C functions. These tools will not work on code not formatted that way. Avoid putting open-brace, open-parenthesis or open-bracket in column one when they are inside a function, so that they won't start a defun. The open-brace that starts a @code{struct} body can go in column one if you find it useful to treat that definition as a defun. It is also important for function definitions to start the name of the function in column one. This helps people to search for function definitions, and may also help certain tools recognize them. Thus, using Standard C syntax, the format is this: @example static char * concat (char *s1, char *s2) @{ @dots{} @} @end example @noindent or, if you want to use traditional C syntax, format the definition like this: @example static char * concat (s1, s2) /* Name starts in column one here */ char *s1, *s2; @{ /* Open brace in column one here */ @dots{} @} @end example In Standard C, if the arguments don't fit nicely on one line, split it like this: @example int lots_of_args (int an_integer, long a_long, short a_short, double a_double, float a_float) @dots{} @end example The rest of this section gives our recommendations for other aspects of C formatting style, which is also the default style of the @code{indent} program in version 1.2 and newer. It corresponds to the options @smallexample -nbad -bap -nbc -bbo -bl -bli2 -bls -ncdb -nce -cp1 -cs -di2 -ndj -nfc1 -nfca -hnl -i2 -ip5 -lp -pcs -psl -nsc -nsob @end smallexample We don't think of these recommendations as requirements, because it causes no problems for users if two different programs have different formatting styles. But whatever style you use, please use it consistently, since a mixture of styles within one program tends to look ugly. If you are contributing changes to an existing program, please follow the style of that program. For the body of the function, our recommended style looks like this: @example if (x < foo (y, z)) haha = bar[4] + 5; else @{ while (z) @{ haha += foo (z, z); z--; @} return ++x + bar (); @} @end example @cindex spaces before open-paren We find it easier to read a program when it has spaces before the open-parentheses and after the commas. Especially after the commas. When you split an expression into multiple lines, split it before an operator, not after one. Here is the right way: @cindex expressions, splitting @example if (foo_this_is_long && bar > win (x, y, z) && remaining_condition) @end example Try to avoid having two operators of different precedence at the same level of indentation. For example, don't write this: @example mode = (inmode[j] == VOIDmode || GET_MODE_SIZE (outmode[j]) > GET_MODE_SIZE (inmode[j]) ? outmode[j] : inmode[j]); @end example Instead, use extra parentheses so that the indentation shows the nesting: @example mode = ((inmode[j] == VOIDmode || (GET_MODE_SIZE (outmode[j]) > GET_MODE_SIZE (inmode[j]))) ? outmode[j] : inmode[j]); @end example Insert extra parentheses so that Emacs will indent the code properly. For example, the following indentation looks nice if you do it by hand, @example v = rup->ru_utime.tv_sec*1000 + rup->ru_utime.tv_usec/1000 + rup->ru_stime.tv_sec*1000 + rup->ru_stime.tv_usec/1000; @end example @noindent but Emacs would alter it. Adding a set of parentheses produces something that looks equally nice, and which Emacs will preserve: @example v = (rup->ru_utime.tv_sec*1000 + rup->ru_utime.tv_usec/1000 + rup->ru_stime.tv_sec*1000 + rup->ru_stime.tv_usec/1000); @end example Format do-while statements like this: @example do @{ a = foo (a); @} while (a > 0); @end example @cindex formfeed @cindex control-L Please use formfeed characters (control-L) to divide the program into pages at logical places (but not within a function). It does not matter just how long the pages are, since they do not have to fit on a printed page. The formfeeds should appear alone on lines by themselves. @node Comments @section Commenting Your Work @cindex commenting Every program should start with a comment saying briefly what it is for. Example: @samp{fmt - filter for simple filling of text}. This comment should be at the top of the source file containing the @samp{main} function of the program. Also, please write a brief comment at the start of each source file, with the file name and a line or two about the overall purpose of the file. Please write the comments in a GNU program in English, because English is the one language that nearly all programmers in all countries can read. If you do not write English well, please write comments in English as well as you can, then ask other people to help rewrite them. If you can't write comments in English, please find someone to work with you and translate your comments into English. Please put a comment on each function saying what the function does, what sorts of arguments it gets, and what the possible values of arguments mean and are used for. It is not necessary to duplicate in words the meaning of the C argument declarations, if a C type is being used in its customary fashion. If there is anything nonstandard about its use (such as an argument of type @code{char *} which is really the address of the second character of a string, not the first), or any possible values that would not work the way one would expect (such as, that strings containing newlines are not guaranteed to work), be sure to say so. Also explain the significance of the return value, if there is one. Please put two spaces after the end of a sentence in your comments, so that the Emacs sentence commands will work. Also, please write complete sentences and capitalize the first word. If a lower-case identifier comes at the beginning of a sentence, don't capitalize it! Changing the spelling makes it a different identifier. If you don't like starting a sentence with a lower case letter, write the sentence differently (e.g., ``The identifier lower-case is @dots{}''). The comment on a function is much clearer if you use the argument names to speak about the argument values. The variable name itself should be lower case, but write it in upper case when you are speaking about the value rather than the variable itself. Thus, ``the inode number NODE_NUM'' rather than ``an inode''. There is usually no purpose in restating the name of the function in the comment before it, because the reader can see that for himself. There might be an exception when the comment is so long that the function itself would be off the bottom of the screen. There should be a comment on each static variable as well, like this: @example /* Nonzero means truncate lines in the display; zero means continue them. */ int truncate_lines; @end example @cindex conditionals, comments for @cindex @code{#endif}, commenting Every @samp{#endif} should have a comment, except in the case of short conditionals (just a few lines) that are not nested. The comment should state the condition of the conditional that is ending, @emph{including its sense}. @samp{#else} should have a comment describing the condition @emph{and sense} of the code that follows. For example: @example @group #ifdef foo @dots{} #else /* not foo */ @dots{} #endif /* not foo */ @end group @group #ifdef foo @dots{} #endif /* foo */ @end group @end example @noindent but, by contrast, write the comments this way for a @samp{#ifndef}: @example @group #ifndef foo @dots{} #else /* foo */ @dots{} #endif /* foo */ @end group @group #ifndef foo @dots{} #endif /* not foo */ @end group @end example @node Syntactic Conventions @section Clean Use of C Constructs @cindex syntactic conventions @cindex implicit @code{int} @cindex function argument, declaring Please explicitly declare the types of all objects. For example, you should explicitly declare all arguments to functions, and you should declare functions to return @code{int} rather than omitting the @code{int}. @cindex compiler warnings @cindex @samp{-Wall} compiler option Some programmers like to use the GCC @samp{-Wall} option, and change the code whenever it issues a warning. If you want to do this, then do. Other programmers prefer not to use @samp{-Wall}, because it gives warnings for valid and legitimate code which they do not want to change. If you want to do this, then do. The compiler should be your servant, not your master. Declarations of external functions and functions to appear later in the source file should all go in one place near the beginning of the file (somewhere before the first function definition in the file), or else should go in a header file. Don't put @code{extern} declarations inside functions. @cindex temporary variables It used to be common practice to use the same local variables (with names like @code{tem}) over and over for different values within one function. Instead of doing this, it is better to declare a separate local variable for each distinct purpose, and give it a name which is meaningful. This not only makes programs easier to understand, it also facilitates optimization by good compilers. You can also move the declaration of each local variable into the smallest scope that includes all its uses. This makes the program even cleaner. Don't use local variables or parameters that shadow global identifiers. @cindex multiple variables in a line Don't declare multiple variables in one declaration that spans lines. Start a new declaration on each line, instead. For example, instead of this: @example @group int foo, bar; @end group @end example @noindent write either this: @example int foo, bar; @end example @noindent or this: @example int foo; int bar; @end example @noindent (If they are global variables, each should have a comment preceding it anyway.) When you have an @code{if}-@code{else} statement nested in another @code{if} statement, always put braces around the @code{if}-@code{else}. Thus, never write like this: @example if (foo) if (bar) win (); else lose (); @end example @noindent always like this: @example if (foo) @{ if (bar) win (); else lose (); @} @end example If you have an @code{if} statement nested inside of an @code{else} statement, either write @code{else if} on one line, like this, @example