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8 Debian GNU/Linux Policy Manual.
9 Copyright (C)1996,1997,1998 Ian Jackson and Christian Schwarz;
10 released under the terms of the GNU
11 General Public License, version 2 or (at your option) any later.
12 Initial version 1996, Ian Jackson, ijackson@gnu.ai.mit.edu
13 Revised November 27, 1996, David A. Morris, bweaver@debian.org
14 New sections March 15, 1997, Christian Schwarz, schwarz@debian.org
15 Reworked/Restructured April-July 1997, Christian Schwarz, schwarz@debian.org
16 Maintainer since 1997, Christian Schwarz, schwarz@debian.org
17 Christoph Lameter contributed the "Web Standard"
18 The debian-policy mailing list has taken responsibility for the
19 contents of this document since September 1998, with the package
20 maintainers responsible for packaging administrivia only.
25 <title>Debian Policy Manual</title>
27 <name>Ian Jackson </name>
28 <email>ijackson@gnu.ai.mit.edu</email>
31 <name>Christian Schwarz</name>
32 <email>schwarz@debian.org</email>
35 <name>revised: David A. Morris</name>
36 <email>bweaver@debian.org</email>
39 <name>The Debian Policy mailing List</name>
40 <email>debian-policy@lists.debian.org</email>
42 <version>version &version;, &date;</version>
45 This manual describes the policy requirements for the Debian
46 GNU/Linux distribution. This includes the structure and
47 contents of the Debian archive and several design issues of the
48 operating system, as well as technical requirements that each
49 package must satisfy to be included in the distribution. The
50 policy package itself is maintained by a group of maintainers
51 that have no editorial powers. At the moment, the list of
55 <p>Julian Gilbey <email>jdg@debian.org</email></p>
58 <p>Manoj Srivastava <email>srivasta@debian.org</email></p>
66 Copyright ©1996,1997,1998 Ian Jackson
67 and Christian Schwarz.
70 This manual is free software; you may redistribute it and/or
71 modify it under the terms of the GNU General Public License
72 as published by the Free Software Foundation; either version
73 2, or (at your option) any later version.
77 This is distributed in the hope that it will be useful, but
78 <em>without any warranty</em>; without even the implied
79 warranty of merchantability or fitness for a particular
80 purpose. See the GNU General Public License for more
85 A copy of the GNU General Public License is available as
86 <tt>/usr/share/common-licenses/GPL</tt> in the Debian GNU/Linux
87 distribution or on the World Wide Web at
88 <url id="http://www.gnu.org/copyleft/gpl.html"
89 name="The GNU General Public Licence">. You can also
90 obtain it by writing to the Free Software Foundation, Inc.,
91 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
99 <heading>About this manual</heading>
101 <heading>Scope</heading>
103 This manual describes the policy requirements for the Debian
104 GNU/Linux distribution. This includes the structure and
105 contents of the Debian archive and several design issues of the
106 operating system, as well as technical requirements that
107 each package must satisfy to be included in the
113 This manual also describes Debian policy as it relates to
114 creating Debian packages. It is not a tutorial on how to build
115 packages, nor is it exhaustive where it comes to describing
116 the behavior of the packaging system. Instead, this manual
117 attempts to define the interface to the package management
118 system that the developers have to be conversant with.
121 Informally, the criteria used for inclusion is that the
122 material meet one of the following requirements:
124 <tag>Standard interfaces</tag>
127 The material presented represents an interface to
128 the packaging system that is mandated for use, and
129 is used by, a significant number of packages, and
130 therefore should not be changed without peer
131 review. Package maintainers can then rely on this
132 interfaces not changing, and the package
133 management software authors need to ensure
134 compatibility with these interface
135 definitions. (Control file and changelog file
136 formats are examples.)
139 <tag>Chosen Convention</tag>
142 If there are a number of technically viable choices
143 that can be made, but one needs to select one of
144 these options for inter-operability. The version
145 number format is one example.
149 Please note that these are not mutually exclusive;
150 selected conventions often become parts of standard
157 The footnotes present in this manual are
158 merely informative, and are not part of Debian policy itself.
163 In this manual, the words <em>must</em>, <em>should</em> and
164 <em>may</em>, and the adjectives <em>required</em>,
165 <em>recommended</em> and <em>optional</em>, are used to
166 distinguish the significance of the various guidelines in
167 this policy document. Packages that do not conform to the
168 guidelines denoted by <em>must</em> (or <em>required</em>)
169 will generally not be considered acceptable for the Debian
170 distribution. Non-conformance with guidelines denoted by
171 <em>should</em> (or <em>recommended</em>) will generally be
172 considered a bug, but will not necessarily render a package
173 unsuitable for distribution. Guidelines denoted by
174 <em>may</em> (or <em>optional</em>) are truly optional and
175 adherence is left to the maintainer's discretion.
178 These classifications are roughly equivalent to the bug
179 severities <em>serious</em> (for <em>must</em> or
180 <em>required</em> directive violations), <em>minor</em>,
181 <em>normal</em> or <em>important</em>
182 (for <em>should</em> or <em>recommended</em> directive
183 violations) and <em>wishlist</em> (for <em>optional</em>
185 <p>Compare RFC 2119. Note, however, that these words are
186 used in a different way in this document.</p>
190 Much of the information presented in this manual will be
191 useful even when building a package which is to be
192 distributed in some other way or is intended for local use
197 <heading>New versions of this document</heading>
199 The current version of this document is always accessible
200 from the Debian FTP server <ftpsite>ftp.debian.org</ftpsite>
202 <ftppath>/debian/doc/package-developer/policy.txt.gz</ftppath>
203 (also available from the same directory are several other
204 formats: <tt>policy.html.tar.gz</tt>, <tt>policy.pdf.gz</tt>
205 and <tt>policy.ps.gz</tt>) or from the <url
206 id="http://www.debian.org/doc/debian-policy/" name="Debian
207 Policy Manual"> webpage.</p>
210 In addition, this manual is distributed via the Debian package
211 <tt>debian-policy</tt>.
215 The <tt>debian-policy</tt> package also includes the file
216 <tt>upgrading-checklist.txt</tt> which indicates policy
217 changes between versions of this document.
221 <heading>Feedback</heading>
224 As the Debian GNU/Linux system is continuously evolving this
228 While the authors of this document have tried hard to avoid
229 typos and other errors, these do still occur. If you discover
230 an error in this manual or if you want to give any
231 comments, suggestions, or criticisms please send an email to
232 the Debian Policy List,
233 <email>debian-policy@lists.debian.org</email>, or submit a
234 bug report against the <tt>debian-policy</tt> package.
239 <heading>The Debian Archive</heading>
241 The Debian GNU/Linux system is maintained and distributed as a
242 collection of <em>packages</em>. Since there are so many of
243 them (currently well over 6000), they are split into
244 <em>sections</em> and given <em>priorities</em> to simplify
245 the handling of them.
248 The effort of the Debian project is to build a free operating
249 system, but not every package we want to make accessible is
250 <em>free</em> in our sense (see the Debian Free Software
251 Guidelines, below), or may be imported/exported without
252 restrictions. Thus, the archive is split into the sections
253 <em>main</em>, <em>non-free</em>, <em>contrib</em>,
254 <em>non-US/main</em>, <em>non-US/non-free</em>, and
255 <em>non-US/contrib</em>. The sections are explained in detail
260 The <em>main</em> and the <em>non-US/main</em> sections
261 together form the <em>Debian GNU/Linux distribution</em>.
265 Packages in the other sections are not considered to be part
266 of the Debian distribution, although we support their use and
267 provide infrastructure for them (such as our bug-tracking
268 system and mailing lists). This Debian Policy Manual applies
269 to these packages as well.</p>
271 <sect id="pkgcopyright">
272 <heading>Package copyright and sections</heading>
274 The aims of this section are:
276 <list compact="compact">
278 <p>to allow us to make as much software available as we
282 <p>to allow us to encourage everyone to write free
286 <p>to allow us to make it easy for people to produce
287 CD-ROMs of our system without violating any licenses,
288 import/export restrictions, or any other laws.</p>
293 <heading>The Debian Free Software Guidelines</heading>
295 The Debian Free Software Guidelines (DFSG) form our
296 definition of `free software'. These are:
298 <tag>Free Redistribution
302 The license of a Debian component may not restrict any
303 party from selling or giving away the software as a
304 component of an aggregate software distribution
305 containing programs from several different
306 sources. The license may not require a royalty or
307 other fee for such sale.
314 The program must include source code, and must allow
315 distribution in source code as well as compiled form.
322 The license must allow modifications and derived
323 works, and must allow them to be distributed under the
324 same terms as the license of the original software.
327 <tag>Integrity of The Author's Source Code
331 The license may restrict source-code from being
332 distributed in modified form <em>only</em> if the
333 license allows the distribution of ``patch files''
334 with the source code for the purpose of modifying the
335 program at build time. The license must explicitly
336 permit distribution of software built from modified
337 source code. The license may require derived works to
338 carry a different name or version number from the
339 original software. (This is a compromise. The Debian
340 Project encourages all authors to not restrict any
341 files, source or binary, from being modified.)
344 <tag>No Discrimination Against Persons or Groups
348 The license must not discriminate against any person
352 <tag>No Discrimination Against Fields of Endeavor
356 The license must not restrict anyone from making use
357 of the program in a specific field of endeavor. For
358 example, it may not restrict the program from being
359 used in a business, or from being used for genetic
363 <tag>Distribution of License
367 The rights attached to the program must apply to all
368 to whom the program is redistributed without the need
369 for execution of an additional license by those
373 <tag>License Must Not Be Specific to Debian
377 The rights attached to the program must not depend on
378 the program's being part of a Debian system. If the
379 program is extracted from Debian and used or
380 distributed without Debian but otherwise within the
381 terms of the program's license, all parties to whom
382 the program is redistributed must have the same
383 rights as those that are granted in conjunction with
387 <tag>License Must Not Contaminate Other Software
391 The license must not place restrictions on other
392 software that is distributed along with the licensed
393 software. For example, the license must not insist
394 that all other programs distributed on the same medium
395 must be free software.
398 <tag>Example Licenses
402 The ``GPL,'' ``BSD,'' and ``Artistic'' licenses are
403 examples of licenses that we consider <em>free</em>.
410 <heading>The main section</heading>
412 Every package in <em>main</em> and <em>non-US/main</em>
413 must comply with the DFSG (Debian Free Software
417 In addition, the packages in <em>main</em>
418 <list compact="compact">
421 must not require a package outside of <em>main</em>
422 for compilation or execution (thus, the package must
423 not declare a "Depends", "Recommends", or
424 "Build-Depends" relationship on a non-<em>main</em>
430 must not be so buggy that we refuse to support them,
436 must meet all policy requirements presented in this
443 Similarly, the packages in <em>non-US/main</em>
444 <list compact="compact">
447 must not require a package outside of <em>main</em>
448 or <em>non-US/main</em> for compilation or
454 must not be so buggy that we refuse to support them,
459 must meet all policy requirements presented in this
467 <heading>The contrib section</heading>
469 Every package in <em>contrib</em> and
470 <em>non-US/contrib</em> must comply with the DFSG.
474 In addition, the packages in <em>contrib</em> and
475 <em>non-US/contrib</em>
476 <list compact="compact">
479 must not be so buggy that we refuse to support them,
485 must meet all policy requirements presented in this
493 Furthermore, packages in <em>contrib</em> must not require
494 a package in a <em>non-US</em> section for compilation or
499 Examples of packages which would be included in
500 <em>contrib</em> or <em>non-US/contrib</em> are:
501 <list compact="compact">
504 free packages which require <em>contrib</em>,
505 <em>non-free</em> packages or packages which are not
506 in our archive at all for compilation or execution,
512 wrapper packages or other sorts of free accessories for
520 <heading>The non-free section</heading>
522 Packages must be placed in <em>non-free</em> or
523 <em>non-US/non-free</em> if they are not compliant with
524 the DFSG or are encumbered by patents or other legal
525 issues that make their distribution problematic.
528 In addition, the packages in <em>non-free</em> and
529 <em>non-US/non-free</em>
530 <list compact="compact">
533 must not be so buggy that we refuse to support them,
539 must meet all policy requirements presented in this
540 manual that it is possible for them to meet.
543 It is possible that there are policy
544 requirements which the package is unable to
545 meet, for example, if the source is
546 unavailable. These situations will need to be
547 handled on a case-by-case basis.
557 <heading>The non-US sections</heading>
559 Some programs with cryptographic program code need to be
560 stored on the <em>non-US</em> server because of United
561 States export restrictions. Such programs must be
562 distributed in the appropriate <em>non-US</em> section,
563 either <em>non-US/main</em>, <em>non-US/contrib</em> or
564 <em>non-US/non-free</em>.
567 This applies only to packages which contain cryptographic
568 code. A package containing a program with an interface to
569 a cryptographic program or a program that's dynamically
570 linked against a cryptographic library should not be
571 distributed via the <em>non-US</em> server if it is
572 capable of running without the cryptographic library or
577 <heading>Further copyright considerations</heading>
579 Every package must be accompanied by a verbatim copy of
580 its copyright and distribution license in the file
581 <tt>/usr/share/doc/<em><package-name></em>/copyright</tt>
582 (see <ref id="copyrightfile"> for further details).
585 We reserve the right to restrict files from being included
586 anywhere in our archives if
587 <list compact="compact">
590 their use or distribution would break a law,
595 there is an ethical conflict in their distribution or
601 we would have to sign a license for them, or
606 their distribution would conflict with other project
614 Programs whose authors encourage the user to make
615 donations are fine for the main distribution, provided
616 that the authors do not claim that not donating is
617 immoral, unethical, illegal or something similar; in such
618 a case they must go in <em>non-free</em>.</p>
621 Packages whose copyright permission notices (or patent
622 problems) do not even allow redistribution of binaries
623 only, and where no special permission has been obtained,
624 must not be placed on the Debian FTP site and its mirrors
628 Note that under international copyright law (this applies
629 in the United States, too), <em>no</em> distribution or
630 modification of a work is allowed without an explicit
631 notice saying so. Therefore a program without a copyright
632 notice <em>is</em> copyrighted and you may not do anything
633 to it without risking being sued! Likewise if a program
634 has a copyright notice but no statement saying what is
635 permitted then nothing is permitted.</p>
638 Many authors are unaware of the problems that restrictive
639 copyrights (or lack of copyright notices) can cause for
640 the users of their supposedly-free software. It is often
641 worthwhile contacting such authors diplomatically to ask
642 them to modify their license terms. However, this can be a
643 politically difficult thing to do and you should ask for
644 advice on the <tt>debian-legal</tt> mailing list first, as
649 When in doubt about a copyright, send mail to
650 <email>debian-legal@lists.debian.org</email>. Be prepared
651 to provide us with the copyright statement. Software
652 covered by the GPL, public domain software and BSD-like
653 copyrights are safe; be wary of the phrases `commercial
654 use prohibited' and `distribution restricted'.
658 <heading>Subsections</heading>
661 The packages in the sections <em>main</em>,
662 <em>contrib</em> and <em>non-free</em> are grouped further
663 into <em>subsections</em> to simplify handling.
667 The section and subsection for each package should be
668 specified in the package's <tt>Section</tt> control
669 record. However, the maintainer of the Debian archive
670 may override this selection to ensure the consistency of
671 the Debian distribution. The <tt>Section</tt> field
672 should be of the form:
673 <list compact="compact">
676 <em>subsection</em> if the package is in the
677 <em>main</em> section,
682 <em>section/subsection</em> if the package is in
683 the <em>contrib</em> or <em>non-free</em> section,
689 <tt>non-US</tt>, <tt>non-US/contrib</tt> or
690 <tt>non-US/non-free</tt> if the package is in
691 <em>non-US/main</em>, <em>non-US/contrib</em> or
692 <em>non-US/non-free</em> respectively.
699 The Debian archive maintainers provide the authoritative
700 list of subsections. At present, they are:
701 <em>admin</em>, <em>base</em>, <em>comm</em>,
702 <em>contrib</em>, <em>devel</em>, <em>doc</em>,
703 <em>editors</em>, <em>electronics</em>, <em>games</em>,
704 <em>graphics</em>, <em>hamradio</em>,
705 <em>interpreters</em>, <em>libs</em>, <em>mail</em>,
706 <em>math</em>, <em>misc</em>, <em>net</em>, <em>news</em>,
707 <em>non-US</em>, <em>non-free</em>, <em>oldlibs</em>,
708 <em>otherosfs</em>, <em>science</em>, <em>shells</em>,
709 <em>sound</em>, <em>tex</em>, <em>text</em>,
710 <em>utils</em>, <em>web</em>, <em>x11</em>.
714 <heading>Priorities</heading>
717 Each package should have a <em>priority</em> value, which is
718 included in the package's <em>control record</em>. This
719 information is used by the Debian package management tools
720 to separate high-priority packages from less-important
724 The following <em>priority levels</em> are recognised by the
725 Debian package management tools.
727 <tag><tt>required</tt></tag>
730 Packages which are necessary for the proper
731 functioning of the system. You must not remove these
732 packages or your system may become totally broken and
733 you may not even be able to use <prgn>dpkg</prgn> to
734 put things back. Systems with only the
735 <tt>required</tt> packages are probably unusable, but
736 they do have enough functionality to allow the
737 sysadmin to boot and install more software.</p>
739 <tag><tt>important</tt></tag>
742 Important programs, including those which one would
743 expect to find on any Unix-like system. If the
744 expectation is that an experienced Unix person who
745 found it missing would say `What on earth is going on,
746 where is <prgn>foo</prgn>?', it must be an
747 <tt>important</tt> package.