if (foo) @dots{} else if (bar) @dots{} @end example @noindent with its @code{then}-part indented like the preceding @code{then}-part, or write the nested @code{if} within braces like this: @example if (foo) @dots{} else @{ if (bar) @dots{} @} @end example Don't declare both a structure tag and variables or typedefs in the same declaration. Instead, declare the structure tag separately and then use it to declare the variables or typedefs. Try to avoid assignments inside @code{if}-conditions (assignments inside @code{while}-conditions are ok). For example, don't write this: @example if ((foo = (char *) malloc (sizeof *foo)) == 0) fatal ("virtual memory exhausted"); @end example @noindent instead, write this: @example foo = (char *) malloc (sizeof *foo); if (foo == 0) fatal ("virtual memory exhausted"); @end example @pindex lint Don't make the program ugly to placate @code{lint}. Please don't insert any casts to @code{void}. Zero without a cast is perfectly fine as a null pointer constant, except when calling a varargs function. @node Names @section Naming Variables, Functions, and Files @cindex names of variables, functions, and files The names of global variables and functions in a program serve as comments of a sort. So don't choose terse names---instead, look for names that give useful information about the meaning of the variable or function. In a GNU program, names should be English, like other comments. Local variable names can be shorter, because they are used only within one context, where (presumably) comments explain their purpose. Try to limit your use of abbreviations in symbol names. It is ok to make a few abbreviations, explain what they mean, and then use them frequently, but don't use lots of obscure abbreviations. Please use underscores to separate words in a name, so that the Emacs word commands can be useful within them. Stick to lower case; reserve upper case for macros and @code{enum} constants, and for name-prefixes that follow a uniform convention. For example, you should use names like @code{ignore_space_change_flag}; don't use names like @code{iCantReadThis}. Variables that indicate whether command-line options have been specified should be named after the meaning of the option, not after the option-letter. A comment should state both the exact meaning of the option and its letter. For example, @example @group /* Ignore changes in horizontal whitespace (-b). */ int ignore_space_change_flag; @end group @end example When you want to define names with constant integer values, use @code{enum} rather than @samp{#define}. GDB knows about enumeration constants. @cindex file-name limitations @pindex doschk You might want to make sure that none of the file names would conflict if the files were loaded onto an MS-DOS file system which shortens the names. You can use the program @code{doschk} to test for this. Some GNU programs were designed to limit themselves to file names of 14 characters or less, to avoid file name conflicts if they are read into older System V systems. Please preserve this feature in the existing GNU programs that have it, but there is no need to do this in new GNU programs. @code{doschk} also reports file names longer than 14 characters. @node System Portability @section Portability between System Types @cindex portability, between system types In the Unix world, ``portability'' refers to porting to different Unix versions. For a GNU program, this kind of portability is desirable, but not paramount. The primary purpose of GNU software is to run on top of the GNU kernel, compiled with the GNU C compiler, on various types of @sc{cpu}. So the kinds of portability that are absolutely necessary are quite limited. But it is important to support Linux-based GNU systems, since they are the form of GNU that is popular. Beyond that, it is good to support the other free operating systems (*BSD), and it is nice to support other Unix-like systems if you want to. Supporting a variety of Unix-like systems is desirable, although not paramount. It is usually not too hard, so you may as well do it. But you don't have to consider it an obligation, if it does turn out to be hard. @pindex autoconf The easiest way to achieve portability to most Unix-like systems is to use Autoconf. It's unlikely that your program needs to know more information about the host platform than Autoconf can provide, simply because most of the programs that need such knowledge have already been written. Avoid using the format of semi-internal data bases (e.g., directories) when there is a higher-level alternative (@code{readdir}). @cindex non-@sc{posix} systems, and portability As for systems that are not like Unix, such as MSDOS, Windows, VMS, MVS, and older Macintosh systems, supporting them is often a lot of work. When that is the case, it is better to spend your time adding features that will be useful on GNU and GNU/Linux, rather than on supporting other incompatible systems. If you do support Windows, please do not abbreviate it as ``win''. In hacker terminology, calling something a ``win'' is a form of praise. You're free to praise Microsoft Windows on your own if you want, but please don't do this in GNU packages. Instead of abbreviating ``Windows'' to ``win'', you can write it in full or abbreviate it to ``woe'' or ``w''. In GNU Emacs, for instance, we use @samp{w32} in file names of Windows-specific files, but the macro for Windows conditionals is called @code{WINDOWSNT}. It is a good idea to define the ``feature test macro'' @code{_GNU_SOURCE} when compiling your C files. When you compile on GNU or GNU/Linux, this will enable the declarations of GNU library extension functions, and that will usually give you a compiler error message if you define the same function names in some other way in your program. (You don't have to actually @emph{use} these functions, if you prefer to make the program more portable to other systems.) But whether or not you use these GNU extensions, you should avoid using their names for any other meanings. Doing so would make it hard to move your code into other GNU programs. @node CPU Portability @section Portability between @sc{cpu}s @cindex data types, and portability @cindex portability, and data types Even GNU systems will differ because of differences among @sc{cpu} types---for example, difference in byte ordering and alignment requirements. It is absolutely essential to handle these differences. However, don't make any effort to cater to the possibility that an @code{int} will be less than 32 bits. We don't support 16-bit machines in GNU. Similarly, don't make any effort to cater to the possibility that @code{long} will be smaller than predefined types like @code{size_t}. For example, the following code is ok: @example printf ("size = %lu\n", (unsigned long) sizeof array); printf ("diff = %ld\n", (long) (pointer2 - pointer1)); @end example 1989 Standard C requires this to work, and we know of only one counterexample: 64-bit programs on Microsoft Windows. We will leave it to those who want to port GNU programs to that environment to figure out how to do it. Predefined file-size types like @code{off_t} are an exception: they are longer than @code{long} on many platforms, so code like the above won't work with them. One way to print an @code{off_t} value portably is to print its digits yourself, one by one. Don't assume that the address of an @code{int} object is also the address of its least-significant byte. This is false on big-endian machines. Thus, don't make the following mistake: @example int c; @dots{} while ((c = getchar ()) != EOF) write (file_descriptor, &c, 1); @end example @noindent Instead, use @code{unsigned char} as follows. (The @code{unsigned} is for portability to unusual systems where @code{char} is signed and where there is integer overflow checking.) @example int c; while ((c = getchar ()) != EOF) @{ unsigned char u = c; write (file_descriptor, &u, 1); @} @end example It used to be ok to not worry about the difference between pointers and integers when passing arguments to functions. However, on most modern 64-bit machines pointers are wider than @code{int}. Conversely, integer types like @code{long long int} and @code{off_t} are wider than pointers on most modern 32-bit machines. Hence it's often better nowadays to use prototypes to define functions whose argument types are not trivial. In particular, if functions accept varying argument counts or types they should be declared using prototypes containing @samp{...} and defined using @file{stdarg.h}. For an example of this, please see the @uref{http://www.gnu.org/software/gnulib/, Gnulib} error module, which declares and defines the following function: @example /* Print a message with `fprintf (stderr, FORMAT, ...)'; if ERRNUM is nonzero, follow it with ": " and strerror (ERRNUM). If STATUS is nonzero, terminate the program with `exit (STATUS)'. */ void error (int status, int errnum, const char *format, ...); @end example A simple way to use the Gnulib error module is to obtain the two source files @file{error.c} and @file{error.h} from the Gnulib library source code repository at @uref{http://git.savannah.gnu.org/@/gitweb/@/?p=gnulib.git}. Here's a sample use: @example #include "error.h" #include <errno.h> #include <stdio.h> char *program_name = "myprogram"; FILE * xfopen (char const *name) @{ FILE *fp = fopen (name, "r"); if (! fp) error (1, errno, "cannot read %s", name); return fp; @} @end example @cindex casting pointers to integers Avoid casting pointers to integers if you can. Such casts greatly reduce portability, and in most programs they are easy to avoid. In the cases where casting pointers to integers is essential---such as, a Lisp interpreter which stores type information as well as an address in one word---you'll have to make explicit provisions to handle different word sizes. You will also need to make provision for systems in which the normal range of addresses you can get from @code{malloc} starts far away from zero. @node System Functions @section Calling System Functions @cindex library functions, and portability @cindex portability, and library functions C implementations differ substantially. Standard C reduces but does not eliminate the incompatibilities; meanwhile, many GNU packages still support pre-standard compilers because this is not hard to do. This chapter gives recommendations for how to use the more-or-less standard C library functions to avoid unnecessary loss of portability. @itemize @bullet @item Don't use the return value of @code{sprintf}. It returns the number of characters written on some systems, but not on all systems. @item Be aware that @code{vfprintf} is not always available. @item @code{main} should be declared to return type @code{int}. It should terminate either by calling @code{exit} or by returning the integer status code; make sure it cannot ever return an undefined value. @cindex declaration for system functions @item Don't declare system functions explicitly. Almost any declaration for a system function is wrong on some system. To minimize conflicts, leave it to the system header files to declare system functions. If the headers don't declare a function, let it remain undeclared. While it may seem unclean to use a function without declaring it, in practice this works fine for most system library functions on the systems where this really happens; thus, the disadvantage is only theoretical. By contrast, actual declarations have frequently caused actual conflicts. @item If you must declare a system function, don't specify the argument types. Use an old-style declaration, not a Standard C prototype. The more you specify about the function, the more likely a conflict. @item In particular, don't unconditionally declare @code{malloc} or @code{realloc}. Most GNU programs use those functions just once, in functions conventionally named @code{xmalloc} and @code{xrealloc}. These functions call @code{malloc} and @code{realloc}, respectively, and check the results. Because @code{xmalloc} and @code{xrealloc} are defined in your program, you can declare them in other files without any risk of type conflict. On most systems, @code{int} is the same length as a pointer; thus, the calls to @code{malloc} and @code{realloc} work fine. For the few exceptional systems (mostly 64-bit machines), you can use @strong{conditionalized} declarations of @code{malloc} and @code{realloc}---or put these declarations in configuration files specific to those systems. @cindex string library functions @item The string functions require special treatment. Some Unix systems have a header file @file{string.h}; others have @file{strings.h}. Neither file name is portable. There are two things you can do: use Autoconf to figure out which file to include, or don't include either file. @item If you don't include either strings file, you can't get declarations for the string functions from the header file in the usual way. That causes less of a problem than you might think. The newer standard string functions should be avoided anyway because many systems still don't support them. The string functions you can use are these: @example strcpy strncpy strcat strncat strlen strcmp strncmp strchr strrchr @end example The copy and concatenate functions work fine without a declaration as long as you don't use their values. Using their values without a declaration fails on systems where the width of a pointer differs from the width of @code{int}, and perhaps in other cases. It is trivial to avoid using their values, so do that. The compare functions and @code{strlen} work fine without a declaration on most systems, possibly all the ones that GNU software runs on. You may find it necessary to declare them @strong{conditionally} on a few systems. The search functions must be declared to return @code{char *}. Luckily, there is no variation in the data type they return. But there is variation in their names. Some systems give these functions the names @code{index} and @code{rindex}; other systems use the names @code{strchr} and @code{strrchr}. Some systems support both pairs of names, but neither pair works on all systems. You should pick a single pair of names and use it throughout your program. (Nowadays, it is better to choose @code{strchr} and @code{strrchr} for new programs, since those are the standard names.) Declare both of those names as functions returning @code{char *}. On systems which don't support those names, define them as macros in terms of the other pair. For example, here is what to put at the beginning of your file (or in a header) if you want to use the names @code{strchr} and @code{strrchr} throughout: @example #ifndef HAVE_STRCHR #define strchr index #endif #ifndef HAVE_STRRCHR #define strrchr rindex #endif char *strchr (); char *strrchr (); @end example @end itemize Here we assume that @code{HAVE_STRCHR} and @code{HAVE_STRRCHR} are macros defined in systems where the corresponding functions exist. One way to get them properly defined is to use Autoconf. @node Internationalization @section Internationalization @cindex internationalization @pindex gettext GNU has a library called GNU gettext that makes it easy to translate the messages in a program into various languages. You should use this library in every program. Use English for the messages as they appear in the program, and let gettext provide the way to translate them into other languages. Using GNU gettext involves putting a call to the @code{gettext} macro around each string that might need translation---like this: @example printf (gettext ("Processing file `%s'...")); @end example @noindent This permits GNU gettext to replace the string @code{"Processing file `%s'..."} with a translated version. Once a program uses gettext, please make a point of writing calls to @code{gettext} when you add new strings that call for translation. Using GNU gettext in a package involves specifying a @dfn{text domain name} for the package. The text domain name is used to separate the translations for this package from the translations for other packages. Normally, the text domain name should be the same as the name of the package---for example, @samp{coreutils} for the GNU core utilities. @cindex message text, and internationalization To enable gettext to work well, avoid writing code that makes assumptions about the structure of words or sentences. When you want the precise text of a sentence to vary depending on the data, use two or more alternative string constants each containing a complete sentences, rather than inserting conditionalized words or phrases into a single sentence framework. Here is an example of what not to do: @smallexample printf ("%s is full", capacity > 5000000 ? "disk" : "floppy disk"); @end smallexample If you apply gettext to all strings, like this, @smallexample printf (gettext ("%s is full"), capacity > 5000000 ? gettext ("disk") : gettext ("floppy disk")); @end smallexample @noindent the translator will hardly know that "disk" and "floppy disk" are meant to be substituted in the other string. Worse, in some languages (like French) the construction will not work: the translation of the word "full" depends on the gender of the first part of the sentence; it happens to be not the same for "disk" as for "floppy disk". Complete sentences can be translated without problems: @example printf (capacity > 5000000 ? gettext ("disk is full") : gettext ("floppy disk is full")); @end example A similar problem appears at the level of sentence structure with this code: @example printf ("# Implicit rule search has%s been done.\n", f->tried_implicit ? "" : " not"); @end example @noindent Adding @code{gettext} calls to this code cannot give correct results for all languages, because negation in some languages requires adding words at more than one place in the sentence. By contrast, adding @code{gettext} calls does the job straightforwardly if the code starts out like this: @example printf (f->tried_implicit ? "# Implicit rule search has been done.\n", : "# Implicit rule search has not been done.\n"); @end example Another example is this one: @example printf ("%d file%s processed", nfiles, nfiles != 1 ? "s" : ""); @end example @noindent The problem with this example is that it assumes that plurals are made by adding `s'. If you apply gettext to the format string, like this, @example printf (gettext ("%d file%s processed"), nfiles, nfiles != 1 ? "s" : ""); @end example @noindent the message can use different words, but it will still be forced to use `s' for the plural. Here is a better way, with gettext being applied to the two strings independently: @example printf ((nfiles != 1 ? gettext ("%d files processed") : gettext ("%d file processed")), nfiles); @end example @noindent But this still doesn't work for languages like Polish, which has three plural forms: one for nfiles == 1, one for nfiles == 2, 3, 4, 22, 23, 24, ... and one for the rest. The GNU @code{ngettext} function solves this problem: @example printf (ngettext ("%d files processed", "%d file processed", nfiles), nfiles); @end example @node Character Set @section Character Set @cindex character set @cindex encodings @cindex ASCII characters @cindex non-ASCII characters Sticking to the ASCII character set (plain text, 7-bit characters) is preferred in GNU source code comments, text documents, and other contexts, unless there is good reason to do something else because of the application domain. For example, if source code deals with the French Revolutionary calendar, it is OK if its literal strings contain accented characters in month names like ``Flor@'eal''. Also, it is OK to use non-ASCII characters to represent proper names of contributors in change logs (@pxref{Change Logs}). If you need to use non-ASCII characters, you should normally stick with one encoding, as one cannot in general mix encodings reliably. @node Quote Characters @section Quote Characters @cindex quote characters @cindex locale-specific quote characters @cindex left quote @cindex grave accent In the C locale, GNU programs should stick to plain ASCII for quotation characters in messages to users: preferably 0x60 (@samp{`}) for left quotes and 0x27 (@samp{'}) for right