750 This is an important criterion because we are
751 trying to produce, amongst other things, a free
755 Other packages without which the system will not run
756 well or be usable must also have priority
757 <tt>important</tt>. This does
758 <em>not</em> include Emacs, the X Window System, TeX
759 or any other large applications. The
760 <tt>important</tt> packages are just a bare minimum of
761 commonly-expected and necessary tools.</p>
763 <tag><tt>standard</tt></tag>
766 These packages provide a reasonably small but not too
767 limited character-mode system. This is what will be
768 installed by default if the user doesn't select anything
769 else. It doesn't include many large applications, but
770 it does include Emacs (this is more of a piece of
771 infrastructure than an application) and a reasonable
772 subset of TeX and LaTeX.</p>
774 <tag><tt>optional</tt></tag>
777 (In a sense everything that isn't required is
778 optional, but that's not what is meant here.) This is
779 all the software that you might reasonably want to
780 install if you didn't know what it was and don't have
781 specialized requirements. This is a much larger system
782 and includes the X Window System, a full TeX
783 distribution, and many applications. Note that
784 optional packages should not conflict with each other.
787 <tag><tt>extra</tt></tag>
790 This contains all packages that conflict with others
791 with required, important, standard or optional
792 priorities, or are only likely to be useful if you
793 already know what they are or have specialised
800 Packages must not depend on packages with lower priority
801 values (excluding build-time dependencies). In order to
802 ensure this, the priorities of one or more packages may need
808 <heading>Binary packages</heading>
811 The Debian GNU/Linux distribution is based on the Debian
812 package management system, called <prgn>dpkg</prgn>. Thus,
813 all packages in the Debian distribution must be provided
814 in the <tt>.deb</tt> file format.</p>
818 <heading>The package name</heading>
821 Every package must have a name that's unique within the Debian
825 Package names must consist of lower case letters (a-z),
826 digits (0-9), plus (+) and minus (-) signs, and periods
827 (.). They must be at least two characters long and must
828 contain at least one letter.
832 The package name is part of the file name of the
833 <tt>.deb</tt> file and is included in the control field
839 <heading>The maintainer of a package</heading>
841 Every package must have a Debian maintainer (the
842 maintainer may be one person or a group of people
843 reachable from a common email address, such as a mailing
844 list). The maintainer is responsible for ensuring that
845 the package is placed in the appropriate distributions.
849 The maintainer must be specified in the
850 <tt>Maintainer</tt> control field with their correct name
851 and a working email address. If one person maintains
852 several packages, he/she should try to avoid having
853 different forms of their name and email address in
854 the <tt>Maintainer</tt> fields of those packages.
858 If the maintainer of a package quits from the Debian
859 project, "Debian QA Group"
860 <email>packages@qa.debian.org</email> takes over the
861 maintainership of the package until someone else
862 volunteers for that task. These packages are called
863 <em>orphaned packages</em>.
866 The detailed procedure for doing this gracefully can
867 be found in the Debian Developer's Reference, either
868 in the <tt>developers-reference</tt> package, or on
869 the Debian FTP server
870 <ftpsite>ftp.debian.org</ftpsite> as
871 <ftppath>/debian/doc/package-developer/developers-reference.txt.gz</ftppath>
873 id="http://www.debian.org/doc/packaging-manuals/developers-reference/"
874 name="Debian Developer's Reference"> webpage.
882 <heading>The description of a package</heading>
885 Every Debian package must have an extended description
886 stored in the appropriate field of the control record.</p>
889 The description should be written so that it gives the
890 system administrator enough information to decide whether
891 to install the package. This description should not just
892 be copied verbatim from the program's documentation.
893 Instructions for configuring or using the package should
894 not be included -- that is what installation scripts,
895 manual pages, info files, etc., are for. Copyright
896 statements and other administrivia should not be included
897 either -- that is what the copyright file is for.</p>
902 <heading>Dependencies</heading>
905 Every package must specify the dependency information
906 about other packages that are required for the first to
910 For example, a dependency entry must be provided for any
911 shared libraries required by a dynamically-linked executable
912 binary in a package.</p>
915 Packages are not required to declare any dependencies they
916 have on other packages which are marked <tt>Essential</tt>
917 (see below), and should not do so unless they depend on a
918 particular version of that package.</p>
921 Sometimes, a package requires another package to be installed
922 <em>and</em> configured before it can be installed. In this
923 case, you must specify a <tt>Pre-Depends</tt> entry for
927 You should not specify a <tt>Pre-Depends</tt> entry for a
928 package before this has been discussed on the
929 <tt>debian-devel</tt> mailing list and a consensus about
930 doing that has been reached.</p></sect1>
934 <heading>Virtual packages</heading>
937 Sometimes, there are several packages which offer
938 more-or-less the same functionality. In this case, it's
939 useful to define a <em>virtual package</em> whose name
940 describes that common functionality. (The virtual
941 packages only exist logically, not physically--that's why
942 they are called <em>virtual</em>.) The packages with this
943 particular function will then <em>provide</em> the virtual
944 package. Thus, any other package requiring that function
945 can simply depend on the virtual package without having to
946 specify all possible packages individually.</p>
949 All packages should use virtual package names where
950 appropriate, and arrange to create new ones if necessary.
951 They should not use virtual package names (except privately,
952 amongst a cooperating group of packages) unless they have
953 been agreed upon and appear in the list of virtual package
957 The latest version of the authoritative list of virtual
958 package names can be found on
959 <ftpsite>ftp.debian.org</ftpsite> in
960 <ftppath>/debian/doc/package-developer/virtual-package-names-list.txt</ftppath>
961 or your local mirror. In addition, it is included in the
962 <tt>debian-policy</tt> package. The procedure for updating
963 the list is described at the top of the file.</p></sect1>
967 <heading>Base packages</heading>
970 The packages included in the <tt>base</tt> section have a
971 special function. They form a minimum subset of the Debian
972 GNU/Linux system that is installed before everything else
973 on a new system. Thus, only very few packages are allowed
974 to go into the <tt>base</tt> section to keep the required
975 disk usage very small.</p>
978 Most of these packages will have the priority value
979 <tt>required</tt> or at least <tt>important</tt>, and many
980 of them will be tagged <tt>essential</tt> (see below).</p>
983 You must not place any packages into the <tt>base</tt>
984 section before this has been discussed on the
985 <tt>debian-devel</tt> mailing list and a consensus about
986 doing that has been reached.</p></sect1>
990 <heading>Essential packages</heading>
993 Some packages are tagged <tt>essential</tt>. (They have
994 <tt>Essential: yes</tt> in their package control record.)
995 This flag is used for packages that are <em>essential</em>
999 Since these packages cannot be easily removed (one has to
1000 specify an extra <em>force option</em> to
1001 <prgn>dpkg</prgn> to do so), this flag must not be used
1002 unless absolutely necessary. A shared library package
1003 must not be tagged <tt>essential</tt>--dependencies will
1004 prevent its premature removal, and we need to be able to
1005 remove it when it has been superseded.
1009 Since dpkg will not prevent upgrading of other packages
1010 while an <tt>essential</tt> package is in an unconfigured
1011 state, all <tt>essential</tt> packages must supply all of
1012 their core functionality even when unconfigured. If the
1013 package cannot satisfy this requirement it must not be
1014 tagged as essential, and any packages depending on this
1015 package must instead have explicit dependency fields as
1020 You must not tag any packages <tt>essential</tt> before
1021 this has been discussed on the <tt>debian-devel</tt>
1022 mailing list and a consensus about doing that has been
1028 <heading>Maintainer scripts</heading>
1031 The package installation scripts should avoid producing
1032 output which it is unnecessary for the user to see and
1033 should rely on <prgn>dpkg</prgn> to stave off boredom on
1034 the part of a user installing many packages. This means,
1035 amongst other things, using the <tt>--quiet</tt> option on
1036 <prgn>install-info</prgn>.</p>
1039 Errors which occur during the execution of an installation
1040 script must be checked and the installation must not
1041 continue after an error.
1045 Note that in general <ref id="scripts"> applies to package
1046 maintainer scripts, too.
1050 You should not use <tt>dpkg-divert</tt> on a file
1051 belonging to another package without consulting the
1052 maintainer of that package first.
1055 All packages which supply an instance of a common command
1056 name (or, in general, filename) should generally use
1057 <prgn>update-alternatives</prgn>, so that they may be
1058 installed together. If <prgn>update-alternatives</prgn>
1059 is not used, then each package must use
1060 <var>Conflicts</var> to ensure that other packages are
1061 de-installed. (In this case, it may be appropriate to
1062 specify a conflict against earlier versions of something
1063 that previously did not use
1064 <prgn>update-alternatives</prgn> - this is an exception to
1065 the usual rule that versioned conflicts should be
1071 <heading>Prompting in maintainer scripts</heading>
1073 Package maintainer scripts may prompt the user if
1074 necessary. Prompting may be accomplished by hand, or by
1075 communicating with a program, such as
1076 <prgn>debconf</prgn>, which conforms to the Debian
1077 Configuration management specification, version 2 or
1078 higher. These are included in the
1079 <file>debconf_specification</file> files in the
1080 <package>debian-policy</package> package.
1081 You may also find this file on the FTP site
1082 <ftpsite>ftp.debian.org</ftpsite> in
1083 <ftppath>/debian/doc/package-developer/debconf_specification.txt.gz</ftppath>
1084 or on your local mirror.
1087 2.5% of Debian packages [see <url
1088 id="http://kitenet.net/programs/debconf/stats/">]
1089 currently use <package>debconf</package> to prompt
1090 the user at install time, and this number is growing
1091 daily. The benefits of using debconf are briefly
1093 id="http://kitenet.net/doc/debconf-doc/introduction.html">;
1094 they include preconfiguration, (mostly)
1095 noninteractive installation, elimination of
1096 redundant prompting, consistency of user interface,
1100 With this increasing number of packages using
1101 <package>debconf</package>, plus the existance of a
1102 nascent second implementation of the Debian
1103 configuration management system
1104 (<package>cdebconf</package>), and the stabalization
1105 of the protocol these things use, the time has
1106 finally come to reflect the use of these things in
1113 Packages which use the Debian Configuration management
1114 specification may contain an additional
1115 <file>config</file> script and a <file>templates</file>
1116 file in their control archive. The <prgn>config</prgn>
1117 script might be run before the <prgn>preinst</prgn>
1118 script, and before the package is unpacked or any of its
1119 dependancies or pre-dependancies are satisfied.
1120 Therefore it must work using only the tools present in
1121 <em>essential</em> packages.
1124 <package>Debconf</package> or another tool that
1125 implements the Debian Configuration management
1126 specification will also be installed, and any
1127 versioned dependencies on it will be satisfied
1128 before preconfiguration begins.
1134 Packages should try to minimize the amount of prompting
1135 they need to do, and they should ensure that the user
1136 will only ever be asked each question once. This means
1137 that packages should try to use appropriate shared
1138 configuration files (such as <tt>/etc/papersize</tt> and
1139 <tt>/etc/news/server</tt>), and shared
1140 <package>debconf</package> variables rather than each
1141 prompting for their own list of required pieces of
1146 It also means that an upgrade should not ask the same
1147 questions again, unless the user has used <tt>dpkg
1148 --purge</tt> to remove the package's configuration. The
1149 answers to configuration questions should be stored in an
1150 appropriate place in <tt>/etc</tt> so that the user can
1151 modify them, and how this has been done should be
1155 If a package has a vitally important piece of
1156 information to pass to the user (such as "don't run me
1157 as I am, you must edit the following configuration files
1158 first or you risk your system emitting badly-formatted
1159 messages"), it should display this in the
1160 <prgn>config</prgn> or <prgn>postinst</prgn> script and
1161 prompt the user to hit return to acknowledge the
1162 message. Copyright messages do not count as vitally
1163 important (they belong in
1164 <tt>/usr/share/doc/<var>package</var>/copyright</tt>);
1165 neither do instructions on how to use a program (these
1166 should be in on-line documentation, where all the users
1170 Any necessary prompting should almost always be confined
1171 to the <prgn>config</prgn> or <prgn>postinst</prgn>
1172 script. If it is done in the <prgn>postinst</prgn>, it
1173 should be protected with a conditional so that unnecessary
1174 prompting doesn't happen if a package's installation fails
1175 and the <prgn>postinst</prgn> is called with
1176 <tt>abort-upgrade</tt>, <tt>abort-remove</tt> or
1177 <tt>abort-deconfigure</tt>.</p>
1182 <heading>Source packages</heading>
1184 <sect1 id="standardsversion">
1185 <heading>Standards conformance</heading>
1188 In the source package's <tt>Standards-Version</tt> control
1189 field, you must specify the most recent version number of
1190 this policy document with which your package complies.
1191 The current version number is &version;.
1195 This information may be used to file bug reports
1196 automatically if your package becomes too much out of
1201 The version number has four components--major and minor
1202 version number and major and minor patch level. When the
1203 standards change in a way that requires every package to
1204 change the major number will be changed. Significant
1205 changes that will require work in many packages will be
1206 signaled by a change to the minor number. The major patch
1207 level will be changed for any change to the meaning of the
1208 standards, however small; the minor patch level will be
1209 changed when only cosmetic, typographical or other edits
1210 are made which neither change the meaning of the document
1211 nor affect the contents of packages.</p>
1214 Thus only the first three components of the policy version
1215 are significant in the <em>Standards-Version</em> control
1216 field, and so either these three components or the all
1217 four components may be specified.
1220 In the past, people specified the full version number
1221 in the Standards-Version field, for example `2.3.0.0'.
1222 Since minor patch-level changes don't introduce new
1223 policy, it was thought it would be better to relax
1224 policy and only require the first 3 components to be
1225 specified, in this example `2.3.0'. All four
1226 components may still be used if someone wishes to do
1233 You should regularly, and especially if your package has
1234 become out of date, check for the newest Policy Manual
1235 available and update your package, if necessary. When your
1236 package complies with the new standards you should update the
1237 <tt>Standards-Version</tt> source package field and
1241 See the file <tt>upgrading-checklist</tt> for
1242 information about policy which has changed between
1243 different versions of this document.
1251 <heading>Package relationships</heading>
1254 Source packages should specify which binary packages they
1255 require to be installed or not to be installed in order to
1256 build correctly. For example, if building a package
1257 requires a certain compiler, then the compiler should be
1258 specified as a build-time dependency.
1262 It is not necessary to explicitly specify build-time
1263 relationships on a minimal set of packages that are always
1264 needed to compile, link and put in a Debian package a
1265 standard "Hello World!" program written in C or C++. The
1266 required packages are called <em>build-essential</em>, and
1267 an informational list can be found in
1268 <tt>/usr/share/doc/build-essential/list</tt> (which is
1269 contained in the <tt>build-essential</tt>
1275 <p>This allows maintaining the list separately
1276 from the policy documents (the list does not
1277 need the kind of control that the policy
1283 Having a separate package allows one to install
1284 the build-essential packages on a machine, as
1285 well as allowing other packages such as task
1286 packages to require installation of the
1287 build-essential packages using the depends
1293 The separate package allows bug reports against
1294 the list to be categorized separately from
1295 the policy management process in the BTS.
1305 When specifying the set of build-time dependencies, one
1306 should list only those packages explicitly required by the
1307 build. It is not necessary to list packages which are
1308 required merely because some other package in the list of
1309 build-time dependencies depends on them.
1312 The reason for this is that dependencies change, and
1313 you should list all those packages, and <em>only</em>
1314 those packages that <em>you</em> need directly. What
1315 others need is their business. For example, if you
1316 only link against <tt>libimlib</tt>, you will need to
1317 build-depend on <package>libimlib2-dev</package> but
1318 not against any <tt>libjpeg*</tt> packages, even
1319 though <tt>libimlib2-dev</tt> currently depends on
1320 them: installation of <package>libimlib2-dev</package>
1321 will automatically ensure that all of its run-time
1322 dependencies are satisfied.
1328 If build-time dependencies are specified, it must be
1329 possible to build the package and produce working binaries
1330 on a system with only essential and build-essential
1331 packages installed and also those required to satisfy the
1332 build-time relationships (including any implied
1333 relationships). In particular, this means that version
1334 clauses should be used rigorously in build-time
1335 relationships so that one cannot produce bad or
1336 inconsistently configured packages when the relationships
1337 are properly satisfied.
1341 <heading>Changes to the upstream sources</heading>
1344 If changes to the source code are made that are not
1345 specific to the needs of the Debian system, they should be
1346 sent to the upstream authors in whatever form they prefer
1347 so as to be included in the upstream version of the
1351 If you need to configure the package differently for
1352 Debian or for Linux, and the upstream source doesn't
1353 provide a way to do so, you should add such configuration
1354 facilities (for example, a new <prgn>autoconf</prgn> test
1355 or <tt>#define</tt>) and send the patch to the upstream
1356 authors, with the default set to the way they originally
1357 had it. You can then easily override the default in your
1358 <tt>debian/rules</tt> or wherever is appropriate.</p>
1361 You should make sure that the <prgn>configure</prgn> utility
1362 detects the correct architecture specification string
1363 (refer to <ref id="arch-spec"> for details).</p>
1366 If you need to edit a <prgn>Makefile</prgn> where
1367 GNU-style <prgn>configure</prgn> scripts are used, you
1368 should edit the <tt>.in</tt> files rather than editing the
1369 <prgn>Makefile</prgn> directly. This allows the user to
1370 reconfigure the package if necessary. You should
1371 <em>not</em> configure the package and edit the generated
1372 <prgn>Makefile</prgn>! This makes it impossible for
1373 someone else to later reconfigure the package.</p></sect1>
1377 <heading>Documenting your changes</heading>
1380 You should document your changes and updates to the source
1381 package properly in the <tt>debian/changelog</tt> file. (Note
1382 that mistakes in changelogs are usually best rectified by
1383 making a new changelog entry rather than "rewriting history"
1384 by editing old changelog entries.)</p>
1387 In non-experimental packages you must use a format for
1388 <tt>debian/changelog</tt> which is supported by the most
1389 recent released version of <prgn>dpkg</prgn>.
1392 If you wish to use an alternative format, you may do
1393 so as long as you include a parser for it in your
1394 source package. The parser must have an API
1395 compatible with that expected by
1396 <prgn>dpkg-genchanges</prgn> and
1397 <prgn>dpkg-gencontrol</prgn>. If there is general
1398 interest in the new format, you should contact the
1399 <package>dpkg</package> maintainer to have the parser
1400 script for it included in the <prgn>dpkg</prgn>
1401 package. (You will need to agree that the parser and
1402 its manpage may be distributed under the GNU GPL, just
1403 as the rest of `dpkg' is.)
1411 <heading>Error trapping in makefiles</heading>
1414 When <prgn>make</prgn> invokes a command in a makefile
1415 (including your package's upstream makefiles and
1416 <tt>debian/rules</tt>), it does so using <tt>sh</tt>. This
1417 means that <tt>sh</tt>'s usual bad error handling
1418 properties apply: if you include a miniature script as one
1419 of the commands in your makefile you'll find that if you
1420 don't do anything about it then errors are not detected
1421 and <prgn>make</prgn> will blithely continue after
1425 Every time you put more than one shell command (this
1426 includes using a loop) in a makefile command you
1427 must make sure that errors are trapped. For
1428 simple compound commands, such as changing directory and
1429 then running a program, using <tt>&&</tt> rather
1430 than semicolon as a command separator is sufficient. For
1431 more complex commands including most loops and
1432 conditionals you should include a separate <tt>set -e</tt>
1433 command at the start of every makefile command that's
1434 actually one of these miniature shell scripts.</p></sect1>
1438 <heading>Obsolete constructs and libraries</heading>
1441 The include file <prgn><varargs.h></prgn> is
1442 provided to support end-users compiling very old software;
1443 the library <tt>libtermcap</tt> is provided to support the
1444 execution of software which has been linked against it
1445 (either old programs or those such as Netscape which are
1446 only available in binary form).</p>
1449 Debian packages should be patched to use
1450 <prgn><stdarg.h></prgn> and <tt>ncurses</tt>
1457 <chapt id="controlfields"><heading>Control files and their fields</heading>
1460 Many of the tools in the package management suite manipulate
1461 data represented in a common format, known as <em>control
1462 data</em>. The data is often stored in <em>control
1463 files</em>. Binary and source packages have control files,
1464 and the <tt>.changes</tt> files which control the installation
1465 of uploaded files are also in control file format.
1466 <prgn>Dpkg</prgn>'s internal databases are in a similar
1470 <sect><heading>Syntax of control files</heading>
1473 A control file consists of one or more paragraphs of fields.
1474 The paragraphs are separated by blank lines. Some control
1475 files allow only one paragraph; others allow several, in
1476 which case each paragraph usually refers to a different
1477 package. (For example, in source packages, the first
1478 paragraph refers to the source package, and later paragraphs
1479 refer to binary packages generated from the source.)
1483 Each paragraph consists of a series of data fields; each
1484 field consists of the field name, followed by a colon and
1485 then the data/value associated with that field. It ends at
1486 the end of the line. Horizontal whitespace (spaces and
1487 tabs) may occur immediately before or after the value and is
1488 ignored there; it is conventional to put a single space
1489 after the colon. For example, a field might be:
1493 the field name is <tt>Package</tt> and the field value
1498 Some fields' values may span several lines; in this case
1499 each continuation line <em>must</em> start with a space or
1500 tab. Any trailing spaces or tabs at the end of individual
1501 lines of a field value are ignored.
1505 Except where otherwise stated only a single line of data is
1506 allowed and whitespace is not significant in a field body.
1507 Whitespace must not appear inside names (of packages,
1508 architectures, files or anything else) or version numbers,
1509 or between the characters of multi-character version
1514 Field names are not case-sensitive, but it is usual to
1515 capitalize the field names using mixed case as shown below.
1519 Blank lines, or lines consisting only of spaces and tabs,
1520 are not allowed within field values or between fields - that
1521 would mean a new paragraph.
1526 <sect><heading>List of fields</heading>
1528 This list here is not supposed to be exhaustive. Most fields
1529 are dealt with elsewhere in this document.
1531 <sect1 id="f-Package"><heading><tt>Package</tt>
1535 The name of the binary package. Package names consist of
1536 the alphanumerics and <tt>+</tt> <tt>-</tt> <tt>.</tt>
1537 (plus, minus and full stop).
1541 They must be at least two characters long and must start
1542 with an alphanumeric character and not be all digits. The
1543 use of lowercase package names is strongly recommended
1544 unless the package you're building (or referring to, in
1545 other fields) is already using uppercase.</p>
1548 <sect1 id="f-Version"><heading><tt>Version</tt>
1552 This lists the source or binary package's version number -
1553 see <ref id="versions">.
1559 id="f-Standards-Version"><heading><tt>Standards-Version</tt>
1563 The most recent version of the standards (the policy
1564 manual and associated texts) with which the package
1565 complies. This is updated manually when editing the
1566 source package to conform to newer standards; it can
1567 sometimes be used to tell when a package needs attention.
1568 Its format is described above; see
1569 <ref id="standardsversion">.
1574 <sect1 id="f-Distribution"><heading><tt>Distribution</tt>
1578 In a <tt>.changes</tt> file or parsed changelog output
1579 this contains the (space-separated) name(s) of the
1580 distribution(s) where this version of the package should
1581 be installed. Valid distributions are determined by the
1582 archive maintainers.
1584 Current distribution names are:
1586 <tag><em>stable</em></tag>
1589 This is the current `released' version of Debian
1590 GNU/Linux. Once the distribution is
1591 <em>stable</em> only security fixes and other
1592 major bug fixes are allowed. When changes are
1593 made to this distribution, the release number is
1594 increased (for example: 2.2r1 becomes 2.2r2 then
1599 <tag><em>unstable</em></tag>
1602 This distribution value refers to the
1603 <em>developmental</em> part of the Debian
1604 distribution tree. New packages, new upstream
1605 versions of packages and bug fixes go into the
1606 <em>unstable</em> directory tree. Download from
1607 this distribution at your own risk.
1611 <tag><em>testing</em></tag>
1614 This distribution value refers to the
1615 <em>testing</em> part of the Debian distribution
1616 tree. It receives its packages from the
1617 unstable distribution after a short time lag to
1618 ensure that there are no major issues with the
1619 unstable packages. It is less prone to breakage
1620 than unstable, but still risky. It is not
1621 possible to upload packages directly to
1626 <tag><em>frozen</em></tag>
1629 From time to time, the <em>frozen</em>
1630 distribution enters a state of `code-freeze' in
1631 anticipation of release as a <em>stable</em>
1632 version. During this period of testing only
1633 fixes for existing or newly-discovered bugs will
1634 be allowed. The exact details of this stage are
1635 determined by the Release Manager.
1639 <tag><em>experimental</em></tag>
1642 The packages with this distribution value are
1643 deemed by their maintainers to be high
1644 risk. Oftentimes they represent early beta or
1645 developmental packages from various sources that
1646 the maintainers want people to try, but are not
1647 ready to be a part of the other parts of the
1648 Debian distribution tree. Download at your own
1654 You should list <em>all</em> distributions that the
1655 package should be installed into.
1664 <chapt id="versions"><heading>Version numbering</heading>
1667 Every package has a version number recorded in its
1668 <tt>Version</tt> control file field.
1672 The package management system imposes an ordering on version
1673 numbers, so that it can tell whether packages are being up- or
1674 downgraded and so that package system front end applications
1675 can tell whether a package it finds available is newer than
1676 the one installed on the system. The version number format
1677 has the most significant parts (as far as comparison is
1678 concerned) at the beginning.
1682 The version number format is:
1683 &lsqb<var>epoch</var><tt>:</tt>]<var>upstream_version</var>[<tt>-</tt><var>debian_revision</var>]
1687 The three components here are:
1689 <tag><var>epoch</var></tag>
1693 This is a single (generally small) unsigned integer. It
1694 may be omitted, in which case zero is assumed. If it is
1695 omitted then the <var>upstream_version</var> may not
1700 It is provided to allow mistakes in the version numbers
1701 of older versions of a package, and also a package's
1702 previous version numbering schemes, to be left behind.
1707 <tag><var>upstream_version</var></tag>
1711 This is the main part of the version number. It is
1712 usually the version number of the original (`upstream')
1713 package from which the <tt>.deb</tt> file has been made,
1714 if this is applicable. Usually this will be in the same
1715 format as that specified by the upstream author(s);
1716 however, it may need to be reformatted to fit into the
1717 package management system's format and comparison
1722 The comparison behavior of the package management system
1723 with respect to the <var>upstream_version</var> is
1724 described below. The <var>upstream_version</var>
1725 portion of the version number is mandatory.
1729 The <var>upstream_version</var> may contain only
1732 <p>Alphanumerics are <tt>A-Za-z0-9</tt> only.</p>
1734 and the characters <tt>.</tt> <tt>+</tt> <tt>-</tt>
1735 <tt>:</tt> (full stop, plus, hyphen, colon) and should
1736 start with a digit. If there is no
1737 <var>debian_revision</var> then hyphens are not allowed;
1738 if there is no <var>epoch</var> then colons are not
1742 <tag><var>debian_revision</var></tag>
1746 This part of the version number specifies the version of
1747 the Debian package based on the upstream version. It
1748 may contain only alphanumerics and the characters
1749 <tt>+</tt> and <tt>.</tt> (plus and full stop) and is
1750 compared in the same way as the
1751 <var>upstream_version</var> is.
1755 It is optional; if it isn't present then the
1756 <var>upstream_version</var> may not contain a hyphen.
1757 This format represents the case where a piece of
1758 software was written specifically to be turned into a
1759 Debian package, and so there is only one `debianization'
1760 of it and therefore no revision indication is required.
1764 It is conventional to restart the
1765 <var>debian_revision</var> at <tt>1</tt> each time the
1766 <var>upstream_version</var> is increased.
1770 The package management system will break the version
1771 number apart at the last hyphen in the string (if there
1772 is one) to determine the <var>upstream_version</var> and
1773 <var>debian_revision</var>. The absence of a
1774 <var>debian_revision</var> compares earlier than the
1775 presence of one (but note that the
1776 <var>debian_revision</var> is the least significant part
1777 of the version number).
1781 The <var>upstream_version</var> and <var>debian_revision</var>
1782 parts are compared by the package management system using the
1787 The strings are compared from left to right.
1791 First the initial part of each string consisting entirely of
1792 non-digit characters is determined. These two parts (one of
1793 which may be empty) are compared lexically. If a difference
1794 is found it is returned. The lexical comparison is a
1795 comparison of ASCII values modified so that all the letters
1796 sort earlier than all the non-letters.
1800 Then the initial part of the remainder of each string which
1801 consists entirely of digit characters is determined. The
1802 numerical values of these two parts are compared, and any
1803 difference found is returned as the result of the comparison.
1804 For these purposes an empty string (which can only occur at
1805 the end of one or both version strings being compared) counts
1810 These two steps (comparing and removing initial non-digit
1811 strings and initial digit strings) are repeated until a
1812 difference is found or both strings are exhausted.
1816 Note that the purpose of epochs is to allow us to leave behind
1817 mistakes in version numbering, and to cope with situations
1818 where the version numbering scheme changes. It is
1819 <em>not</em> intended to cope with version numbers containing
1820 strings of letters which the package management system cannot
1821 interpret (such as <tt>ALPHA</tt> or <tt>pre-</tt>), or with
1822 silly orderings (the author of this manual has heard of a
1823 package whose versions went <tt>1.1</tt>, <tt>1.2</tt>,
1824 <tt>1.3</tt>, <tt>1</tt>, <tt>2.1</tt>, <tt>2.2</tt>,
1825 <tt>2</tt> and so forth).
1829 If an upstream package has problematic version numbers they
1830 should be converted to a sane form for use in the
1831 <tt>Version</tt> field.
1835 <heading>Version numbers based on dates</heading>
1837 In general, Debian packages should use the same version
1838 numbers as the upstream sources.</p>
1841 However, in some cases where the upstream version number is
1842 based on a date (e.g., a development `snapshot' release) the
1843 package management system cannot handle these version
1844 numbers without epochs. For example, dpkg will consider
1845 `96May01' to be greater than `96Dec24'.</p>
1848 To prevent having to use epochs for every new upstream
1849 version, the version number should be changed to the
1850 following format in such cases: `19960501', `19961224'. It
1851 is up to the maintainer whether he/she wants to bother the
1852 upstream maintainer to change the version numbers upstream,
1856 Note that other version formats based on dates which are
1857 parsed correctly by the package management system should
1858 <em>not</em> be changed.</p>
1861 Native Debian packages (i.e., packages which have been
1862 written especially for Debian) whose version numbers include
1863 dates should always use the `YYYYMMDD' format.</p>
1867 <chapt id="miscellaneous"><heading>Packaging Considerations</heading>
1869 <sect id="timestamps"><heading>Time Stamps</heading>
1871 Maintainers should preserve the modification times of the
1872 upstream source files in a package, as far as is reasonably
1876 The rationale is that there is some information conveyed
1877 by knowing the age of the file, for example, you could
1878 recognize that some documentation is very old by looking
1879 at the modification time, so it would be nice if the
1880 modification time of the upstream source would be
1887 <sect id="debianrules"><heading><tt>debian/rules</tt> - the
1888 main building script</heading>
1891 This file must be an executable makefile, and contains the
1892 package-specific recipes for compiling the package and
1893 building binary package(s) from the source.
1897 It must start with the line <tt>#!/usr/bin/make -f</tt>,
1898 so that it can be invoked by saying its name rather than
1899 invoking <prgn>make</prgn> explicitly.
1903 Since an interactive <tt>debian/rules</tt> script makes it
1904 impossible to auto-compile that package and also makes it
1905 hard for other people to reproduce the same binary
1906 package, all <em>required targets</em> MUST be
1907 non-interactive. At a minimum, required targets are the
1908 ones called by <prgn>dpkg-buildpackage</prgn>, namely,
1909 <em>clean</em>, <em>binary</em>, <em>binary-arch</em>,
1910 <em>binary-indep</em>, and <em>build</em>. It also follows
1911 that any target that these targets depend on must also be
1916 The required and optional targets are as follows:
1918 <tag><tt>build</tt></tag>
1921 This should perform all non-interactive configuration
1922 and compilation of the package. If a package has an
1923 interactive pre-build configuration routine, the
1924 Debianized source package must either be built after
1925 this has taken place (so that the binary package can
1926 be built without rerunning the configuration) or the
1927 configuration routine modified to become
1928 non-interactive. (The latter is preferable if there
1929 are architecture-specific features detected by the
1930 configuration routine.)
1934 For some packages, notably ones where the same
1935 source tree is compiled in different ways to produce
1936 two binary packages, the <prgn>build</prgn> target
1937 does not make much sense. For these packages it is
1938 good enough to provide two (or more) targets
1939 (<tt>build-a</tt> and <tt>build-b</tt> or whatever)
1940 for each of the ways of building the package, and a
1941 <prgn>build</prgn> target that does nothing. The
1942 <prgn>binary</prgn> target will have to build the
1943 package in each of the possible ways and make the
1944 binary package out of each.
1948 The <prgn>build</prgn> target must not do anything
1949 that might require root privilege.
1953 The <prgn>build</prgn> target may need to run the
1954 <prgn>clean</prgn> target first - see below.
1958 When a package has a configuration and build routine
1959 which takes a long time, or when the makefiles are
1960 poorly designed, or when <prgn>build</prgn> needs to
1961 run <prgn>clean</prgn> first, it is a good idea to
1962 <tt>touch build</tt> when the build process is
1963 complete. This will ensure that if <tt>debian/rules
1964 build</tt> is run again it will not rebuild the whole
1968 Another common way to do this is for <prgn>build</prgn>
1969 to depend on <prgn>build-stamp</prgn> and to do
1970 nothing else, and for the <prgn>build-stamp</prgn>
1971 target to do the building and to <tt>touch
1972 build-stamp</tt> on completion. This is
1973 especially useful if the build routine creates a
1974 file or directory called <tt>build</tt>; in such a
1975 case, <prgn>build</prgn> will need to be listed as
1976 a phony target (i.e., as a dependency of the
1977 <tt>.PHONY</tt> target). See the documentation of
1978 <prgn>make</prgn> for more information on phony
1985 <tag><tt>binary</tt>, <tt>binary-arch</tt>,
1986 <tt>binary-indep</tt>
1990 The <prgn>binary</prgn> target must be all that is
1991 necessary for the user to build the binary package(s)
1992 produced from this source package. All of these
1993 targets are required to be non-interactive. It is
1994 split into two parts: <prgn>binary-arch</prgn> builds
1995 the binary packages which are specific to a particular
1996 architecture, and <prgn>binary-indep</prgn> builds
1997 those which are not.
2001 <prgn>binary</prgn> may be (and commonly is) a target
2002 with no commands which simply depends on
2003 <prgn>binary-arch</prgn> and
2004 <prgn>binary-indep</prgn>.
2008 Each <prgn>binary-*</prgn> target should depend on
2009 the <prgn>build</prgn> target, above, so that the
2010 package is built if it has not been already. It
2011 should then create the relevant binary package(s),
2012 using <prgn>dpkg-gencontrol</prgn> to make their
2013 control files and <prgn>dpkg-deb</prgn> to build
2014 them and place them in the parent of the top level
2019 Both the <prgn>binary-arch</prgn> and
2020 <prgn>binary-indep</prgn> targets <em>must</em> exist.
2021 If one of them has nothing to do (which will always be
2022 the case if the source generates only a single binary
2023 package, whether architecture-dependent or not), it
2024 must still exist and must always succeed.
2028 The <prgn>binary</prgn> targets must be invoked as
2032 The <prgn>fakeroot</prgn> package often allows one
2033 to build a package correctly even without being
2040 <tag><tt>clean</tt></tag>
2044 This must undo any effects that the <prgn>build</prgn>
2045 and <prgn>binary</prgn> targets may have had, except
2046 that it should leave alone any output files created in
2047 the parent directory by a run of a <prgn>binary</prgn>
2048 target. This target must be non-interactive.