quotes. It is ok, but not required, to use locale-specific quotes in other locales. The @uref{http://www.gnu.org/software/gnulib/, Gnulib} @code{quote} and @code{quotearg} modules provide a reasonably straightforward way to support locale-specific quote characters, as well as taking care of other issues, such as quoting a filename that itself contains a quote character. See the Gnulib documentation for usage details. In any case, the documentation for your program should clearly specify how it does quoting, if different than the preferred method of @samp{`} and @samp{'}. This is especially important if the output of your program is ever likely to be parsed by another program. Quotation characters are a difficult area in the computing world at this time: there are no true left or right quote characters in Latin1; the @samp{`} character we use was standardized there as a grave accent. Moreover, Latin1 is still not universally usable. Unicode contains the unambiguous quote characters required, and its common encoding UTF-8 is upward compatible with Latin1. However, Unicode and UTF-8 are not universally well-supported, either. This may change over the next few years, and then we will revisit this. @node Mmap @section Mmap @findex mmap Don't assume that @code{mmap} either works on all files or fails for all files. It may work on some files and fail on others. The proper way to use @code{mmap} is to try it on the specific file for which you want to use it---and if @code{mmap} doesn't work, fall back on doing the job in another way using @code{read} and @code{write}. The reason this precaution is needed is that the GNU kernel (the HURD) provides a user-extensible file system, in which there can be many different kinds of ``ordinary files.'' Many of them support @code{mmap}, but some do not. It is important to make programs handle all these kinds of files. @node Documentation @chapter Documenting Programs @cindex documentation A GNU program should ideally come with full free documentation, adequate for both reference and tutorial purposes. If the package can be programmed or extended, the documentation should cover programming or extending it, as well as just using it. @menu * GNU Manuals:: Writing proper manuals. * Doc Strings and Manuals:: Compiling doc strings doesn't make a manual. * Manual Structure Details:: Specific structure conventions. * License for Manuals:: Writing the distribution terms for a manual. * Manual Credits:: Giving credit to documentation contributors. * Printed Manuals:: Mentioning the printed manual. * NEWS File:: NEWS files supplement manuals. * Change Logs:: Recording changes. * Man Pages:: Man pages are secondary. * Reading other Manuals:: How far you can go in learning from other manuals. @end menu @node GNU Manuals @section GNU Manuals The preferred document format for the GNU system is the Texinfo formatting language. Every GNU package should (ideally) have documentation in Texinfo both for reference and for learners. Texinfo makes it possible to produce a good quality formatted book, using @TeX{}, and to generate an Info file. It is also possible to generate HTML output from Texinfo source. See the Texinfo manual, either the hardcopy, or the on-line version available through @code{info} or the Emacs Info subsystem (@kbd{C-h i}). Nowadays some other formats such as Docbook and Sgmltexi can be converted automatically into Texinfo. It is ok to produce the Texinfo documentation by conversion this way, as long as it gives good results. Make sure your manual is clear to a reader who knows nothing about the topic and reads it straight through. This means covering basic topics at the beginning, and advanced topics only later. This also means defining every specialized term when it is first used. Programmers tend to carry over the structure of the program as the structure for its documentation. But this structure is not necessarily good for explaining how to use the program; it may be irrelevant and confusing for a user. Instead, the right way to structure documentation is according to the concepts and questions that a user will have in mind when reading it. This principle applies at every level, from the lowest (ordering sentences in a paragraph) to the highest (ordering of chapter topics within the manual). Sometimes this structure of ideas matches the structure of the implementation of the software being documented---but often they are different. An important part of learning to write good documentation is to learn to notice when you have unthinkingly structured the documentation like the implementation, stop yourself, and look for better alternatives. For example, each program in the GNU system probably ought to be documented in one manual; but this does not mean each program should have its own manual. That would be following the structure of the implementation, rather than the structure that helps the user understand. Instead, each manual should cover a coherent @emph{topic}. For example, instead of a manual for @code{diff} and a manual for @code{diff3}, we have one manual for ``comparison of files'' which covers both of those programs, as well as @code{cmp}. By documenting these programs together, we can make the whole subject clearer. The manual which discusses a program should certainly document all of the program's command-line options and all of its commands. It should give examples of their use. But don't organize the manual as a list of features. Instead, organize it logically, by subtopics. Address the questions that a user will ask when thinking about the job that the program does. Don't just tell the reader what each feature can do---say what jobs it is good for, and show how to use it for those jobs. Explain what is recommended usage, and what kinds of usage users should avoid. In general, a GNU manual should serve both as tutorial and reference. It should be set up for convenient access to each topic through Info, and for reading straight through (appendixes aside). A GNU manual should give a good introduction to a beginner reading through from the start, and should also provide all the details that hackers want. The Bison manual is a good example of this---please take a look at it to see what we mean. That is not as hard as it first sounds. Arrange each chapter as a logical breakdown of its topic, but order the sections, and write their text, so that reading the chapter straight through makes sense. Do likewise when structuring the book into chapters, and when structuring a section into paragraphs. The watchword is, @emph{at each point, address the most fundamental and important issue raised by the preceding text.} If necessary, add extra chapters at the beginning of the manual which are purely tutorial and cover the basics of the subject. These provide the framework for a beginner to understand the rest of the manual. The Bison manual provides a good example of how to do this. To serve as a reference, a manual should have an Index that list all the functions, variables, options, and important concepts that are part of the program. One combined Index should do for a short manual, but sometimes for a complex package it is better to use multiple indices. The Texinfo manual includes advice on preparing good index entries, see @ref{Index Entries, , Making Index Entries, texinfo, GNU Texinfo}, and see @ref{Indexing Commands, , Defining the Entries of an Index, texinfo, GNU Texinfo}. Don't use Unix man pages as a model for how to write GNU documentation; most of them are terse, badly structured, and give inadequate explanation of the underlying concepts. (There are, of course, some exceptions.) Also, Unix man pages use a particular format which is different from what we use in GNU manuals. Please include an email address in the manual for where to report bugs @emph{in the text of the manual}. Please do not use the term ``pathname'' that is used in Unix documentation; use ``file name'' (two words) instead. We use the term ``path'' only for search paths, which are lists of directory names. Please do not use the term ``illegal'' to refer to erroneous input to a computer program. Please use ``invalid'' for this, and reserve the term ``illegal'' for activities prohibited by law. Please do not write @samp{()} after a function name just to indicate it is a function. @code{foo ()} is not a function, it is a function call with no arguments. @node Doc Strings and Manuals @section Doc Strings and Manuals Some programming systems, such as Emacs, provide a documentation string for each function, command or variable. You may be tempted to write a reference manual by compiling the documentation strings and writing a little additional text to go around them---but you must not do it. That approach is a fundamental mistake. The text of well-written documentation strings will be entirely wrong for a manual. A documentation string needs to stand alone---when it appears on the screen, there will be no other text to introduce or explain it. Meanwhile, it can be rather informal in style. The text describing a function or variable in a manual must not stand alone; it appears in the context of a section or subsection. Other text at the beginning of the section should explain some of the concepts, and should often make some general points that apply to several functions or variables. The previous descriptions of functions and variables in the section will also have given information about the topic. A description written to stand alone would repeat some of that information; this redundancy looks bad. Meanwhile, the informality that is acceptable in a documentation string is totally unacceptable in a manual. The only good way to use documentation strings in writing a good manual is to use them as a source of information for writing good text. @node Manual Structure Details @section Manual Structure Details @cindex manual structure The title page of the manual should state the version of the programs or packages documented in the manual. The Top node of the manual should also contain this information. If the manual is changing more frequently