2052 If a <prgn>build</prgn> file is touched at the end of
2053 the <prgn>build</prgn> target, as suggested above, it
2054 should be removed as the first action that
2055 <prgn>clean</prgn> performs, so that running
2056 <prgn>build</prgn> again after an interrupted
2057 <prgn>clean</prgn> doesn't think that everything is
2062 The <prgn>clean</prgn> target may need to be
2063 invoked as root if <prgn>binary</prgn> has been
2064 invoked since the last <prgn>clean</prgn>, or if
2065 <prgn>build</prgn> has been invoked as root (since
2066 <prgn>build</prgn> may create directories, for
2071 <tag><tt>get-orig-source</tt> (optional)</tag>
2075 This target fetches the most recent version of the
2076 original source package from a canonical archive site
2077 (via FTP or WWW, for example), does any necessary
2078 rearrangement to turn it into the original source
2079 tar file format described below, and leaves it in the
2084 This target may be invoked in any directory, and
2085 should take care to clean up any temporary files it
2090 This target is optional, but providing it if
2091 possible is a good idea.
2097 The <prgn>build</prgn>, <prgn>binary</prgn> and
2098 <prgn>clean</prgn> targets must be invoked with the current
2099 directory being the package's top-level directory.
2104 Additional targets may exist in <tt>debian/rules</tt>,
2105 either as published or undocumented interfaces or for the
2106 package's internal use.
2110 The architectures we build on and build for are determined
2111 by <prgn>make</prgn> variables using the utility
2112 <prgn>dpkg-architecture</prgn>. You can determine the
2113 Debian architecture and the GNU style architecture
2114 specification string for the build machine (the machine type
2115 we are building on) as well as for the host machine (the
2116 machine type we are building for). Here is a list of
2117 supported <prgn>make</prgn> variables:
2118 <list compact="compact">
2120 <p><tt>DEB_*_ARCH</tt> (the Debian architecture)</p>
2123 <p><tt>DEB_*_GNU_TYPE</tt> (the GNU style architecture
2124 specification string)</p>
2127 <p><tt>DEB_*_GNU_CPU</tt> (the CPU part of
2128 <tt>DEB_*_GNU_TYPE</tt>)</p>
2131 <p><tt>DEB_*_GNU_SYSTEM</tt> (the System part of
2132 <tt>DEB_*_GNU_TYPE</tt>)</p>
2134 where <tt>*</tt> is either <tt>BUILD</tt> for specification of
2135 the build machine or <tt>HOST</tt> for specification of the
2140 Backward compatibility can be provided in the rules file
2141 by setting the needed variables to suitable default
2142 values; please refer to the documentation of
2143 <prgn>dpkg-architecture</prgn> for details.
2147 It is important to understand that the <tt>DEB_*_ARCH</tt>
2148 string only determines which Debian architecture we are
2149 building on or for. It should not be used to get the CPU
2150 or system information; the GNU style variables should be
2155 <sect id="dpkgchangelog"><heading><tt>debian/changelog</tt>
2159 This file records the changes to the Debian-specific parts of the
2163 Though there is nothing stopping an author who is also
2164 the Debian maintainer from using it for all their
2165 changes, it will have to be renamed if the Debian and
2166 upstream maintainers become different people. In such a
2167 case, however, it might be better to maintain the
2168 package as a non-native package.
2174 It has a special format which allows the package building
2175 tools to discover which version of the package is being
2176 built and find out other release-specific information.
2180 That format is a series of entries like this:
2182 <var>package</var> (<var>version</var>) <var>distribution(s)</var>; urgency=<var>urgency</var>
2184 * <var>change details</var>
2185 <var>more change details</var>
2186 * <var>even more change details</var>
2188 -- <var>maintainer name and email address</var> <var>date</var>
2193 <var>package</var> and <var>version</var> are the source
2194 package name and version number.
2198 <var>distribution(s)</var> lists the distributions where
2199 this version should be installed when it is uploaded - it
2200 is copied to the <tt>Distribution</tt> field in the
2201 <tt>.changes</tt> file. See <ref id="f-Distribution">.
2205 <var>urgency</var> is the value for the <tt>Urgency</tt>
2206 field in the <tt>.changes</tt> file for the upload. It is
2207 not possible to specify an urgency containing commas; commas
2208 are used to separate
2209 <tt><var>keyword</var>=<var>value</var></tt> settings in the
2210 <prgn>dpkg</prgn> changelog format (though there is
2211 currently only one useful <var>keyword</var>,
2215 Usual urgency values are <tt>low</tt>, <tt>medium</tt>,
2216 <tt>high</tt> and <tt>critical</tt>. They have an
2217 effect on how quickly a package will be considered for
2218 inclusion into the <tt>testing</tt> distribution, and
2219 give an indication of the importance of any fixes
2220 included in this upload.
2226 The change details may in fact be any series of lines
2227 starting with at least two spaces, but conventionally each
2228 change starts with an asterisk and a separating space and
2229 continuation lines are indented so as to bring them in
2230 line with the start of the text above. Blank lines may be
2231 used here to separate groups of changes, if desired.
2235 If this upload resolves bugs recorded in the Bug Tracking
2236 System (BTS), they may be automatically closed on the
2237 inclusion of this package into the Debian archive by
2238 including the string: <tt>closes: Bug#<var>nnnnn</var></tt>
2239 in the change details.
2242 To be precise, the string should match the following
2243 Perl regular expression (where $pound=<tt>#</tt>;):
2245 /closes:\s*(?:bug)?${pound}?\s?\d+(?:,\s*(?:bug)?\${pound}?\s?\d+)*/i
2248 <p>We had to introduce the $pound variable in the
2249 regexp above because otherwise the utilities
2250 rendering the policy documents gor confused by a
2251 backslashed "#" symbol.
2254 Then all of the bug numbers listed will be closed by the
2255 archive maintenance script (<prgn>katie</prgn>), or in
2256 the case of an NMU, marked as fixed.
2262 The maintainer name and email address used in the changelog
2263 should be the details of the person uploading <em>this</em>
2264 version. They are <em>not</em> necessarily those of the
2265 usual package maintainer. The information here will be
2266 copied to the <tt>Changed-By</tt> field in the
2267 <tt>.changes</tt> file, and then later used to send an
2268 acknowledgement when the upload has been installed.
2272 The <var>date</var> should be in RFC822 format
2275 This is generated by the <prgn>822-date</prgn>
2278 </footnote>; it should include the time zone specified
2279 numerically, with the time zone name or abbreviation
2280 optionally present as a comment in parentheses.
2284 The first `title' line with the package name should start
2285 at the left hand margin; the `trailer' line with the
2286 maintainer and date details should be preceded by exactly
2287 one space. The maintainer details and the date must be
2288 separated by exactly two spaces.
2291 <sect1><heading>Defining alternative changelog formats</heading>
2294 It is possible to use a different format to the standard
2295 one, by providing a parser for the format you wish to
2299 A changelog parser must not interact with the user at
2305 <sect id="srcsubstvars"><heading><tt>debian/substvars</tt>
2306 and variable substitutions </heading>
2309 When <prgn>dpkg-gencontrol</prgn>,
2310 <prgn>dpkg-genchanges</prgn> and <prgn>dpkg-source</prgn>
2311 generate control files they perform variable substitutions
2312 on their output just before writing it. Variable
2313 substitutions have the form
2314 <tt>${<var>variable-name</var>}</tt>. The optional file
2315 <tt>debian/substvars</tt> contains variable substitutions to
2316 be used; variables can also be set directly from
2317 <tt>debian/rules</tt> using the <tt>-V</tt> option to the
2318 source packaging commands, and certain predefined variables
2323 The <tt>debian/substvars</tt> file is usually generated and
2324 modified dynamically by <tt>debian/rules</tt> targets; in
2325 this case it must be removed by the <prgn>clean</prgn>
2330 See <manref name="dpkg-source" section="1"> for full
2331 details about source variable substitutions, including the
2332 format of <tt>debian/substvars</tt>.</p>
2335 <sect id="debianfiles"><heading><tt>debian/files</tt>
2339 This file is not a permanent part of the source tree; it
2340 is used while building packages to record which files are
2341 being generated. <prgn>dpkg-genchanges</prgn> uses it
2342 when it generates a <tt>.changes</tt> file.
2346 It should not exist in a shipped source package, and so it
2347 (and any backup files or temporary files such as
2351 <tt>files.new</tt> is used as a temporary file by
2352 <prgn>dpkg-gencontrol</prgn> and
2353 <prgn>dpkg-distaddfile</prgn> - they write a new
2354 version of <tt>files</tt> here before renaming it,
2355 to avoid leaving a corrupted copy if an error
2358 </footnote>) should be removed by the
2359 <prgn>clean</prgn> target. It may also be wise to
2360 ensure a fresh start by emptying or removing it at the
2361 start of the <prgn>binary</prgn> target.
2365 When <prgn>dpkg-gencontrol</prgn> is run for a binary
2366 package, it adds an entry to <tt>debian/files</tt> for the
2367 <tt>.deb</tt> file that will be created when <prgn>dpkg-deb
2368 --build</prgn> is run for that binary package. So for most
2369 packages all that needs to be done with this file is to
2370 delete it in the <prgn>clean</prgn> target.
2374 If a package upload includes files besides the source
2375 package and any binary packages whose control files were
2376 made with <prgn>dpkg-gencontrol</prgn> then they should be
2377 placed in the parent of the package's top-level directory
2378 and <prgn>dpkg-distaddfile</prgn> should be called to add
2379 the file to the list in <tt>debian/files</tt>.</p>
2382 <sect id="restrictions"><heading>Restrictions on objects in source packages
2386 The source package may not contain any hard links
2389 This is not currently detected when building source
2390 packages, but only when extracting
2394 Hard links may be permitted at some point in the
2395 future, but would require a fair amount of
2398 </footnote>, device special files, sockets or setuid or
2402 Setgid directories are allowed.
2407 <sect id="descriptions"><heading>Descriptions of packages - the
2408 <tt>Description</tt> field </heading>
2411 The description is intended to describe the program to a user
2412 who has never met it before so that they know whether they
2413 want to install it. It should also give information about the
2414 significant dependencies and conflicts between this package
2415 and others, so that the user knows why these dependencies and
2416 conflicts have been declared.
2419 <sect1><heading>Notes about writing descriptions
2423 The single line synopsis should be kept brief - certainly
2424 under 80 characters.
2428 Do not include the package name in the synopsis line. The
2429 display software knows how to display this already, and you
2430 do not need to state it. Remember that in many situations
2431 the user may only see the synopsis line - make it as
2432 informative as you can.
2436 Do not try to continue the single line synopsis into the
2437 extended description. This will not work correctly when
2438 the full description is displayed, and makes no sense
2439 where only the summary (the single line synopsis) is
2444 The extended description should describe what the package
2445 does and how it relates to the rest of the system (in terms
2446 of, for example, which subsystem it is which part of).
2450 The description field needs to make sense to anyone, even
2451 people who have no idea about any of the things the
2455 The blurb that comes with a program in its
2456 announcements and/or <prgn>README</prgn> files is
2457 rarely suitable for use in a description. It is
2458 usually aimed at people who are already in the
2459 community where the package is used.
2465 Put important information first, both in the synopsis and
2466 extended description. Sometimes only the first part of the
2467 synopsis or of the description will be displayed. You can
2468 assume that there will usually be a way to see the whole
2469 extended description.
2473 You may include information about dependencies and so forth
2474 in the extended description, if you wish.
2478 Do not use tab characters. Their effect is not predictable.
2486 <chapt id="maintainerscripts"><heading>Package maintainer scripts
2487 and installation procedure
2490 <sect><heading>Introduction to package maintainer scripts
2494 It is possible to supply scripts as part of a package which
2495 the package management system will run for you when your
2496 package is installed, upgraded or removed.
2500 These scripts are the files <tt>preinst</tt>,
2501 <tt>postinst</tt>, <tt>prerm</tt> and <tt>postrm</tt> in the
2502 control area of the package. They must be proper executable
2503 files; if they are scripts (which is recommended), they must
2504 start with the usual <tt>#!</tt> convention. They should be
2505 readable and executable by anyone, and not world-writable.
2509 The package management system looks at the exit status from
2510 these scripts. It is important that they exit with a
2511 non-zero status if there is an error, so that the package
2512 management system can stop its processing. For shell
2513 scripts this means that you <em>almost always</em> need to
2514 use <tt>set -e</tt> (this is usually true when writing shell
2515 scripts, in fact). It is also important, of course, that
2516 they don't exit with a non-zero status if everything went
2521 When a package is upgraded a combination of the scripts from
2522 the old and new packages is called during the upgrade
2523 procedure. If your scripts are going to be at all
2524 complicated you need to be aware of this, and may need to
2525 check the arguments to your scripts.
2529 Broadly speaking the <prgn>preinst</prgn> is called before
2530 (a particular version of) a package is installed, and the
2531 <prgn>postinst</prgn> afterwards; the <prgn>prerm</prgn>
2532 before (a version of) a package is removed and the
2533 <prgn>postrm</prgn> afterwards.
2537 Programs called from maintainer scripts should not normally
2538 have a path prepended to them. Before installation is
2539 started, the package management system checks to see if the
2540 programs <prgn>ldconfig</prgn>,
2541 <prgn>start-stop-daemon</prgn>, <prgn>install-info</prgn>,
2542 and <prgn>update-rc.d</prgn> can be found via the
2543 <tt>PATH</tt> environment variable. Those programs, and any
2544 other program that one would expect to be on the
2545 <tt>PATH</tt>, should thus be invoked without an absolute
2546 pathname. Maintainer scripts should also not reset the
2547 <tt>PATH</tt>, though they might choose to modify it by
2548 prepending or appending package-specific directories. These
2549 considerations really apply to all shell scripts.</p>
2553 <heading>Maintainer scripts Idempotency</heading>
2556 It is necessary for the error recovery procedures that the
2557 scripts be idempotent. This means that if it is run
2558 successfully, and then it is called again, it doesn't bomb
2559 out or cause any harm, but just ensures that everything is
2560 the way it ought to be. If the first call failed, or
2561 aborted half way through for some reason, the second call
2562 should merely do the things that were left undone the first
2563 time, if any, and exit with a success status if everything
2567 This is so that if an error occurs, the user interrupts
2568 <prgn>dpkg</prgn> or some other unforeseen circumstance
2569 happens you don't leave the user with a badly-broken
2570 package when <prgn>dpkg</prgn> attempts to repeat the
2578 <heading>Controlling terminal for maintainer scripts</heading>
2581 The maintainer scripts are guaranteed to run with a
2582 controlling terminal and can interact with the user.
2583 If they need to prompt for passwords, do full-screen
2584 interaction or something similar you should do these
2585 things to and from <tt>/dev/tty</tt>, since
2586 <prgn>dpkg</prgn> will at some point redirect scripts'
2587 standard input and output so that it can log the
2588 installation process. Likewise, because these scripts
2589 may be executed with standard output redirected into a
2590 pipe for logging purposes, Perl scripts should set
2591 unbuffered output by setting <tt>$|=1</tt> so that the
2592 output is printed immediately rather than being
2597 Each script should return a zero exit status for
2598 success, or a nonzero one for failure.
2602 <sect id="mscriptsinstact"><heading>Summary of ways maintainer
2607 <list compact="compact">
2609 <p><var>new-preinst</var> <tt>install</tt></p>
2612 <p><var>new-preinst</var> <tt>install</tt>
2613 <var>old-version</var></p>
2616 <p><var>new-preinst</var> <tt>upgrade</tt>
2617 <var>old-version</var></p>
2620 <p><var>old-preinst</var> <tt>abort-upgrade</tt>
2621 <var>new-version</var>
2627 <list compact="compact">
2629 <p><var>postinst</var> <tt>configure</tt>
2630 <var>most-recently-configured-version</var></p>
2633 <p><var>old-postinst</var> <tt>abort-upgrade</tt>
2634 <var>new-version</var></p>
2637 <p><var>conflictor's-postinst</var> <tt>abort-remove</tt>
2638 <tt>in-favour</tt> <var>package</var>
2639 <var>new-version</var></p>
2643 <var>deconfigured's-postinst</var>
2644 <tt>abort-deconfigure</tt> <tt>in-favour</tt>
2645 <var>failed-install-package</var> <var>version</var>
2646 <tt>removing</tt> <var>conflicting-package</var>
2653 <list compact="compact">
2655 <p><var>prerm</var> <tt>remove</tt></p>
2658 <p><var>old-prerm</var> <tt>upgrade</tt>
2659 <var>new-version</var></p>
2662 <p><var>new-prerm</var> <tt>failed-upgrade</tt>
2663 <var>old-version</var></p>
2666 <p><var>conflictor's-prerm</var> <tt>remove</tt>
2667 <tt>in-favour</tt> <var>package</var>
2668 <var>new-version</var></p>
2672 <var>deconfigured's-prerm</var> <tt>deconfigure</tt>
2673 <tt>in-favour</tt> <var>package-being-installed</var>
2674 <var>version</var> <tt>removing</tt>
2675 <var>conflicting-package</var>
2682 <list compact="compact">
2684 <p><var>postrm</var> <tt>remove</tt></p>
2687 <p><var>postrm</var> <tt>purge</tt></p>
2691 <var>old-postrm</var> <tt>upgrade</tt>
2692 <var>new-version</var></p>
2695 <p><var>new-postrm</var> <tt>failed-upgrade</tt>
2696 <var>old-version</var></p>
2699 <p><var>new-postrm</var> <tt>abort-install</tt></p>
2702 <p><var>new-postrm</var> <tt>abort-install</tt>
2703 <var>old-version</var></p>
2706 <p><var>new-postrm</var> <tt>abort-upgrade</tt>
2707 <var>old-version</var></p>
2711 <var>disappearer's-postrm</var> <tt>disappear</tt>
2712 <var>overwriter</var>
2713 <var>overwriter-version</var></p></item>
2718 <sect id="unpackphase"><heading>Details of unpack phase of
2719 installation or upgrade
2723 The procedure on installation/upgrade/overwrite/disappear
2724 (i.e., when running <tt>dpkg --unpack</tt>, or the unpack
2725 stage of <tt>dpkg --install</tt>) is as follows. In each
2726 case, if a major error occurs (unless listed below) the
2727 actions are, in general, run backwards - this means that the
2728 maintainer scripts are run with different arguments in
2729 reverse order. These are the `error unwind' calls listed
2737 <p>If a version of the package is already
2740 <var>old-prerm</var> upgrade <var>new-version</var>
2745 If the script runs but exits with a non-zero
2746 exit status, <prgn>dpkg</prgn> will attempt:
2748 <var>new-prerm</var> failed-upgrade <var>old-version</var>
2750 Error unwind, for both the above cases:
2752 <var>old-postinst</var> abort-upgrade <var>new-version</var>
2760 <p>If a `conflicting' package is being removed at the same time:
2764 If any packages depended on that conflicting
2765 package and <tt>--auto-deconfigure</tt> is
2766 specified, call, for each such package:
2768 <var>deconfigured's-prerm</var> deconfigure \
2769 in-favour <var>package-being-installed</var> <var>version</var> \
2770 removing <var>conflicting-package</var> <var>version</var>
2774 <var>deconfigured's-postinst</var> abort-deconfigure \
2775 in-favour <var>package-being-installed-but-failed</var> <var>version</var> \
2776 removing <var>conflicting-package</var> <var>version</var>
2778 The deconfigured packages are marked as
2779 requiring configuration, so that if
2780 <tt>--install</tt> is used they will be
2781 configured again if possible.</p>
2784 <p>To prepare for removal of the conflicting package, call:
2786 <var>conflictor's-prerm</var> remove in-favour <var>package</var> <var>new-version</var>
2790 <var>conflictor's-postinst</var> abort-remove \
2791 in-favour <var>package</var> <var>new-version</var>
2802 <p>If the package is being upgraded, call:
2804 <var>new-preinst</var> upgrade <var>old-version</var>
2809 Otherwise, if the package had some configuration
2810 files from a previous version installed (i.e., it
2811 is in the `configuration files only' state):
2813 <var>new-preinst</var> install <var>old-version</var>
2817 <p>Otherwise (i.e., the package was completely purged):
2819 <var>new-preinst</var> install
2821 Error unwind actions, respectively:
2823 <var>new-postrm</var> abort-upgrade <var>old-version</var>
2824 <var>new-postrm</var> abort-install <var>old-version</var>
2825 <var>new-postrm</var> abort-install
2835 The new package's files are unpacked, overwriting any
2836 that may be on the system already, for example any
2837 from the old version of the same package or from
2838 another package. Backups of the old files are kept
2839 temporarily, and if anything goes wrong the package
2840 management system will attempt to put them back as
2841 part of the error unwind.