than or independent of the program, also state a version number for the manual in both of these places. Each program documented in the manual should have a node named @samp{@var{program} Invocation} or @samp{Invoking @var{program}}. This node (together with its subnodes, if any) should describe the program's command line arguments and how to run it (the sort of information people would look for in a man page). Start with an @samp{@@example} containing a template for all the options and arguments that the program uses. Alternatively, put a menu item in some menu whose item name fits one of the above patterns. This identifies the node which that item points to as the node for this purpose, regardless of the node's actual name. The @samp{--usage} feature of the Info reader looks for such a node or menu item in order to find the relevant text, so it is essential for every Texinfo file to have one. If one manual describes several programs, it should have such a node for each program described in the manual. @node License for Manuals @section License for Manuals @cindex license for manuals Please use the GNU Free Documentation License for all GNU manuals that are more than a few pages long. Likewise for a collection of short documents---you only need one copy of the GNU FDL for the whole collection. For a single short document, you can use a very permissive non-copyleft license, to avoid taking up space with a long license. See @uref{http://www.gnu.org/copyleft/fdl-howto.html} for more explanation of how to employ the GFDL. Note that it is not obligatory to include a copy of the GNU GPL or GNU LGPL in a manual whose license is neither the GPL nor the LGPL. It can be a good idea to include the program's license in a large manual; in a short manual, whose size would be increased considerably by including the program's license, it is probably better not to include it. @node Manual Credits @section Manual Credits @cindex credits for manuals Please credit the principal human writers of the manual as the authors, on the title page of the manual. If a company sponsored the work, thank the company in a suitable place in the manual, but do not cite the company as an author. @node Printed Manuals @section Printed Manuals The FSF publishes some GNU manuals in printed form. To encourage sales of these manuals, the on-line versions of the manual should mention at the very start that the printed manual is available and should point at information for getting it---for instance, with a link to the page @url{http://www.gnu.org/order/order.html}. This should not be included in the printed manual, though, because there it is redundant. It is also useful to explain in the on-line forms of the manual how the user can print out the manual from the sources. @node NEWS File @section The NEWS File @cindex @file{NEWS} file In addition to its manual, the package should have a file named @file{NEWS} which contains a list of user-visible changes worth mentioning. In each new release, add items to the front of the file and identify the version they pertain to. Don't discard old items; leave them in the file after the newer items. This way, a user upgrading from any previous version can see what is new. If the @file{NEWS} file gets very long, move some of the older items into a file named @file{ONEWS} and put a note at the end referring the user to that file. @node Change Logs @section Change Logs @cindex change logs Keep a change log to describe all the changes made to program source files. The purpose of this is so that people investigating bugs in the future will know about the changes that might have introduced the bug. Often a new bug can be found by looking at what was recently changed. More importantly, change logs can help you eliminate conceptual inconsistencies between different parts of a program, by giving you a history of how the conflicting concepts arose and who they came from. @menu * Change Log Concepts:: * Style of Change Logs:: * Simple Changes:: * Conditional Changes:: * Indicating the Part Changed:: @end menu @node Change Log Concepts @subsection Change Log Concepts You can think of the change log as a conceptual ``undo list'' which explains how earlier versions were different from the current version. People can see the current version; they don't need the change log to tell them what is in it. What they want from a change log is a clear explanation of how the earlier version differed. The change log file is normally called @file{ChangeLog} and covers an entire directory. Each directory can have its own change log, or a directory can use the change log of its parent directory---it's up to you. Another alternative is to record change log information with a version control system such as RCS or CVS. This can be converted automatically to a @file{ChangeLog} file using @code{rcs2log}; in Emacs, the command @kbd{C-x v a} (@code{vc-update-change-log}) does the job. There's no need to describe the full purpose of the changes or how they work together. However, sometimes it is useful to write one line to describe the overall purpose of a change or a batch of changes. If you think that a change calls for explanation, you're probably right. Please do explain it---but please put the full explanation in comments in the code, where people will see it whenever they see the code. For example, ``New function'' is enough for the change log when you add a function, because there should be a comment before the function definition to explain what it does. In the past, we recommended not mentioning changes in non-software files (manuals, help files, etc.) in change logs. However, we've been advised that it is a good idea to include them, for the sake of copyright records. The easiest way to add an entry to @file{ChangeLog} is with the Emacs command @kbd{M-x add-change-log-entry}. An entry should have an asterisk, the name of the changed file, and then in parentheses the name of the changed functions, variables or whatever, followed by a colon. Then describe the changes you made to that function or variable. @node Style of Change Logs @subsection Style of Change Logs @cindex change logs, style Here are some simple examples of change log entries, starting with the header line that says who made the change and when it was installed, followed by descriptions of specific changes. (These examples are drawn from Emacs and GCC.) @example 1998-08-17 Richard Stallman <rms@@gnu.org> * register.el (insert-register): Return nil. (jump-to-register): Likewise. * sort.el (sort-subr): Return nil. * tex-mode.el (tex-bibtex-file, tex-file, tex-region): Restart the tex shell if process is gone or stopped. (tex-shell-running): New function. * expr.c (store_one_arg): Round size up for move_block_to_reg. (expand_call): Round up when emitting USE insns. * stmt.c (assign_parms): Round size up for move_block_from_reg. @end example It's important to name the changed function or variable in full. Don't abbreviate function or variable names, and don't combine them. Subsequent maintainers will often search for a function name to find all the change log entries that pertain to it; if you abbreviate the name, they won't find it when they search. For example, some people are tempted to abbreviate groups of function names by writing @samp{* register.el (@{insert,jump-to@}-register)}; this is not a good idea, since searching for @code{jump-to-register} or @code{insert-register} would not find that entry. Separate unrelated change log entries with blank lines. When two entries represent parts of the same change, so that they work together, then don't put blank lines between them. Then you can omit the file name and the asterisk when successive entries are in the same file. Break long lists of function names by closing continued lines with @samp{)}, rather than @samp{,}, and opening the continuation with @samp{(} as in this example: @example * keyboard.c (menu_bar_items, tool_bar_items) (Fexecute_extended_command): Deal with `keymap' property. @end example When you install someone else's changes, put the contributor's name in the change log entry rather than in the text of the entry. In other words, write this: @example 2002-07-14 John Doe <jdoe@@gnu.org> * sewing.c: Make it sew. @end example @noindent rather than this: @example 2002-07-14 Usual Maintainer <usual@@gnu.org> * sewing.c: Make it sew. Patch by jdoe@@gnu.org. @end example As for the date, that should be the date you applied the change. @node Simple Changes @subsection Simple Changes Certain simple kinds of changes don't need much detail in the change log. When you change the calling sequence of a function in a simple fashion, and you change all the callers of the function to use the new calling sequence, there is no need to make individual entries for all the callers that you changed. Just write in the entry for the function being called, ``All callers changed''---like this: @example * keyboard.c (Fcommand_execute): New arg SPECIAL. All callers changed. @end example When you change just comments or doc strings, it is enough to write an entry for the file, without mentioning the functions. Just ``Doc fixes'' is enough for the change log. There's no technical need to make change log entries for documentation files. This is because documentation is not susceptible to bugs that are hard to fix. Documentation does not consist of parts that must interact in a precisely engineered fashion. To correct an error, you need not know the history of the erroneous passage; it is enough to compare what the documentation says with the way the program actually works. However, you should keep change logs for documentation files when the project gets copyright assignments from its contributors, so as to make the records of authorship more accurate. @node Conditional Changes @subsection Conditional Changes @cindex conditional changes, and change logs @cindex change logs, conditional changes C programs often contain compile-time @code{#if} conditionals. Many changes are conditional; sometimes you add a new definition which is entirely contained in a conditional. It is very useful to indicate in the change log the conditions for which the change applies. Our convention for indicating conditional changes is to use square brackets around the name of the condition. Here is a simple example, describing a change which is conditional but does not have a function or entity name associated with it: @example * xterm.c [SOLARIS2]: Include string.h. @end example Here is an entry describing a new definition which is entirely conditional. This new definition for the macro @code{FRAME_WINDOW_P} is used only when @code{HAVE_X_WINDOWS} is defined: @example * frame.h [HAVE_X_WINDOWS] (FRAME_WINDOW_P): Macro defined. @end example Here is an entry for a change within the function @code{init_display}, whose definition as a whole is unconditional, but the changes themselves are contained in a @samp{#ifdef HAVE_LIBNCURSES} conditional: @example * dispnew.c (init_display) [HAVE_LIBNCURSES]: If X, call tgetent. @end example Here is an entry for a change that takes affect only when a certain macro is @emph{not} defined: @example (gethostname) [!HAVE_SOCKETS]: Replace with winsock version. @end example @node Indicating the Part Changed @subsection Indicating the Part Changed Indicate the part of a function which changed by using angle brackets enclosing an indication of what the changed part does. Here is an entry for a change in the part of the function @code{sh-while-getopts} that deals with @code{sh} commands: @example * progmodes/sh-script.el (sh-while-getopts) <sh>: Handle case that user-specified option string is empty. @end example @node Man Pages @section Man Pages @cindex man pages In the GNU project, man pages are secondary. It is not necessary or expected for every GNU program to have a man page, but some of them do. It's your choice whether to include a man page in your program. When you make this decision, consider that supporting a man page requires continual effort each time the program is changed. The time you spend on the man page is time taken away from more useful work. For a simple program which changes little, updating the man page may be a small job. Then there is little reason not to include a man page, if you have one. For a large program that changes a great deal, updating a man page may be a substantial burden. If a user offers to donate a man page, you may find this gift costly to accept. It may be better to refuse the man page unless the same person agrees to take full responsibility for maintaining it---so that you can wash your hands of it entirely. If this volunteer later ceases to do the job, then don't feel obliged to pick it up yourself; it may be better to withdraw the man page from the distribution until someone else agrees to update it. When a program changes only a little, you may feel that the discrepancies are small enough that the man page remains useful without updating. If so, put a prominent note near the beginning of the man page explaining that you don't maintain it and that the Texinfo manual is more authoritative. The note should say how to access the Texinfo documentation. Be sure that man pages include a copyright statement and free license. The simple all-permissive license is appropriate for simple man pages (@pxref{License Notices for Other Files,,,maintain,Information for GNU Maintainers}). For long man pages, with enough explanation and documentation that they can be considered true manuals, use the GFDL (@pxref{License for Manuals}). Finally, the GNU help2man program (@uref{http://www.gnu.org/software/help2man/}) is one way to automate generation of a man page, in this case from @option{--help} output. This is sufficient in many cases. @node Reading other Manuals @section Reading other Manuals There may be non-free books or documentation files that describe the program you are documenting. It is ok to use these documents for reference, just as the author of a new algebra textbook can read other books on algebra. A large portion of any non-fiction book consists of facts, in this case facts about how a certain program works, and these facts are necessarily the same for everyone who writes about the subject. But be careful not to copy your outline structure, wording, tables or examples from preexisting non-free documentation. Copying from free documentation may be ok; please check with the FSF about the individual case. @node Managing Releases @chapter The Release Process @cindex releasing Making a release is more than just bundling up your source files in a tar file and putting it up for FTP. You should set up your software so that it can be configured to run on a variety of systems. Your Makefile should conform to the GNU standards described below, and your directory layout should also conform to the standards discussed below. Doing so makes it easy to include your package into the larger framework of all GNU software. @menu * Configuration:: How configuration of GNU packages should work. * Makefile Conventions:: Makefile conventions. * Releases:: Making releases @end menu @node Configuration @section How Configuration Should Work @cindex program configuration @pindex configure Each GNU distribution should come with a shell script named @code{configure}. This script is given arguments which describe the kind of machine and system you want to compile the program for. The @code{configure} script must record the configuration options so that they affect compilation. The description here is the specification of the interface for the @code{configure} script in GNU packages. Many packages implement it using GNU Autoconf (@pxref{Top,, Introduction, autoconf, Autoconf}) and/or GNU Automake (@pxref{Top,, Introduction, automake, Automake}), but you do not have to use these tools. You can implement it any way you like; for instance, by making @code{configure} be a wrapper around a completely different configuration system. Another way for the @code{configure} script to operate is to make a link from a standard name such as @file{config.h} to the proper configuration file for the chosen system. If you use this technique, the distribution should @emph{not} contain a file named @file{config.h}. This is so that people won't be able to build the program without configuring it first. Another thing that @code{configure} can do is to edit the Makefile. If you do this, the distribution should @emph{not} contain a file named @file{Makefile}. Instead, it should include a file @file{Makefile.in} which contains the input used for editing. Once again, this is so that people won't be able to build the program without configuring it first. If @code{configure} does write the @file{Makefile}, then @file{Makefile} should have a target named @file{Makefile} which causes @code{configure} to be rerun, setting up the same configuration that was set up last time. The files that @code{configure} reads should be listed as dependencies of @file{Makefile}. All the files which are output from the @code{configure} script should have comments at the beginning explaining that they were generated automatically using @code{configure}. This is so that users won't think of trying to edit them by hand. The @code{configure} script should write a file named @file{config.status} which describes which configuration options were specified when the program was last configured. This file should be a shell script which, if run, will recreate the same configuration. The @code{configure} script should accept an option of the form @samp{--srcdir=@var{dirname}} to specify the directory where sources are found (if it is not the current directory). This makes it possible to build the program in a separate directory, so that the actual source directory is not modified. If the user does not specify @samp{--srcdir}, then @code{configure} should check both @file{.} and @file{..} to see if it can find the sources. If it finds the sources in one of these places, it should use them from there. Otherwise, it should report that it cannot find the sources, and should exit with nonzero status. Usually the easy way to support @samp{--srcdir} is by editing a definition of @code{VPATH} into the Makefile. Some rules may need to refer explicitly to the specified source directory. To make this possible, @code{configure} can add to the Makefile a variable named @code{srcdir} whose value is precisely the specified directory. In addition, the @samp{configure} script should take options corresponding to most of the standard directory variables (@pxref{Directory Variables}). Here is the list: @example --prefix --exec-prefix --bindir --sbindir --libexecdir --sysconfdir --sharedstatedir --localstatedir --libdir --includedir --oldincludedir --datarootdir --datadir --infodir --localedir --mandir --docdir --htmldir --dvidir --pdfdir --psdir @end example The @code{configure} script should also take an argument which specifies the type of system to build the program for. This argument should look like this: @example @var{cpu}-@var{company}-@var{system} @end example For example, an Athlon-based GNU/Linux system might be @samp{i686-pc-linux-gnu}. The @code{configure} script needs to be able to decode all plausible alternatives for how to describe a machine. Thus, @samp{athlon-pc-gnu/linux} would be a valid alias. There is a shell script called @uref{http://git.savannah.gnu.org/@/gitweb/@/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD, @file{config.sub}} that you can use as a subroutine to validate system types and canonicalize aliases. The @code{configure} script should also take the option @option{--build=@var{buildtype}}, which should be equivalent to a plain @var{buildtype} argument. For example, @samp{configure --build=i686-pc-linux-gnu} is equivalent to @samp{configure i686-pc-linux-gnu}. When the build type is not specified by an option or argument, the @code{configure} script should normally guess it using the shell script @uref{http://git.savannah.gnu.org/@/gitweb/@/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD, @file{config.guess}}. @cindex optional features, configure-time Other options are permitted to specify in more detail the software