2845 It is an error for a package to contains files which
2846 are on the system in another package, unless
2847 <tt>Replaces</tt> is used (see <ref id="replaces">).
2849 The following paragraph is not currently the case:
2850 Currently the <tt>- - force-overwrite</tt> flag is
2851 enabled, downgrading it to a warning, but this may not
2857 It is a more serious error for a package to contain a
2858 plain file or other kind of non-directory where another
2859 package has a directory (again, unless
2860 <tt>Replaces</tt> is used). This error can be
2861 overridden if desired using
2862 <tt>--force-overwrite-dir</tt>, but this is not
2867 Packages which overwrite each other's files produce
2868 behavior which, though deterministic, is hard for the
2869 system administrator to understand. It can easily
2870 lead to `missing' programs if, for example, a package
2871 is installed which overwrites a file from another
2872 package, and is then removed again.
2875 Part of the problem is due to what is arguably a
2876 bug in <prgn>dpkg</prgn>.
2882 A directory will never be replaced by a symbolic link
2883 to a directory or vice versa; instead, the existing
2884 state (symlink or not) will be left alone and
2885 <prgn>dpkg</prgn> will follow the symlink if there is
2893 <p>If the package is being upgraded, call
2895 <var>old-postrm</var> upgrade <var>new-version</var>
2899 <p>If this fails, <prgn>dpkg</prgn> will attempt:
2901 <var>new-postrm</var> failed-upgrade <var>old-version</var>
2903 Error unwind, for both cases:
2905 <var>old-preinst</var> abort-upgrade <var>new-version</var>
2911 This is the point of no return - if
2912 <prgn>dpkg</prgn> gets this far, it won't back off
2913 past this point if an error occurs. This will
2914 leave the package in a fairly bad state, which
2915 will require a successful re-installation to clear
2916 up, but it's when <prgn>dpkg</prgn> starts doing
2917 things that are irreversible.
2922 Any files which were in the old version of the package
2923 but not in the new are removed.</p>
2926 <p>The new file list replaces the old.</p>
2929 <p>The new maintainer scripts replace the old.</p>
2933 <p>Any packages all of whose files have been overwritten during the
2934 installation, and which aren't required for
2935 dependencies, are considered to have been removed.
2936 For each such package
2939 <p><prgn>dpkg</prgn> calls:
2941 <var>disappearer's-postrm</var> disappear \
2942 <var>overwriter</var> <var>overwriter-version</var>
2947 <p>The package's maintainer scripts are removed.
2952 It is noted in the status database as being in a
2953 sane state, namely not installed (any conffiles
2954 it may have are ignored, rather than being
2955 removed by <prgn>dpkg</prgn>). Note that
2956 disappearing packages do not have their prerm
2957 called, because <prgn>dpkg</prgn> doesn't know
2958 in advance that the package is going to
2967 Any files in the package we're unpacking that are also
2968 listed in the file lists of other packages are removed
2969 from those lists. (This will lobotomize the file list
2970 of the `conflicting' package if there is one.)
2975 The backup files made during installation, above, are
2982 The new package's status is now sane, and recorded as
2987 Here is another point of no return - if the
2988 conflicting package's removal fails we do not unwind
2989 the rest of the installation; the conflicting package
2990 is left in a half-removed limbo.
2996 If there was a conflicting package we go and do the
2997 removal actions (described below), starting with the
2998 removal of the conflicting package's files (any that
2999 are also in the package being installed have already
3000 been removed from the conflicting package's file list,
3001 and so do not get removed now).
3008 <sect><heading>Details of configuration</heading>
3011 When we configure a package (this happens with <tt>dpkg
3012 --install</tt>, or with <tt>--configure</tt>), we first
3013 update any <tt>conffile</tt>s and then call:
3015 <var>postinst</var> configure <var>most-recently-configured-version</var>
3020 No attempt is made to unwind after errors during
3025 If there is no most recently configured version
3026 <prgn>dpkg</prgn> will pass a null argument; older versions
3027 of dpkg may pass <tt><unknown></tt> (including the
3028 angle brackets) in this case. Even older ones do not pass a
3029 second argument at all, under any circumstances.
3033 <sect><heading>Details of removal and/or configuration purging
3041 <var>prerm</var> remove
3047 The package's files are removed (except <tt>conffile</tt>s).
3052 <var>postrm</var> remove
3057 All the maintainer scripts except the <tt>postrm</tt>
3062 If we aren't purging the package we stop here. Note
3063 that packages which have no <tt>postrm</tt> and no
3064 <tt>conffile</tt>s are automatically purged when
3065 removed, as there is no difference except for the
3066 <prgn>dpkg</prgn> status.</p>
3070 The conffiles and any backup files (<tt>~</tt>-files,
3071 <tt>#*#</tt> files, <tt>%</tt>-files,
3072 <tt>.dpkg-{old,new,tmp}</tt>, etc.) are removed.</p>
3076 <var>postrm</var> purge
3080 <p>The package's file list is removed.</p>
3083 No attempt is made to unwind after errors during
3090 <chapt id="relationships"><heading>Declaring relationships between
3094 Packages can declare in their control file that they have
3095 certain relationships to other packages - for example, that
3096 they may not be installed at the same time as certain other
3097 packages, and/or that they depend on the presence of others,
3098 or that they should overwrite files in certain other packages
3103 This is done using the <tt>Depends</tt>, <tt>Recommends</tt>,
3104 <tt>Suggests</tt>, <tt>Enhances</tt>, <tt>Conflicts</tt>,
3105 <tt>Provides</tt> and <tt>Replaces</tt> control file fields.
3109 Source packages may declare relationships to binary packages,
3110 saying that they require certain binary packages to be
3111 installed or absent at the time of building the package.
3115 This is done using the <tt>Build-Depends</tt>,
3116 <tt>Build-Depends-Indep</tt>, <tt>Build-Conflicts</tt>, and
3117 <tt>Build-Conflicts-Indep</tt> control file fields.
3120 <sect id="depsyntax"><heading>Syntax of relationship fields
3124 These fields all have a uniform syntax. They are a list of
3125 package names separated by commas.
3129 In the <tt>Depends</tt>, <tt>Recommends</tt>,
3130 <tt>Suggests</tt>, <tt>Pre-Depends</tt>,
3131 <tt>Build-Depends</tt> and <tt>Build-Depends-Indep</tt>
3132 control file fields of the package, which declare
3133 dependencies on other packages, the package names listed may
3134 also include lists of alternative package names, separated
3135 by vertical bar symbols <tt>|</tt> (pipe symbols). In such
3136 a case, the presence of any one of the alternative packages
3137 is installed, that part of the dependency is considered to
3142 All the fields except <tt>Provides</tt> may restrict their
3143 applicability to particular versions of each named package.
3144 This is done in parentheses after each individual package
3145 name; the parentheses should contain a relation from the
3146 list below followed by a version number, in the format
3147 described in <ref id="versions">.
3151 The relations allowed are <tt><<</tt>, <tt><=</tt>,
3152 <tt>=</tt>, <tt>>=</tt> and <tt>>></tt> for
3153 strictly earlier, earlier or equal, exactly equal, later or
3154 equal and strictly later, respectively. The forms
3155 <tt><</tt> and <tt>></tt> were used to mean
3156 earlier/later or equal, rather than strictly earlier/later,
3157 so they should not appear in new packages (though
3158 <prgn>dpkg</prgn> still supports them).
3162 Whitespace may appear at any point in the version
3163 specification, and must appear where it's necessary to
3164 disambiguate; it is not otherwise significant. For
3165 consistency and in case of future changes to
3166 <prgn>dpkg</prgn> it is recommended that a single space be
3167 used after a version relationship and before a version
3168 number; it is usual also to put a single space after each
3169 comma, on either side of each vertical bar, and before each
3178 Depends: libc5 (>= 5.2.18-4), mime-support, csh | tcsh
3183 All fields that specify build-time relationships
3184 (<tt>Build-Depends</tt>, <tt>Build-Depends-Indep</tt>,
3185 <tt>Build-Conflicts</tt> and <tt>Build-Conflicts-Indep</tt>)
3186 may be restricted to a certain set of architectures. This
3187 is done in brackets after each individual package name and
3188 the optional version specification. The brackets enclose a
3189 list of Debian architecture names separated by whitespace.
3190 Exclamation marks may be prepended to each of the names.
3191 (It is not permitted for some names to be prepended with
3192 exclamation marks and others not.) If the current Debian
3193 host architecture is not in this list and there are no
3194 exclamation marks in the list, or it is in the list with a
3195 prepended exclamation mark, the package name and the
3196 associated version specification are ignored completely for
3197 the purposes of defining the relationships.
3204 Build-Depends-Indep: texinfo
3205 Build-Depends: kernel-headers-2.2.10 [!hurd-i386],
3206 hurd-dev [hurd-i386], gnumach-dev [hurd-i386]
3212 <heading>Binary Dependencies - <tt>Depends</tt>,
3213 <tt>Recommends</tt>, <tt>Suggests</tt>, <tt>Enhances</tt>,
3214 <tt>Pre-Depends</tt>
3218 These five fields are used to declare a dependency
3219 relationship by one package on another. They appear in the
3220 depending package's control file.
3224 All but <tt>Pre-Depends</tt> and <tt>Conflicts</tt>
3225 (discussed below) take effect <em>only</em> when a package
3226 is to be configured. They do not prevent a package being on
3227 the system in an unconfigured state while its dependencies
3228 are unsatisfied, and it is possible to replace a package
3229 whose dependencies are satisfied and which is properly
3230 installed with a different version whose dependencies are
3231 not and cannot be satisfied; when this is done the depending
3232 package will be left unconfigured (since attempts to
3233 configure it will give errors) and will not function
3238 For this reason packages in an installation run are usually
3239 all unpacked first and all configured later; this gives
3240 later versions of packages with dependencies on later
3241 versions of other packages the opportunity to have their
3242 dependencies satisfied.
3246 Thus <tt>Depends</tt> allows package maintainers to impose
3247 an order in which packages should be configured.
3249 <tag><tt>Depends</tt></tag>
3252 <p>This declares an absolute dependency.
3256 The <tt>Depends</tt> field should be used if the
3257 depended-on package is required for the depending
3258 package to provide a significant amount of
3262 <tag><tt>Recommends</tt></tag>
3264 <p>This declares a strong, but not absolute, dependency.
3268 The <tt>Recommends</tt> field should list packages
3269 that would be found together with this one in all but
3270 unusual installations.</p>
3273 <tag><tt>Suggests</tt></tag>
3277 This is used to declare that one package may be more
3278 useful with one or more others. Using this field
3279 tells the packaging system and the user that the
3280 listed packages are related to this one and can
3281 perhaps enhance its usefulness, but that installing
3282 this one without them is perfectly reasonable.
3286 <tag><tt>Enhances</tt></tag>
3289 This field is similar to Suggests but works in the
3290 opposite direction. It is used to declare that a
3291 package can enhance the functionality of another
3296 <tag><tt>Pre-Depends</tt></tag>
3300 This field is like <tt>Depends</tt>, except that it
3301 also forces <prgn>dpkg</prgn> to complete installation
3302 of the packages named before even starting the
3303 installation of the package which declares the
3308 <tt>Pre-Depends</tt> should be used sparingly,
3309 preferably only by packages whose premature upgrade or
3310 installation would hamper the ability of the system to
3311 continue with any upgrade that might be in progress.
3315 When the package declaring it is being configured, a
3316 <tt>Pre-Dependency</tt> will be considered satisfied
3317 only if the depending package has been correctly
3318 configured, just as if an ordinary <tt>Depends</tt>
3323 However, when a package declaring a Pre-dependency is
3324 being unpacked the predependency can be satisfied even
3325 if the depended-on package(s) are only unpacked or
3326 half-configured, provided that they have been
3327 configured correctly at some point in the past (and
3328 not removed or partially removed since). In this case
3329 both the previously-configured and currently unpacked
3330 or half-configured versions must satisfy any version
3331 clause in the <tt>Pre-Depends</tt> field.
3337 When selecting which level of dependency to use you should
3338 consider how important the depended-on package is to the
3339 functionality of the one declaring the dependency. Some
3340 packages are composed of components of varying degrees of
3341 importance. Such a package should list using
3342 <tt>Depends</tt> the package(s) which are required by the
3343 more important components. The other components'
3344 requirements may be mentioned as Suggestions or
3345 Recommendations, as appropriate to the components' relative
3350 <sect id="conflicts"><heading>Alternative binary packages -
3351 <tt>Conflicts</tt> and <tt>Replaces</tt>
3355 When one binary package declares a conflict with another
3356 <prgn>dpkg</prgn> will refuse to allow them to be installed
3357 on the system at the same time.
3361 If one package is to be installed, the other must be removed
3362 first - if the package being installed is marked as
3363 replacing (<ref id="replaces">) the one on the system, or
3364 the one on the system is marked as deselected, or both
3365 packages are marked <tt>Essential</tt>, then
3366 <prgn>dpkg</prgn> will automatically remove the package
3367 which is causing the conflict, otherwise it will halt the
3368 installation of the new package with an error. This
3369 mechanism specifically doesn't work when the installed
3370 package is <tt>Essential</tt>, but the new package is not.
3375 A package will not cause a conflict merely because its
3376 configuration files are still installed; it must be at least
3381 A special exception is made for packages which declare a
3382 conflict with their own package name, or with a virtual
3383 package which they provide (see below): this does not
3384 prevent their installation, and allows a package to conflict
3385 with others providing a replacement for it. You use this
3386 feature when you want the package in question to be the only
3387 package providing something.
3391 A <tt>Conflicts</tt> entry should almost never have an
3392 `earlier than' version clause. This would prevent
3393 <prgn>dpkg</prgn> from upgrading or installing the package
3394 which declared such a conflict until the upgrade or removal
3395 of the conflicted-with package had been completed.
3399 <sect id="virtual"><heading>Virtual packages - <tt>Provides</tt>
3403 As well as the names of actual (`concrete') packages, the
3404 package relationship fields <tt>Depends</tt>,
3405 <tt>Build-Depends</tt>, <tt>Build-Depends-Indep</tt>,
3406 <tt>Recommends</tt>, <tt>Suggests</tt>, <tt>Conflicts</tt>,
3407 <tt>Build-Conflicts</tt> and <tt>Build-Conflicts-Indep</tt> may
3408 mention virtual packages.
3412 A virtual package is one which appears in the
3413 <tt>Provides</tt> control file field of another package.
3414 The effect is as if the package(s) which provide a
3415 particular virtual package name had been listed by name
3416 everywhere the virtual package name appears.
3420 If there are both a real and a virtual package of the same
3421 name then the dependency may be satisfied (or the conflict
3422 caused) by either the real package or any of the virtual
3423 packages which provide it. This is so that, for example,
3429 and someone else releases an xemacs package they can say
3433 </example> and all will work in the interim (until a purely
3434 virtual package name is decided on and the <tt>emacs</tt>
3435 and <tt>vm</tt> packages are changed to use it).
3439 If a dependency or a conflict has a version number attached
3440 then only real packages will be considered to see whether
3441 the relationship is satisfied (or the prohibition violated,
3442 for a conflict) - it is assumed that a real package which
3443 provides the virtual package is not of the `right' version.
3444 So, a <tt>Provides</tt> field may not contain version
3445 numbers, and the version number of the concrete package
3446 which provides a particular virtual package will not be
3447 looked at when considering a dependency on or conflict with
3448 the virtual package name.
3452 It is likely that the ability will be added in a future
3453 release of <prgn>dpkg</prgn> to specify a version number for
3454 each virtual package it provides. This feature is not yet
3455 present, however, and is expected to be used only
3460 If you want to specify which of a set of real packages should be the
3461 default to satisfy a particular dependency on a virtual package, you
3462 should list the real package as an alternative before the virtual.
3467 <sect id="replaces"><heading><tt>Replaces</tt> - overwriting
3468 files and replacing packages
3472 The <tt>Replaces</tt> control file field has two purposes,
3473 which come into play in different situations.
3477 Virtual packages (<ref id="virtual">) are not considered
3478 when looking at a <tt>Replaces</tt> field - the packages
3479 declared as being replaced must be mentioned by their real
3483 <sect1><heading>Overwriting files in other packages
3487 Firstly, as mentioned before, it is usually an error for a
3488 package to contain files which are on the system in
3489 another package, though currently the
3490 <tt>--force-overwrite</tt> flag is enabled by default,
3491 downgrading the error to a warning,
3495 If the overwriting package declares that it replaces the
3496 one containing the file being overwritten then
3497 <prgn>dpkg</prgn> will proceed, and replace the file from
3498 the old package with that from the new. The file will no
3499 longer be listed as `owned' by the old package.
3503 If a package is completely replaced in this way, so that
3504 <prgn>dpkg</prgn> does not know of any files it still
3505 contains, it is considered to have disappeared. It will
3506 be marked as not wanted on the system (selected for
3507 removal) and not installed. Any conffiles details noted
3508 in the package will be ignored, as they will have been
3509 taken over by the replacing package(s). The package's
3510 <prgn>postrm</prgn> script will be run to allow the
3511 package to do any final cleanup required. See <ref
3512 id="mscriptsinstact">.
3516 In the future <prgn>dpkg</prgn> will discard files which
3517 would overwrite those from an already installed package
3518 which declares that it replaces the package being
3519 installed. This is so that you can install an older
3520 version of a package without problems.
3524 This usage of <tt>Replaces</tt> only takes effect when
3525 both packages are at least partially on the system at
3526 once, so that it can only happen if they do not conflict
3527 or if the conflict has been overridden.</p>
3530 <sect1><heading>Replacing whole packages, forcing their
3535 Secondly, <tt>Replaces</tt> allows the packaging system to
3536 resolve which package should be removed when there is a
3537 conflict - see <ref id="conflicts">. This usage only
3538 takes effect when the two packages <em>do</em> conflict,
3539 so that the two effects do not interfere with each other.
3544 <sect><heading>Relationships between source and binary packages -
3545 <tt>Build-Depends</tt>, <tt>Build-Depends-Indep</tt>,
3546 <tt>Build-Conflicts</tt>, <tt>Build-Conflicts-Indep</tt>
3550 A source package may declare a dependency or a conflict on a
3551 binary package. This is done with the control file fields
3552 <tt>Build-Depends</tt>, <tt>Build-Depends-Indep</tt>,
3553 <tt>Build-Conflicts</tt>, and
3554 <tt>Build-Conflicts-Indep</tt>. Their semantics are that
3555 the dependencies and conflicts they define must be satisfied
3556 (as defined earlier for binary packages), when one of the
3557 targets in <tt>debian/rules</tt> that the particular field
3558 applies to is invoked.
3561 <tag><tt>Build-Depends</tt>, <tt>Build-Conflicts</tt></tag>
3564 The <tt>Build-Depends</tt> and
3565 <tt>Build-Conflicts</tt> fields apply to the targets
3566 <tt>build</tt>, <tt>binary</tt>, <tt>binary-arch</tt>
3567 and <tt>binary-indep</tt>.
3570 <tag><tt>Build-Depends-Indep</tt>, <tt>Build-Conflicts-Indep</tt></tag>
3573 The <tt>Build-Depends-Indep</tt> and
3574 <tt>Build-Conflicts-Indep</tt> fields apply to the
3575 targets <tt>binary</tt> and <tt>binary-indep</tt>.
3586 <chapt id="conffiles"><heading>Configuration file handling
3590 <prgn>dpkg</prgn> can do a certain amount of automatic
3591 handling of package configuration files.
3595 Whether this mechanism is appropriate depends on a number of
3596 factors, but basically there are two approaches to any
3597 particular configuration file.
3601 The easy method is to ship a best-effort configuration in the
3602 package, and use <prgn>dpkg</prgn>'s conffile mechanism to
3603 handle updates. If the user is unlikely to want to edit the
3604 file, but you need them to be able to without losing their
3605 changes, and a new package with a changed version of the file
3606 is only released infrequently, this is a good approach.
3610 The hard method is to build the configuration file from
3611 scratch in the <prgn>postinst</prgn> script, and to take the
3612 responsibility for fixing any mistakes made in earlier
3613 versions of the package automatically. This will be
3614 appropriate if the file is likely to need to be different on
3619 <chapt id="sharedlibs"><heading>Shared libraries
3623 Packages containing shared libraries must be constructed with
3624 a little care to make sure that the shared library is always
3625 available. This is especially important for packages whose
3626 shared libraries are vitally important, such as the libc.
3630 Firstly, your package should install the shared libraries
3631 under their normal names. For example, the
3632 <prgn>libgdbm1</prgn> package should install
3633 <tt>libgdbm.so.1.7.3</tt> as
3634 <tt>/usr/lib/libgdbm.so.1.7.3</tt>. The files should not be
3635 renamed or re-linked by any prerm or postrm scripts;
3636 <prgn>dpkg</prgn> will take care of renaming things safely
3637 without affecting running programs, and attempts to interfere
3638 with this are likely to lead to problems.
3642 Secondly, your package should include the symlink that
3643 <prgn>ldconfig</prgn> would create for the shared libraries.
3644 For example, the <prgn>libgdbm1</prgn> package should include
3645 a symlink from <tt>/usr/lib/libgdbm.so.1</tt> to
3646 <tt>libgdbm.so.1.7.3</tt>. This is needed so that
3647 <prgn>ld.so</prgn> can find the library in between the time
3648 <prgn>dpkg</prgn> installs it and <prgn>ldconfig</prgn> is run
3649 in the <prgn>postinst</prgn> script. Furthermore, older
3650 versions of the package management system required the library
3651 must be placed before the symlink pointing to it in the
3652 <tt>.deb</tt> file. This is so that by the time
3653 <prgn>dpkg</prgn> comes to install the symlink (overwriting
3654 the previous symlink pointing at an older version of the
3655 library) the new shared library is already in place.
3656 Unfortunately, this was not not always possible, since it
3657 highly depends on the behavior of the file system. Some
3658 file systems (such as reiserfs) will reorder the files so it
3659 doesn't matter in what order you create them. Starting with
3660 release <tt>1.7.0</tt> <prgn>dpkg</prgn> will reorder the
3661 files itself when building a package.
3665 Thirdly, the development package should contain a symlink for
3666 the shared library without a version number. For example, the
3667 <tt>libgdbm1-dev</tt> package should include a symlink from
3668 <tt>/usr/lib/libgdm.so</tt> to <tt>libgdm.so.1.7.3</tt>. This
3669 symlink is needed by <prgn>ld</prgn> when compiling packages
3670 as it will only look for <tt>libgdm.so</tt> and
3671 <tt>libgdm.a</tt> when compiling dynamically or statically,
3676 Any package installing shared libraries in a directory that's listed
3677 in <tt>/etc/ld.so.conf</tt> or in one of the default library
3678 directories of <prgn>ld.so</prgn> (currently, these are <tt>/usr/lib</tt>
3679 and <tt>/lib</tt>) must call <prgn>ldconfig</prgn> in its <prgn>postinst</prgn>
3680 script if and only if the first argument is `configure'. However, it
3681 is important not to call <prgn>ldconfig</prgn> in the postrm or preinst
3682 scripts in the case where the package is being upgraded (see <ref
3683 id="unpackphase">), as <prgn>ldconfig</prgn> will see the temporary names
3684 that <prgn>dpkg</prgn> uses for the files while it is
3685 installing them and will make the shared library links point
3686 to them, just before <prgn>dpkg</prgn> continues the
3687 installation and removes the links!
3690 <sect id="shlibs"><heading>The <tt>shlibs</tt> File Format
3694 This file is for use by <prgn>dpkg-shlibdeps</prgn> and is
3695 required when your package provides shared libraries.
3699 Each line is of the form:
3701 <var>library-name</var> <var>version-or-soname</var> <var>dependencies ...</var>
3706 <var>library-name</var> is the name of the shared library,
3707 for example <tt>libc5</tt>.
3711 <var>version-or-soname</var> is the soname of the library -
3712 i.e., the thing that must exactly match for the library to be
3713 recognized by <prgn>ld.so</prgn>. Usually this is the major
3714 version number of the library.
3718 <var>dependencies</var> has the same syntax as a dependency
3719 field in a binary package control file. It should give
3720 details of which package(s) are required to satisfy a binary
3721 built against the version of the library contained in the
3722 package. See <ref id="depsyntax">.
3726 For example, if the package <tt>foo</tt> contains
3727 <tt>libfoo.so.1.2.3</tt>, where the soname of the library is
3728 <tt>libfoo.so.1</tt>, and the first version of the package
3729 which contained a minor number of at least <tt>2.3</tt> was
3730 <var>1.2.3-1</var>, then the package's <var>shlibs</var>
3733 libfoo 1 foo (>= 1.2.3-1)
3738 The version-specific dependency is to avoid warnings from
3739 <prgn>ld.so</prgn> about using older shared libraries with
3743 <sect><heading>Further Technical information on
3744 <tt>shlibs</tt></heading>
3746 <sect1><heading><em>What</em> are the <tt>shlibs</tt> files?
3750 The <tt>debian/shlibs</tt> file provides a way of checking
3751 for shared library dependencies on packaged binaries.
3752 They are intended to be used by package maintainers to
3753 make their lives easier.
3757 Other <tt>shlibs</tt> files that exist on a Debian system are
3759 <item> <p><tt>/etc/dpkg/shlibs.default</tt></p></item>
3760 <item> <p><tt>/etc/dpkg/shlibs.override</tt></p></item>
3761 <item> <p><tt>/var/lib/dpkg/info/*.shlibs</tt></p></item>
3762 <item> <p><tt>debian/shlibs.local</tt></p></item>
3764 These files are used by <prgn>dpkg-shlibdeps</prgn> when
3765 creating a binary package.</p>
3768 <sect1><heading><em>How</em> does <prgn>dpkg-shlibdeps</prgn>
3772 <prgn>dpkg-shlibdeps</prgn>
3773 determines the shared libraries directly
3776 It used to do this by calling <prgn>ldd</prgn>, but it
3777 now calls <prgn>objdump</prgn> to do this. This
3778 requires a couple of changes in the way that packages
3782 A binary <tt>foo</tt> directly uses a library
3783 <tt>libbar</tt> if it is linked with that
3784 library. Other libraries that are needed by
3785 <tt>libbar</tt> are linked indirectly to <tt>foo</tt>,
3786 and the dynamic linker will load them automatically
3787 when it loads <tt>libbar</tt>. Running<prgn>ldd</prgn>
3788 lists all of the libraries used, both directly and
3789 indirectly; but <prgn>objdump</prgn> only lists the
3790 directly linked libraries. A package only needs to
3791 depend on the libraries it is directly linked to,
3792 since the dependencies for those libraries should
3793 automatically pull in the other libraries.
3796 This change does mean a change in the way packages are
3797 build though: currently <prgn>dpkg-shlibdeps</prgn> is
3798 only run on binaries. But since we will now rely on the
3799 libraries depending on the libraries they themselves
3800 need, the packages containing those libraries will
3801 need to run <prgn>dpkg-shlibdeps</prgn> on the
3805 A good example where this would help us is the current
3806 mess with multiple version of the <tt>mesa</tt>
3807 library. With the <prgn>ldd</prgn>-based system, every
3808 package that uses <tt>mesa</tt> needs to add a
3809 dependency on <tt>svgalib|svgalib-dummy</tt> in order
3810 to handle the glide <tt>mesa</tt> variant. With an
3811 <prgn>objdump</prgn>-based system this isn't necessary
3812 anymore and would have saved everyone a lot of work.
3815 Another example: we could update <tt>libimlib</tt>
3816 with a new version that supports a new graphics format
3817 called dgf. If we use the old <prgn>ldd</prgn> method,
3818 every package that uses <tt>libimlib</tt> would need
3819 to be recompiled so it would also depend on
3820 <tt>libdgf</tt> or it wouldn't run due to missing
3821 symbols. However with the new system, packages using
3822 <tt>libimlib</tt> can rely on <tt>libimlib</tt> itself
3823 having the dependency on <tt>libdgf</tt> and wouldn't
3827 used by the compiled binaries and libraries passed through
3828 on its command line.
3832 For each shared library linked to,
3833 <prgn>dpkg-shlibdeps</prgn> needs to know
3834 <list compact="compact">
3835 <item><p>the package containing the library, and</p></item>
3836 <item><p>the library version number,</p></item>
3838 and it scans the following files in this order:
3839 <enumlist compact="compact">
3840 <item><p><tt>debian/shlibs.local</tt></p></item>
3841 <item><p><tt>/etc/dpkg/shlibs.override</tt></p></item>
3842 <item><p><tt>/var/lib/dpkg/info/*.shlibs</tt></p></item>
3843 <item><p><tt>/etc/dpkg/shlibs.default</tt></p></item>
3848 <sect1><heading><em>Who</em> maintains the various
3849 <tt>shlibs</tt> files?
3853 <list compact="compact">
3855 <p><tt>/etc/dpkg/shlibs.default</tt> - the maintainer
3860 <tt>/var/lib/dpkg/info/<var>package</var>.shlibs</tt>
3861 - the maintainer of each package</p>
3865 <tt>/etc/dpkg/shlibs.override</tt> - the local
3866 system administrator</p>
3869 <p><tt>debian/shlibs.local</tt> - the maintainer of
3874 The <tt>shlibs.default</tt> file is managed by
3875 <prgn>dpkg</prgn>. The entries in <tt>shlibs.default</tt>
3876 that are provided by <prgn>dpkg</prgn> are just there to
3877 fix things until the shared library packages all have
3878 <tt>shlibs</tt> files.
3882 <sect1><heading><em>How</em> to use <prgn>dpkg-shlibdeps</prgn> and
3883 the <tt>shlibs</tt> files
3886 <sect2><heading>If your package doesn't provide a shared
3891 Put a call to <prgn>dpkg-shlibdeps</prgn> into your
3892 <tt>debian/rules</tt> file. If your package contains
3893 only binaries (e.g. no scripts) use:
3895 dpkg-shlibdeps debian/tmp/usr/bin/* debian/tmp/usr/sbin/*
3897 If <prgn>dpkg-shlibdeps</prgn> doesn't complain, you're
3898 done. If it does complain you might need to create your
3899 own <tt>debian/shlibs.local</tt> file.</p>
3902 <sect2><heading>If your package provides a shared library
3906 Create a <tt>debian/shlibs</tt> file and let
3907 <tt>debian/rules</tt> install it in the control area:
3909 install -m644 debian/shlibs debian/tmp/DEBIAN
3911 If your package contains additional binaries see above.
3916 <sect1><heading><em>How</em> to write
3917 <tt>debian/shlibs.local</tt>
3921 This file is intended only as a <em>temporary</em> fix if
3922 your binaries depend on a library which doesn't provide
3923 its own <tt>/var/lib/dpkg/info/*.shlibs</tt> file yet.
3927 Let's assume you are packaging a binary <tt>foo</tt>. Your
3928 output in building the package might look like this.
3931 libbar.so.1 => /usr/X11R6/lib/libbar.so.1.0 (0x4001e000)
3932 libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x4002c000)
3933 libc.so.6 => /lib/libc.so.6 (0x40114000)
3934 /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
3936 And when you ran <prgn>dpkg-shlibdeps</prgn>
3938 $ dpkg-shlibdeps -O foo
3939 dpkg-shlibdeps: warning: unable to find dependency information for shared library libbar
3940 (soname 1, path /usr/X11R6/lib/libbar.so.1.0, dependency field Depends)
3941 shlibs:Depends=libc6 (>= 2.2.1), xlibs (>= 4.0.1-11)
3943 The <prgn>foo</prgn> binary depends on the
3944 <prgn>libbar</prgn> shared library, but no package seems
3945 to provide a <tt>*.shlibs</tt> file in
3946 <tt>/var/lib/dpkg/info/</tt>. Let's determine the package
3952 $ dpkg -S /usr/X11R6/lib/libbar.so.1.0
3953 bar1: /usr/X11R6/lib/libbar.so.1.0
3954 $ dpkg -s bar1 | grep Version
3957 This tells us that the <prgn>bar1</prgn> package, version
3958 1.0-1 is the one we are using. Now we can create our own
3959 <tt>debian/shlibs.local</tt> to temporarily fix the above
3960 problem. Include the following line into your
3961 <tt>debian/shlibs.local</tt> file.
3963 libbar 1 bar1 (>= 1.0-1)
3965 Now your package build should work. As soon as the
3966 maintainer of <prgn>libbar1</prgn> provides a
3967 <tt>shlibs</tt> file, you can remove your
3968 <tt>debian/shlibs.local</tt> file.
3974 <chapt><heading>The Operating System</heading>
3978 <heading>File system hierarchy</heading>
3982 <heading>Linux File system Structure</heading>
3985 The location of all installed files and directories must
3986 comply with the Linux File system Hierarchy Standard
3987 (FHS). The latest version of this document can be found
3988 alongside this manual or on
3989 <url id="http://www.pathname.com/fhs/">.