or hardware present on the machine, to include or exclude optional parts of the package, or to adjust the name of some tools or arguments to them: @table @samp @item --enable-@var{feature}@r{[}=@var{parameter}@r{]} Configure the package to build and install an optional user-level facility called @var{feature}. This allows users to choose which optional features to include. Giving an optional @var{parameter} of @samp{no} should omit @var{feature}, if it is built by default. No @samp{--enable} option should @strong{ever} cause one feature to replace another. No @samp{--enable} option should ever substitute one useful behavior for another useful behavior. The only proper use for @samp{--enable} is for questions of whether to build part of the program or exclude it. @item --with-@var{package} @c @r{[}=@var{parameter}@r{]} The package @var{package} will be installed, so configure this package to work with @var{package}. @c Giving an optional @var{parameter} of @c @samp{no} should omit @var{package}, if it is used by default. Possible values of @var{package} include @samp{gnu-as} (or @samp{gas}), @samp{gnu-ld}, @samp{gnu-libc}, @samp{gdb}, @samp{x}, and @samp{x-toolkit}. Do not use a @samp{--with} option to specify the file name to use to find certain files. That is outside the scope of what @samp{--with} options are for. @item @var{variable}=@var{value} Set the value of the variable @var{variable} to @var{value}. This is used to override the default values of commands or arguments in the build process. For example, the user could issue @samp{configure CFLAGS=-g CXXFLAGS=-g} to build with debugging information and without the default optimization. Specifying variables as arguments to @code{configure}, like this: @example ./configure CC=gcc @end example is preferable to setting them in environment variables: @example CC=gcc ./configure @end example as it helps to recreate the same configuration later with @file{config.status}. However, both methods should be supported. @end table All @code{configure} scripts should accept all of the ``detail'' options and the variable settings, whether or not they make any difference to the particular package at hand. In particular, they should accept any option that starts with @samp{--with-} or @samp{--enable-}. This is so users will be able to configure an entire GNU source tree at once with a single set of options. You will note that the categories @samp{--with-} and @samp{--enable-} are narrow: they @strong{do not} provide a place for any sort of option you might think of. That is deliberate. We want to limit the possible configuration options in GNU software. We do not want GNU programs to have idiosyncratic configuration options. Packages that perform part of the compilation process may support cross-compilation. In such a case, the host and target machines for the program may be different. The @code{configure} script should normally treat the specified type of system as both the host and the target, thus producing a program which works for the same type of machine that it runs on. To compile a program to run on a host type that differs from the build type, use the configure option @option{--host=@var{hosttype}}, where @var{hosttype} uses the same syntax as @var{buildtype}. The host type normally defaults to the build type. To configure a cross-compiler, cross-assembler, or what have you, you should specify a target different from the host, using the configure option @samp{--target=@var{targettype}}. The syntax for @var{targettype} is the same as for the host type. So the command would look like this: @example ./configure --host=@var{hosttype} --target=@var{targettype} @end example The target type normally defaults to the host type. Programs for which cross-operation is not meaningful need not accept the @samp{--target} option, because configuring an entire operating system for cross-operation is not a meaningful operation. Some programs have ways of configuring themselves automatically. If your program is set up to do this, your @code{configure} script can simply ignore most of its arguments. @comment The makefile standards are in a separate file that is also @comment included by make.texinfo. Done by roland@gnu.ai.mit.edu on 1/6/93. @comment For this document, turn chapters into sections, etc. @lowersections @include make-stds.texi @raisesections @node Releases @section Making Releases @cindex packaging You should identify each release with a pair of version numbers, a major version and a minor. We have no objection to using more than two numbers, but it is very unlikely that you really need them. Package the distribution of @code{Foo version 69.96} up in a gzipped tar file with the name @file{foo-69.96.tar.gz}. It should unpack into a subdirectory named @file{foo-69.96}. Building and installing the program should never modify any of the files contained in the distribution. This means that all the files that form part of the program in any way must be classified into @dfn{source files} and @dfn{non-source files}. Source files are written by humans and never changed automatically; non-source files are produced from source files by programs under the control of the Makefile. @cindex @file{README} file The distribution should contain a file named @file{README} which gives the name of the package, and a general description of what it does. It is also good to explain the purpose of each of the first-level subdirectories in the package, if there are any. The @file{README} file should either state the version number of the package, or refer to where in the package it can be found. The @file{README} file should refer to the file @file{INSTALL}, which should contain an explanation of the installation procedure. The @file{README} file should also refer to the file which contains the copying conditions. The GNU GPL, if used, should be in a file called @file{COPYING}. If the GNU LGPL is used, it should be in a file called @file{COPYING.LESSER}. Naturally, all the source files must be in the distribution. It is okay to include non-source files in the distribution, provided they are up-to-date and machine-independent, so that building the distribution normally will never modify them. We commonly include non-source files produced by Bison, @code{lex}, @TeX{}, and @code{makeinfo}; this helps avoid unnecessary dependencies between our distributions, so that users can install whichever packages they want to install. Non-source files that might actually be modified by building and installing the program should @strong{never} be included in the distribution. So if you do distribute non-source files, always make sure they are up to date when you make a new distribution. Make sure that all the files in the distribution are world-readable, and that directories are world-readable and world-searchable (octal mode 755). We used to recommend that all directories in the distribution also be world-writable (octal mode 777), because ancient versions of @code{tar} would otherwise not cope when extracting the archive as an unprivileged user. That can easily lead to security issues when creating the archive, however, so now we recommend against that. Don't include any symbolic links in the distribution itself. If the tar file contains symbolic links, then people cannot even unpack it on systems that don't support symbolic links. Also, don't use multiple names for one file in different directories, because certain file systems cannot handle this and that prevents unpacking the distribution. Try to make sure that all the file names will be unique on MS-DOS. A name on MS-DOS consists of up to 8 characters, optionally followed by a period and up to three characters. MS-DOS will truncate extra characters both before and after the period. Thus, @file{foobarhacker.c} and @file{foobarhacker.o} are not ambiguous; they are truncated to @file{foobarha.c} and @file{foobarha.o}, which are distinct. @cindex @file{texinfo.tex}, in a distribution Include in your distribution a copy of the @file{texinfo.tex} you used to test print any @file{*.texinfo} or @file{*.texi} files. Likewise, if your program uses small GNU software packages like regex, getopt, obstack, or termcap, include them in the distribution file. Leaving them out would make the distribution file a little smaller at the expense of possible inconvenience to a user who doesn't know what other files to get. @node References @chapter References to Non-Free Software and Documentation @cindex references to non-free material A GNU program should not recommend, promote, or grant legitimacy to the use of any non-free program. Proprietary software is a social and ethical problem, and our aim is to put an end to that problem. We can't stop some people from writing proprietary programs, or stop other people from using them, but we can and should refuse to advertise them to new potential customers, or to give the public the idea that their existence is ethical. The GNU definition of free software is found on the GNU web site at @url{http://www.gnu.org/@/philosophy/@/free-sw.html}, and the definition of free documentation is found at @url{http://www.gnu.org/@/philosophy/@/free-doc.html}. The terms ``free'' and ``non-free'', used in this document, refer to those definitions. A list of important licenses and whether they qualify as free is in @url{http://www.gnu.org/@/licenses/@/license-list.html}. If it is not clear whether a license qualifies as free, please ask the GNU Project by writing to @email{licensing@@gnu.org}. We will answer, and if the license is an important one, we will add it to the list. When a non-free program or system is well known, you can mention it in passing---that is harmless, since users who might want to use it probably already know about it. For instance, it is fine to explain how to build your package on top of some widely used non-free operating system, or how to use it together with some widely used non-free program. However, you should give only the necessary information to help those who already use the non-free program to use your program with it---don't give, or refer