3990 Specific questions about following the standard may be
3991 asked on <prgn>debian-devel</prgn>, or referred to Daniel
3992 Quinlan, the FHS coordinator, at
3993 <email>quinlan@pathname.com</email>.</p></sect1>
3997 <heading>Site-specific programs</heading>
4000 As mandated by the FHS, packages must not place any
4001 files in <tt>/usr/local</tt>, either by putting them in
4002 the file system archive to be unpacked by <prgn>dpkg</prgn>
4003 or by manipulating them in their maintainer scripts.</p>
4006 However, the package may create empty directories below
4007 <tt>/usr/local</tt> so that the system administrator knows
4008 where to place site-specific files. These directories
4009 should be removed on package removal if they are
4013 Note, that this applies only to directories <em>below</em>
4014 <tt>/usr/local</tt>, not <em>in</em>
4015 <tt>/usr/local</tt>. Packages must not create sub-directories
4016 in the directory <tt>/usr/local</tt> itself, except those listed in
4017 FHS, section 4.5. However, you may create directories
4018 below them as you wish. You must not remove any of the
4019 directories listed in 4.5, even if you created them.</p>
4022 Since <tt>/usr/local</tt> can be mounted read-only from a
4023 remote server, these directories must be created and
4024 removed by the <tt>postinst</tt> and <tt>prerm</tt>
4025 maintainer scripts. These scripts must not fail if either
4026 of these operations fail. (In the future, it will be
4027 possible to tell <prgn>dpkg</prgn> not to unpack files
4028 matching certain patterns, so that the directories can be
4029 included in the <tt>.deb</tt> packages and system
4030 administrators who do not wish these directories in
4031 /usr/local do not need to have them.)</p>
4034 For example, the <prgn>emacs</prgn> package will contain
4036 mkdir -p /usr/local/lib/emacs/site-lisp || true
4038 in the <tt>postinst</tt> script, and
4040 rmdir /usr/local/lib/emacs/site-lisp || true
4041 rmdir /usr/local/lib/emacs || true
4043 in the <tt>prerm</tt> script.</p>
4046 If you do create a directory in <tt>/usr/local</tt> for
4047 local additions to a package, you should ensure that
4048 settings in <tt>/usr/local</tt> take precedence over the
4049 equivalents in <tt>/usr</tt>.</p>
4052 However, because '/usr/local' and its contents are for
4053 exclusive use of the local administrator, a package must
4054 not rely on the presence or absence of files or
4055 directories in '/usr/local' for normal operation.</p>
4058 The <tt>/usr/local</tt> directory itself and all the
4059 subdirectories created by the package should (by default) have
4060 permissions 2775 (group-writable and set-group-id) and be
4061 owned by <tt>root.staff</tt>.</p>
4064 <heading>The system-wide mail directory</heading>
4066 The system-wide mail directory is <tt>/var/mail</tt>. This
4067 directory is part of the base system and should not owned
4068 by any particular mail agents. The use of the old
4069 location <tt>/var/spool/mail</tt> is deprecated, even
4070 though the spool may still be physically located there.
4071 To maintain partial upgrade compatibility for systems
4072 which have <tt>/var/spool/mail</tt> as their physical mail
4073 spool, packages using <tt>/var/mail</tt> must depend on
4074 either <package>libc6</package> (>= 2.1.3-13), or on
4075 <package>base-files</package> (>= 2.2.0), or on later
4076 versions of either one of these packages.
4085 <heading>Users and groups</heading>
4088 The Debian system can be configured to use either plain or
4089 shadow passwords.</p>
4092 Some user ids (UIDs) and group ids (GIDs) are reserved
4093 globally for use by certain packages. Because some packages
4094 need to include files which are owned by these users or
4095 groups, or need the ids compiled into binaries, these ids
4096 must be used on any Debian system only for the purpose for
4097 which they are allocated. This is a serious restriction, and
4098 we should avoid getting in the way of local administration
4099 policies. In particular, many sites allocate users and/or
4100 local system groups starting at 100.</p>
4103 Apart from this we should have dynamically allocated ids,
4104 which should by default be arranged in some sensible
4105 order--but the behavior should be configurable.</p>
4108 Packages other than <tt>base-passwd</tt> must not modify
4109 <tt>/etc/passwd</tt>, <tt>/etc/shadow</tt>,
4110 <tt>/etc/group</tt> or <tt>/etc/gshadow</tt>.</p>
4113 The UID and GID ranges are as follows:
4118 Globally allocated by the Debian project, the
4119 same on every Debian system. These ids will appear in
4120 the <tt>passwd</tt> and <tt>group</tt> files of all
4121 Debian systems, new ids in this range being added
4122 automatically as the <tt>base-passwd</tt> package is
4126 Packages which need a single statically allocated uid
4127 or gid should use one of these; their maintainers
4128 should ask the <tt>base-passwd</tt> maintainer for
4135 Dynamically allocated system users and groups.
4136 Packages which need a user or group, but can have this
4137 user or group allocated dynamically and differently on
4138 each system, should use `<tt>adduser --system</tt>' to
4139 create the group and/or user. <prgn>adduser</prgn>
4140 will check for the existence of the user or group, and
4141 if necessary choose an unused id based on the ranges
4142 specified in <tt>adduser.conf</tt>.</p></item>
4145 <tag>1000-29999:</tag>
4148 Dynamically allocated user accounts. By default
4149 <prgn>adduser</prgn> will choose UIDs and GIDs for
4150 user accounts in this range, though
4151 <tt>adduser.conf</tt> may be used to modify this
4155 <tag>30000-59999:</tag>
4157 <p>Reserved.</p></item>
4160 <tag>60000-64999:</tag>
4163 Globally allocated by the Debian project, but only
4164 created on demand. The ids are allocated centrally and
4165 statically, but the actual accounts are only created
4166 on users' systems on demand.</p>
4169 These ids are for packages which are obscure or which
4170 require many statically-allocated ids. These packages
4171 should check for and create the accounts in
4172 <tt>/etc/passwd</tt> or <tt>/etc/group</tt> (using
4173 <prgn>adduser</prgn> if it has this facility) if
4174 necessary. Packages which are likely to require
4175 further allocations should have a `hole' left after
4176 them in the allocation, to give them room to
4180 <tag>65000-65533:</tag>
4182 <p>Reserved.</p></item>
4187 <p>User `<tt>nobody</tt>.' The corresponding gid refers
4188 to the group `<tt>nogroup</tt>.'</p></item>
4194 <tt>(uid_t)(-1) == (gid_t)(-1)</tt>. NOT TO BE USED,
4195 because it is the error return sentinel value.</p>
4200 <sect id="sysvinit">
4201 <heading>System run levels</heading>
4204 <sect1 id="/etc/init.d">
4205 <heading>Introduction</heading>
4208 The <tt>/etc/init.d</tt> directory contains the scripts
4209 executed by <prgn>init</prgn> at boot time and when init
4210 state (or `runlevel') is changed (see <manref name="init"
4214 There are at least two different, yet functionally
4215 equivalent, ways of handling these scripts. For the sake
4216 of simplicity, this document describes only the symbolic
4217 link method. However, it must not be assumed by maintainer
4218 scripts that this method is being used, and any automated
4219 manipulation of the various runlevel behaviours by
4220 maintainer scripts must be performed using `update-rc.d'
4221 as described below and not by manually installing or
4222 removing symlinks. For information on the
4223 implementation details of the other method, implemented in
4224 the <tt>file-rc</tt> package, please refer to the
4225 documentation of that package.</p>
4228 These scripts are referenced by symbolic links in
4229 the <tt>/etc/rc<var>n</var>.d</tt> directories. When
4230 changing runlevels, <prgn>init</prgn> looks in the
4231 directory <tt>/etc/rc<var>n</var>.d</tt> for the scripts
4232 it should execute, where <var>n</var> is the runlevel that
4233 is being changed to, or `S' for the boot-up scripts.</p>
4236 The names of the links all have the form
4237 <tt>S<var>mm</var><var>script</var></tt> or
4238 <tt>K<var>mm</var><var>script</var></tt> where
4239 <var>mm</var> is a two-digit number and <var>script</var>
4240 is the name of the script (this should be the same as the
4241 name of the actual script in <tt>/etc/init.d</tt>.</p>
4244 When <prgn>init</prgn> changes runlevel first the targets
4245 of the links whose names starting with a <tt>K</tt> are
4246 executed, each with the single argument <tt>stop</tt>,
4247 followed by the scripts prefixed with an <tt>S</tt>, each
4248 with the single argument <tt>start</tt>. The <tt>K</tt>
4249 links are responsible for killing services and the
4250 <tt>S</tt> link for starting services upon entering the
4254 For example, if we are changing from runlevel 2 to
4255 runlevel 3, init will first execute all of the <tt>K</tt>
4256 prefixed scripts it finds in <tt>/etc/rc3.d</tt>, and then
4257 all of the <tt>S</tt> prefixed scripts. The links
4258 starting with <tt>K</tt> will cause the referred-to file
4259 to be executed with an argument of <tt>stop</tt>, and the
4260 <tt>S</tt> links with an argument of <tt>start</tt>.</p>
4263 The two-digit number <var>mm</var> is used to decide which
4264 order to start and stop things in--low-numbered links have
4265 their scripts run first. For example, the <tt>K20</tt>
4266 scripts will be executed before the <tt>K30</tt> scripts.
4267 This is used when a certain service must be started before
4268 another. For example, the name server <prgn>bind</prgn>
4269 might need to be started before the news server
4270 <prgn>inn</prgn> so that <prgn>inn</prgn> can set up its
4271 access lists. In this case, the script that starts
4272 <prgn>bind</prgn> would have a lower number than the
4273 script that starts <prgn>inn</prgn> so that it runs first:
4282 <heading>Writing the scripts</heading>
4285 Packages that include daemons for system services should
4286 place scripts in <tt>/etc/init.d</tt> to start or stop
4287 services at boot time or during a change of runlevel.
4288 These scripts should be named
4289 <tt>/etc/init.d/<var>package</var></tt>, and they should
4290 accept one argument, saying what to do:
4293 <tag><tt>start</tt></tag>
4294 <item><p>start the service,</p></item>
4296 <tag><tt>stop</tt></tag>
4297 <item><p>stop the service,</p></item>
4299 <tag><tt>restart</tt></tag>
4300 <item><p>stop and restart the service,</p></item>
4302 <tag><tt>reload</tt></tag>
4303 <item><p>cause the configuration of the service to be
4304 reloaded without actually stopping and restarting
4305 the service,</p></item>
4307 <tag><tt>force-reload</tt></tag> <item><p>cause the
4308 configuration to be reloaded if the service supports
4309 this, otherwise restart the service.</p></item>
4312 The <tt>start</tt>, <tt>stop</tt>, <tt>restart</tt>, and
4313 <tt>force-reload</tt> options should be supported by all
4314 scripts in <tt>/etc/init.d</tt>, the <tt>reload</tt>
4315 option is optional.</p>
4318 The <tt>init.d</tt> scripts should ensure that they will
4319 behave sensibly if invoked with <tt>start</tt> when the
4320 service is already running, or with <tt>stop</tt> when it
4321 isn't, and that they don't kill unfortunately-named user
4322 processes. The best way to achieve this is usually to use
4323 <prgn>start-stop-daemon</prgn>.</p>
4326 If a service reloads its configuration automatically (as
4327 in the case of <prgn>cron</prgn>, for example), the
4328 <tt>reload</tt> option of the <tt>init.d</tt> script
4329 should behave as if the configuration has been reloaded
4333 These scripts should not fail obscurely when the
4334 configuration files remain but the package has been
4335 removed, as configuration files remain on the system after
4336 the package has been removed. Only when <prgn>dpkg</prgn>
4337 is executed with the <tt>--purge</tt> option will
4338 configuration files be removed. In particular, the init
4339 script itself is usually a configuration file (see
4340 <ref id="init.d notes">), and will remain on the system if
4341 the package is removed but not purged. Therefore, you
4342 should include a <tt>test</tt> statement at the top of the
4345 test -f <var>program-executed-later-in-script</var> || exit 0
4349 Often there are some values in the `<tt>init.d</tt>'
4350 scripts that a system administrator will frequently want
4351 to change. While the scripts are frequently conffiles,
4352 modifying them requires that the administrator merge in
4353 their changes each time the package is upgraded and the
4354 conffile changes. To ease the burden on the system
4355 administrator, such configurable values should not be
4356 placed directly in the script. Instead, they should be
4357 placed in a file in `<tt>/etc/default</tt>', which
4358 typically will have the same base name as the
4359 `<tt>init.d</tt>' script. This extra file can be sourced
4360 by the script when the script runs. It must contain only
4361 variable settings and comments.
4365 To ensure that vital configurable values are always
4366 available, the `<tt>init.d</tt>' script should set default
4367 values for each of the shell variables it uses before
4368 sourcing the <tt>/etc/default/</tt> file. Also, since the
4369 `<tt>/etc/default/</tt>' file is often a conffile, the
4370 `<tt>init.d</tt>' script must behave sensibly without
4371 failing if it is deleted.
4377 <heading>Managing the links</heading>
4380 The program <prgn>update-rc.d</prgn> is provided to make
4381 it easier for package maintainers to arrange for the
4382 proper creation and removal of
4383 <tt>/etc/rc<var>n</var>.d</tt> symbolic links, or their
4384 functional equivalent if another method is being used.
4385 This may be used by maintainers in their packages'
4386 <tt>postinst</tt> and <tt>postrm</tt> scripts.</p>
4389 You must use this script to make changes to
4390 <tt>/etc/rc<var>n</var>.d</tt> and <em>never</em> either
4391 include any <tt>/etc/rc<var>n</var>.d</tt> symbolic links
4392 in the actual archive or manually create or remove the
4393 symbolic links in maintainer scripts. (The latter will
4394 fail if an alternative method of maintaining runlevel
4395 information is being used.)</p>
4398 By default <prgn>update-rc.d</prgn> will start services in
4399 each of the multi-user state runlevels (2, 3, 4, and 5)
4400 and stop them in the halt runlevel (0), the single-user
4401 runlevel (1) and the reboot runlevel (6). The system
4402 administrator will have the opportunity to customize
4403 runlevels by either running <prgn>update-rc.d</prgn>, by
4404 simply adding, moving, or removing the symbolic links in
4405 <tt>/etc/rc<var>n</var>.d</tt> if symbolic links are being
4406 used, or by modifying <tt>/etc/runlevel.conf</tt> if the
4407 <tt>file-rc</tt> method is being used.</p>
4410 To get the default behavior for your package, put in your
4411 <tt>postinst</tt> script
4413 update-rc.d <var>package</var> defaults >/dev/null
4415 and in your <tt>postrm</tt>
4417 if [ purge = "$1" ]; then
4418 update-rc.d <var>package</var> remove >/dev/null
4423 This will use a default sequence number of 20. If it does
4424 not matter when or in which order the script is run, use
4425 this default. If it does, then you should talk to the
4426 maintainer of the <prgn>sysvinit</prgn> package or post to
4427 <tt>debian-devel</tt>, and they will help you choose a
4431 For more information about using <tt>update-rc.d</tt>,
4432 please consult its manpage <manref name="update-rc.d"
4433 section="8">.</p></sect1>
4437 <heading>Boot-time initialization</heading>
4440 There used to be another directory, <tt>/etc/rc.boot</tt>,
4441 which contained scripts which were run once per machine
4442 boot. This has been deprecated in favour of links from
4443 <tt>/etc/rcS.d</tt> to files in <tt>/etc/init.d</tt> as
4444 described in <ref id="/etc/init.d">. Packages must not
4445 place files in <tt>/etc/rc.boot</tt>.</p>
4447 <sect1 id="init.d notes">
4448 <heading>Notes</heading>
4451 <em>Do not</em> include the
4452 <tt>/etc/rc<var>n</var>.d/*</tt> symbolic links in the
4453 <tt>.deb</tt> file system archive! <em>This will cause
4454 problems!</em> You must create them with
4455 <prgn>update-rc.d</prgn>, as above.</p>
4458 <em>Do not</em> include the
4459 <tt>/etc/rc<var>n</var>.d/*</tt> symbolic links in
4460 <prgn>dpkg</prgn>'s conffiles list! <em>This will cause
4461 problems!</em> You should, however, treat the
4462 <tt>/etc/init.d</tt> scripts as configuration files,
4463 either by marking them as conffiles or managing them
4464 correctly in the maintainer scripts (see
4465 <ref id="config files">). (This is important since we want
4466 to give the local system administrator the chance to adapt
4467 the scripts to the local system--e.g., to disable a
4468 service without de-installing the package, or to specify
4469 some special command line options when starting a
4470 service--while making sure her changes aren't lost during
4471 the next package upgrade.)</p>
4475 <heading>Example</heading>
4478 The <prgn>bind</prgn> DNS (nameserver) package wants to
4479 make sure that the nameserver is running in multiuser
4480 runlevels, and is properly shut down with the system. It
4481 puts a script in <tt>/etc/init.d</tt>, naming the script
4482 appropriately <tt>bind</tt>. As you can see, the script
4483 interprets the argument <tt>reload</tt> to send the
4484 nameserver a <tt>HUP</tt> signal (causing it to reload its
4485 configuration); this way the user can say
4486 <tt>/etc/init.d/bind reload</tt> to reload the name
4487 server. The script has one configurable value, which can
4488 be used to pass parameters to the named program at
4496 # Original version by Robert Leslie
4497 # <rob@mars.org>, edited by iwj and cs
4499 test -x /usr/sbin/named || exit 0
4501 # Source defaults file.
4503 if [ -f /etc/default/bind ]; then
4510 echo -n "Starting domain name service: named"
4511 start-stop-daemon --start --quiet --exec /usr/sbin/named \
4516 echo -n "Stopping domain name service: named"
4517 start-stop-daemon --stop --quiet \
4518 --pidfile /var/run/named.pid --exec /usr/sbin/named
4522 echo -n "Restarting domain name service: named"
4523 start-stop-daemon --stop --quiet \
4524 --pidfile /var/run/named.pid --exec /usr/sbin/named
4525 start-stop-daemon --start --verbose --exec /usr/sbin/named \
4529 force-reload|reload)
4530 echo -n "Reloading configuration of domain name service: named"
4531 start-stop-daemon --stop --signal 1 --quiet \
4532 --pidfile /var/run/named.pid --exec /usr/sbin/named
4536 echo "Usage: /etc/init.d/bind {start|stop|restart|reload|force-reload}" >&2
4546 Complementing the above init script is a file
4547 '<tt>/etc/default/bind</tt>', which contains configurable
4548 parameters used by the script.
4552 # Specified parameters to pass to named. See named(8).
4553 # You may uncomment the following line, and edit to taste.