to, any further information about the proprietary program, and don't imply that the proprietary program enhances your program, or that its existence is in any way a good thing. The goal should be that people already using the proprietary program will get the advice they need about how to use your free program with it, while people who don't already use the proprietary program will not see anything likely to lead them to take an interest in it. If a non-free program or system is obscure in your program's domain, your program should not mention or support it at all, since doing so would tend to popularize the non-free program more than it popularizes your program. (You cannot hope to find many additional users for your program among the users of Foobar, if the existence of Foobar is not generally known among people who might want to use your program.) Sometimes a program is free software in itself but depends on a non-free platform in order to run. For instance, many Java programs depend on some non-free Java libraries. To recommend or promote such a program is to promote the other programs it needs. This is why we are careful about listing Java programs in the Free Software Directory: we don't want to promote the non-free Java libraries. We hope this particular problem with Java will be gone by and by, as we replace the remaining non-free standard Java libraries with free software, but the general principle will remain the same: don't recommend, promote or legitimize programs that depend on non-free software to run. Some free programs strongly encourage the use of non-free software. A typical example is @command{mplayer}. It is free software in itself, and the free code can handle some kinds of files. However, @command{mplayer} recommends use of non-free codecs for other kinds of files, and users that install @command{mplayer} are very likely to install those codecs along with it. To recommend @command{mplayer} is, in effect, to promote use of the non-free codecs. Thus, you should not recommend programs that strongly encourage the use of non-free software. This is why we do not list @command{mplayer} in the Free Software Directory. A GNU package should not refer the user to any non-free documentation for free software. Free documentation that can be included in free operating systems is essential for completing the GNU system, or any free operating system, so encouraging it is a priority; to recommend use of documentation that we are not allowed to include undermines the impetus for the community to produce documentation that we can include. So GNU packages should never recommend non-free documentation. By contrast, it is ok to refer to journal articles and textbooks in the comments of a program for explanation of how it functions, even though they are non-free. This is because we don't include such things in the GNU system even they are free---they are outside the scope of what a software distribution needs to include. Referring to a web site that describes or recommends a non-free program is promoting that program, so please do not make links (or mention by name) web sites that contain such material. This policy is relevant particularly for the web pages for a GNU package. Following links from nearly any web site can lead eventually to non-free software; this is inherent in the nature of the web. So it makes no sense to criticize a site for having such links. As long as the site does not itself recommend a non-free program, there is no need to consider the question of the sites that it links to for other reasons. Thus, for example, you should not refer to AT&T's web site if that recommends AT&T's non-free software packages; you should not refer to a site that links to AT&T's site presenting it as a place to get some non-free program, because that link recommends and legitimizes the non-free program. However, that a site contains a link to AT&T's web site for some other purpose (such as long-distance telephone service) is not an objection against it. @node GNU Free Documentation License @appendix GNU Free Documentation License @cindex FDL, GNU Free Documentation License @include fdl.texi @node Index @unnumbered Index @printindex cp @bye Local variables: eval: (add-hook 'write-file-hooks 'time-stamp) time-stamp-start: "@set lastupdate " time-stamp-end: "$" time-stamp-format: "%:b %:d, %:y" compile-command: "cd work.s && make" End: ���������������������������������gnu-standards-2010.03.11/work.m/��������������������������������������������������������������������0000775�0000000�0000000�00000000000�11351271455�0016072�5����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������gnu-standards-2010.03.11/work.m/.cvsignore����������������������������������������������������������0000664�0000000�0000000�00000000007�11351271455�0020067�0����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������[a-z]* �������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������gnu-standards-2010.03.11/work.m/GNUmakefile���������������������������������������������������������0000664�0000000�0000000�00000003734�11351271455�0020153�0����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������# Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc. # # Copying and distribution of this file, with or without modification, # are permitted in any medium without royalty provided the copyright # notice and this notice are preserved. # # To use these targets, first do (one time only): # - ln -s ../*.texi . # - copy gendocs.sh and gendocs_template from texinfo/util here. # - then try make a, then make b, then make c # - if all goes well, see info at end for updating the web. # - also update gnulib/doc. # check that makeinfo is happy. a: makeinfo maintain # build everything. b: gendocs.sh maintain "Information for maintainers of GNU software" # fix cross-manual xrefs. # be nice to do this more cleanly later, but needs Texinfo config file, etc. c: # new-style gendocs.sh perl -pi -e 's,href="(texinfo|emacs).html,href="/software/\1/manual/\1/\1.html,g' manual/maintain.html perl -pi -e 's,href="\.\./(texinfo|emacs)/,href="/software/\1/manual/\1/html_node/,g' manual/html_node/*.html # # new-style gendocs.sh, but special location. perl -pi -e 's,href="(standards).html,href="/prep/\1/\1.html,g' manual/maintain.html perl -pi -e 's,href="\.\./(standards)/,href="/prep/\1/html_node/,g' manual/html_node/*.html # # old-style (and not updated for ages) perl -pi -e 's,href="(cvs).html,href="/software/\1/manual/html_mono/\1.html,g' manual/maintain.html perl -pi -e 's,href="\.\./(cvs)/,href="/software/\1/manual/\1/html_node/,g' manual/html_node/*.html # # elisp perl -pi -e 's,href="elisp.html,href="/software/emacs/manual/html_mono/elisp.html,g' manual/maintain.html perl -pi -e 's,href="\.\./elisp/,href="/software/emacs/manual/html_node/elisp/,g' manual/html_node/*.html # gzip -9f <manual/maintain.html >manual/maintain.html.gz cd manual/html_node && tar czf ../maintain.html_node.tar.gz -- *.html # cd manual && tar cjf ../m.tbz . # then unpack m.tbz in a cvs checkout of www/prep/maintain, cvs add any # new files, cvs remove any old ones, and cvs commit everything. ������������������������������������gnu-standards-2010.03.11/work.s/��������������������������������������������������������������������0000775�0000000�0000000�00000000000�11351271455�0016100�5����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������gnu-standards-2010.03.11/work.s/.cvsignore����������������������������������������������������������0000664�0000000�0000000�00000000007�11351271455�0020075�0����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������[a-z]* �������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������gnu-standards-2010.03.11/work.s/GNUmakefile���������������������������������������������������������0000664�0000000�0000000�00000003524�11351271455�0020156�0����������������������������������������������������������������������������������������������������ustar�00root����������������������������root����������������������������0000000�0000000������������������������������������������������������������������������������������������������������������������������������������������������������������������������# Copyright (C) 2006, 2007, 2008, 2009 Free Software Foundation, Inc. # # Copying and distribution of this file, with or without modification, # are permitted in any medium without royalty provided the copyright # notice and this notice are preserved. # # To use these targets, first do (one time only): # - ln -s ../*.texi . # - copy gendocs.sh and gendocs_template from texinfo/util here. # - then try make a, then make b, then make c # - if all goes well, see info at end for updating the web. # - also update gnulib/doc. # check that makeinfo is happy. (Best error messages, etc.) a: makeinfo standards # build everything. b: gendocs.sh standards "GNU coding standards" # fix cross-manual xrefs. # be nice to do this more cleanly later, but needs Texinfo config file, etc. c: # # new-style gendocs.sh, but special location. perl -pi -e 's,href="(maintain).html,href="/prep/\1/\1.html,g' manual/standards.html perl -pi -e 's,href="\.\./(maintain)/,href="/prep/\1/html_node/,g' manual/html_node/*.html # # new-style gendocs.sh perl -pi -e 's,href="\.\./texinfo/,href="/software/texinfo/manual/texinfo/html_node/,g' manual/html_node/*.html perl -pi -e 's,href="\.\./autoconf/,href="/software/autoconf/manual/html_node/,g' manual/html_node/*.html # # makeinfo bug in toc creation of standalone html (for --version/help nodes). perl -pi -e 's,#_00,#g_t_00,' manual/standards.html # gzip -9f <manual/standards.html >manual/standards.html.gz cd manual/html_node && tar czf ../standards.html_node.tar.gz -- *.html # (cd manual && tar cjf ../s.tbz .) # then unpack s.tbz in a cvs checkout of www/prep/standards, cvs add any # new files, cvs remove any old ones, and cvs commit everything. # # to copy to a local checkout ($gw). # cd manual && for f in `find -type f`; do \ # cmp -s $$f $$gw/prep/standards/$$f \ # || \cp -f $$f $$gw/prep/standards/$$f -v; done 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