4559 Another example on which to base your <tt>/etc/init.d</tt>
4560 scripts is in <tt>/etc/init.d/skeleton</tt>.</p>
4563 If this package is happy with the default setup from
4564 <prgn>update-rc.d</prgn>, namely an ordering number of 20
4565 and having named running in all runlevels, it can say in
4566 its <tt>postinst</tt>:
4568 update-rc.d bind defaults >/dev/null
4570 And in its <tt>postrm</tt>, to remove the links when the
4573 if [ purge = "$1" ]; then
4574 update-rc.d bind remove >/dev/null
4580 <heading>Cron jobs</heading>
4583 Packages must not modify the configuration file
4584 <tt>/etc/crontab</tt>, and they must not modify the files in
4585 <tt>/var/spool/cron/crontabs</tt>.</p>
4588 If a package wants to install a job that has to be executed
4589 via cron, it should place a file with the name of the
4590 package in one of the following directories:
4596 As these directory names imply, the files within them are
4597 executed on a daily, weekly, or monthly basis,
4598 respectively. The exact times are listed in
4599 <tt>/etc/crontab</tt>.</p>
4602 All files installed in any of these directories must be
4603 scripts (shell scripts, Perl scripts, etc.) so that they can
4604 easily be modified by the local system administrator. In
4605 addition, they should be treated as configuration files.</p>
4608 If a certain job has to be executed more frequently than
4609 daily, the package should install a file
4610 <tt>/etc/cron.d/<var>package-name</var></tt>. This file uses
4611 the same syntax as <tt>/etc/crontab</tt> and is processed by
4612 <prgn>cron</prgn> automatically. The file must also be
4613 treated as a configuration file. (Note, that entries in the
4614 <tt>/etc/cron.d</tt> directory are not handled by
4615 <prgn>anacron</prgn>. Thus, you should only use this
4616 directory for jobs which may be skipped if the system is not
4620 The scripts or crontab entries in these directories should
4621 check if all necessary programs are installed before they
4622 try to execute them. Otherwise, problems will arise when a
4623 package was removed but not purged since configuration files
4624 are kept on the system in this situation.</p>
4628 <heading>Console messages</heading>
4631 This section describes different formats for messages
4632 written to standard output by the <tt>/etc/init.d</tt>
4633 scripts. The intent is to improve the consistency of
4634 Debian's startup and shutdown look and feel.</p>
4637 Please look very careful at the details. We want to get the
4638 messages to look exactly the same way concerning spaces,
4639 punctuation, and case of letters.</p>
4642 Here is a list of overall rules that you should use when you
4643 create output messages. They can be useful if you have a
4644 non-standard message that isn't covered in the sections
4651 Every message should cover one line, start with a
4652 capital letter and end with a period `.'.</p></item>
4657 If you want to express that the computer is working on
4658 something (performing a specific task, not starting or
4659 stopping a program), we use an ``ellipsis'', namely
4660 three dots `...'. Note that we don't insert spaces in
4661 front of or behind the dots. If the task has been
4662 completed we write `done.' and a line feed.</p></item>
4667 Design your messages as if the computer is telling you
4668 what he is doing (let him be polite :-) but don't
4669 mention ``him'' directly. For example, if you think
4672 I'm starting network daemons: nfsd mountd.
4676 Starting network daemons: nfsd mountd.
4677 </example></p></item>
4681 The following formats should be used</p>
4686 <p>when daemons get started.</p>
4689 Use this format if your script starts one or more
4690 daemons. The output should look like this (a single
4691 line, no leading spaces):
4693 Starting <description>: <daemon-1> <daemon-2> <...> <daemon-n>.
4695 The <description> should describe the subsystem
4696 the daemon or set of daemons are part of, while
4697 <daemon-1> up to <daemon-n> denote each
4698 daemon's name (typically the file name of the
4702 For example, the output of /etc/init.d/lpd would look like:
4704 Starting printer spooler: lpd.
4708 This can be achieved by saying
4710 echo -n "Starting printer spooler: lpd"
4711 start-stop-daemon --start --quiet lpd
4714 in the script. If you have more than one daemon to
4715 start, you should do the following:
4717 echo -n "Starting remote file system services:"
4718 echo -n " nfsd"; start-stop-daemon --start --quiet nfsd
4719 echo -n " mountd"; start-stop-daemon --start --quiet mountd
4720 echo -n " ugidd"; start-stop-daemon --start --quiet ugidd
4723 This makes it possible for the user to see what takes
4724 so long and when the final daemon has been
4725 started. You should be careful where to put spaces: In the
4726 example above the system administrator can easily
4727 comment out a line if he don't wants to start a
4728 specific daemon, while the displayed message still
4729 looks good.</p></item>
4733 <p>when something needs to be configured.</p>
4736 If you have to set up different parameters of the
4737 system upon boot up, you should use this format:
4739 Setting <parameter> to `<value>'.
4743 You can use the following echo statement to get the quotes right:
4745 echo "Setting DNS domainname to \`"value"'."
4749 Note that the left quotation mark (`) is different
4750 from the right (').</p></item>
4753 <p>when a daemon is stopped.</p>
4756 When you stop a daemon you should issue a message
4757 similar to the startup message, except that `Starting'
4758 is replaced with `Stopping'.</p>
4761 So stopping the printer daemon will like like this:
4763 Stopping printer spooler: lpd.
4764 </example></p></item>
4767 <p>when something is executed.</p>
4770 There are several examples where you have to run a
4771 program at system startup or shutdown to perform a
4772 specific task. For example, setting the system's clock
4773 via `netdate' or killing all processes when the system
4774 comes down. Your message should like this:
4776 Doing something very useful...done.
4778 You should print the `done.' right after the job has been completed,
4779 so that the user gets informed why he has to wait. You can get this
4782 echo -n "Doing something very useful..."
4786 in your script.</p></item>
4789 <p>when the configuration is reloaded.</p>
4792 When a daemon is forced to reload its configuration
4793 files you should use the following format:
4795 Reloading <daemon's-name> configuration...done.
4796 </example></p></item>
4799 <p>when none of the above rules apply.</p>
4802 If you have to print a message that doesn't fit into
4803 the styles described above, you can use something
4804 appropriate, but please have a look at the overall
4805 rules listed above.</p></item>
4810 <heading>Menus</heading>
4813 Menu entries should follow the current menu policy as
4814 defined in the file <ftpsite>ftp.debian.org</ftpsite> in
4815 <ftppath>/debian/doc/package-developer/menu-policy.txt.gz</ftppath>
4816 or your local mirror. In addition, it is included in the
4817 <tt>debian-policy</tt> package.
4821 The Debian <tt>menu</tt> packages provides a unique
4822 interface between packages providing applications and
4823 documents, and <em>menu programs</em> (either X window
4824 managers or text-based menu programs as
4825 <prgn>pdmenu</prgn>).</p>
4828 All packages that provide applications that need not be
4829 passed any special command line arguments for normal
4830 operation should register a menu entry for those
4831 applications, so that users of the <tt>menu</tt> package
4832 will automatically get menu entries in their window
4833 managers, as well in shells like <tt>pdmenu</tt>.</p>
4836 Please refer to the <em>Debian Menu System</em> document
4837 that comes with the <tt>menu</tt> package for information
4838 about how to register your applications and web
4844 <heading>Multimedia handlers</heading>
4847 Packages which provide the ability to view/show/play,
4848 compose, edit or print MIME types should register themselves
4849 as such following the current MIME support policy as defined
4850 in the file found on <ftpsite>ftp.debian.org</ftpsite> in
4851 <ftppath>/debian/doc/package-developer/mime-policy.txt.gz</ftppath>
4852 or your local mirror. In addition, it is included in the
4853 <tt>debian-policy</tt> package.
4857 MIME (Multipurpose Internet Mail Extensions, RFC 1521) is a
4858 mechanism for encoding files and data streams and providing
4859 meta-information about them, in particular their type (e.g.
4860 audio or video) and format (e.g. PNG, HTML, MP3).
4864 Registration of MIME type handlers allows programs like mail
4865 user agents and web browsers to to invoke these handlers to
4866 view, edit or display MIME types they don't support
4872 <heading>Keyboard configuration</heading>
4875 To achieve a consistent keyboard configuration (i.e., all
4876 applications interpret a keyboard event the same way) all
4877 programs in the Debian distribution must be configured to
4878 comply with the following guidelines.</p>
4881 Here is a list that contains certain keys and their interpretation:
4884 <tag><tt><--</tt></tag>
4885 <item><p>delete the character to the left of the cursor</p></item>
4887 <tag><tt>Delete</tt></tag>
4888 <item><p>delete the character to the right of the cursor</p></item>
4890 <tag><tt>Control+H</tt></tag>
4891 <item><p>emacs: the help prefix</p></item>
4894 The interpretation of any keyboard events should be independent
4895 of the terminal that's used, be it a virtual console, an X
4896 terminal emulator, an rlogin/telnet session, etc.</p>
4899 The following list explains how the different programs
4900 should be set up to achieve this:</p>
4903 <list compact="compact">
4904 <item><p>`<tt><--</tt>' generates KB_Backspace in
4907 <item><p>`<tt>Delete</tt>' generates KB_Delete in X.</p></item>
4911 X translations are set up to make KB_Backspace
4912 generate ASCII DEL, and to make KB_Delete generate
4913 <tt>ESC [ 3 ~</tt> (this is the vt220 escape code for
4914 the `delete character' key). This must be done by
4915 loading the resources using xrdb on all local X
4916 displays, not using the application defaults, so that
4917 the translation resources used correspond to the
4918 xmodmap settings.</p></item>
4922 The Linux console is configured to make
4923 `<tt><--</tt>' generate DEL, and `Delete' generate
4924 <tt>ESC [ 3 ~</tt> (this is the case at the
4928 X applications are configured so that Backspace
4929 deletes left, and Delete deletes right. Motif
4930 applications already work like this.</p></item>
4932 <item><p>stty erase <tt>^?</tt> .</p></item>
4935 The `xterm' terminfo entry should have <tt>ESC [ 3
4936 ~</tt> for kdch1, just like TERM=linux and
4937 TERM=vt220.</p></item>
4940 Emacs is programmed to map KB_Backspace or the `stty
4941 erase' character to delete-backward-char, and
4942 KB_Delete or kdch1 to delete-forward-char, and
4943 <tt>^H</tt> to help as always.</p></item>
4946 Other applications use the `stty erase' character and
4947 kdch1 for the two delete keys, with ASCII DEL being
4948 `delete previous character' and kdch1 being `delete
4949 character under cursor'.</p></item>
4953 This will solve the problem except for:</p>
4956 <list compact="compact">
4958 Some terminals have a <tt><--</tt> key that cannot
4959 be made to produce anything except <tt>^H</tt>. On
4960 these terminals Emacs help will be unavailable on
4961 <tt>^H</tt> (assuming that the `stty erase' character
4962 takes precedence in Emacs, and has been set
4963 correctly). M-x help or F1 (if available) can be used
4967 Some operating systems use <tt>^H</tt> for stty erase.
4968 However, modern telnet versions and all rlogin
4969 versions propagate stty settings, and almost all UNIX
4970 versions honour stty erase. Where the stty settings
4971 are not propagated correctly things can be made to
4972 work by using stty manually.</p></item>
4975 Some systems (including previous Debian versions) use
4976 xmodmap to arrange for both <tt><--</tt> and Delete
4977 to generate KB_Delete. We can change the behavior
4978 of their X clients via the same X resources that we
4979 use to do it for our own, or have our clients be
4980 configured via their resources when things are the
4981 other way around. On displays configured like this
4982 Delete will not work, but <tt><--</tt>
4986 Some operating systems have different kdch1 settings
4987 in their terminfo for xterm and others. On these
4988 systems the Delete key will not work correctly when
4989 you log in from a system conforming to our policy, but
4990 <tt><--</tt> will.</p></item>
4997 <heading>Environment variables</heading>
5000 A program must not depend on environment variables to get
5001 reasonable defaults. (That's because these environment
5002 variables would have to be set in a system-wide
5003 configuration file like /etc/profile, which is not supported
5007 If a program usually depends on environment variables for its
5008 configuration, the program should be changed to fall back to
5009 a reasonable default configuration if these environment
5010 variables are not present. If this cannot be done easily
5011 (e.g., if the source code of a non-free program is not
5012 available), the program must be replaced by a small
5013 `wrapper' shell script which sets the environment variables
5014 if they are not already defined, and calls the original program.</p>
5017 Here is an example of a wrapper script for this purpose:
5021 BAR=${BAR:-/var/lib/fubar}
5023 exec /usr/lib/foo/foo "$@"
5027 Furthermore, as <tt>/etc/profile</tt> is a configuration
5028 file of the <prgn>base-files</prgn> package, other packages must not
5029 put any environment variables or other commands into that
5034 <heading>Files</heading>
5038 <heading>Binaries</heading>
5041 Two different packages must not install programs with
5042 different functionality but with the same filenames. (The
5043 case of two programs having the same functionality but
5044 different implementations is handled via `alternatives.')
5045 If this case happens, one of the programs must be
5046 renamed. The maintainers should report this to the
5047 developers' mailing and try to find a consensus about
5048 which package will have to be renamed. If a consensus can
5049 not be reached, <em>both</em> programs must be
5053 Generally the following compilation parameters should be used:
5056 CFLAGS = -O2 -Wall # sane warning options vary between programs
5058 install -s # (or use strip on the files in debian/tmp)
5062 Note that by default all installed binaries should be stripped,
5063 either by using the <tt>-s</tt> flag to
5064 <prgn>install</prgn>, or by calling <prgn>strip</prgn> on
5065 the binaries after they have been copied into
5066 <tt>debian/tmp</tt> but before the tree is made into a
5070 The <tt>-N</tt> flag should not be used. On a.out systems
5071 it may have been useful for some very small binaries, but
5072 for ELF it has no good effect.</p>
5075 Debugging symbols are useful for error diagnosis,
5076 investigation of core dumps (which may be submitted by users
5077 in bug reports), or testing and developing the
5078 software. Therefore it is recommended to support building
5079 the package with debugging information through the following
5080 interface: If the environment variable
5081 <tt>DEB_BUILD_OPTIONS</tt> contains the string
5082 <tt>debug</tt>, compile the software with debugging
5083 information (usually this involves adding the <tt>-g</tt>
5084 flag to <tt>CFLAGS</tt>). This allows the generation of a
5085 build tree with debugging information. If the environment
5086 variable <tt>DEB_BUILD_OPTIONS</tt> contains the string
5087 <tt>nostrip</tt>, do not strip the files at installation
5088 time. This allows one to generate a package with debugging
5089 information included. The following makefile snippet is only
5090 an example of how one may test for either condition:
5093 Rationale: Building by default with -g causes more
5094 wasted CPU cycles since the information is stripped away
5095 anyway. The package can by default build without -g if
5096 it also provides a mechanism to easily be rebuilt with
5097 debugging information. This can be done by providing a
5098 "build-debug" make target, or allowing the user to
5099 specify "DEB_BUILD_OPTIONS=debug" in the environment while
5100 compiling that package.
5102 <p>Now this has several added benefits:
5106 It is actually easier to build debugging bins and
5107 libraries this way (no more editing debian/rules
5108 or similar) since it provides a documented way of
5109 getting this type of build.</p>
5113 There will be much less wasted CPU time for the
5114 autobuilders since not having debugging
5115 information (and hence also not having to strip
5116 it) will increase the speed of compiles. This
5117 skips an entire pass of the compiler.
5128 INSTALL_FILE = $(INSTALL) -p -o root -g root -m 644
5129 INSTALL_PROGRAM = $(INSTALL) -p -o root -g root -m 755
5130 INSTALL_SCRIPT = $(INSTALL) -p -o root -g root -m 755
5131 INSTALL_DIR = $(INSTALL) -p -d -o root -g root -m 755
5133 ifneq (,$(findstring debug,$(DEB_BUILD_OPTIONS)))
5136 ifeq (,$(findstring nostrip,$(DEB_BUILD_OPTIONS)))
5137 INSTALL_PROGRAM += -s
5141 Please note that the above example is merely informative,
5142 and is not a policy mandate. You may have to massage this
5143 example in order to make it work for your package.
5148 It is up to the package maintainer to decide what
5149 compilation options are best for the package. Certain
5150 binaries (such as computationally-intensive programs) will
5151 function better with certain flags (<tt>-O3</tt>, for
5152 example); feel free to use them. Please use good judgment
5153 here. Don't use flags for the sake of it; only use them
5154 if there is good reason to do so. Feel free to override
5155 the upstream author's ideas about which compilation
5156 options are best--they are often inappropriate for our
5157 environment.</p></sect>
5161 <heading>Libraries</heading>
5164 All libraries must have a shared version in the lib
5165 package and a static version in the lib-dev package. The
5166 shared version must be compiled with <tt>-fPIC</tt>, and
5167 the static version must not be. In other words, each
5168 <tt>*.c</tt> file will need to be compiled twice.</p>
5171 You must specify the gcc option <tt>-D_REENTRANT</tt>
5172 when building a library (either static or shared) to make
5173 the library compatible with LinuxThreads.</p>
5176 Note that all installed shared libraries should be
5179 strip --strip-unneeded <your-lib>
5181 (The option `--strip-unneeded' makes <tt>strip</tt> remove
5182 only the symbols which aren't needed for relocation
5183 processing.) Shared libraries can function perfectly well
5184 when stripped, since the symbols for dynamic linking are
5185 in a separate part of the ELF object file.</p>
5188 Note that under some circumstances it may be useful to
5189 install a shared library unstripped, for example when
5190 building a separate package to support debugging.
5194 An ever increasing number of packages are using libtool to
5195 do their linking. The latest GNU libtools (>= 1.3a) can take
5196 advantage of the metadata in the installed libtool archive
5197 files (`*.la'). The main advantage of libtool's .la files is
5198 that it allows libtool to store and subsequently access
5199 metadata with respect to the libraries it builds. libtool
5200 will search for those files, which contain a lot of useful
5201 information about a library (e.g. dependency libraries for
5202 static linking). Also, they're <em>essential</em> for
5203 programs using libltdl.
5207 Certainly libtool is fully capable of linking against shared
5208 libraries which don't have .la files, but being a mere shell
5209 script it can add considerably to the build time of a
5210 libtool using package if that shell-script has to derive all
5211 this information from first principles for each library every
5212 time it is linked. With the advent of libtool-1.4 (and to a
5213 lesser extent libtool-1.3), the .la files will also store
5214 information about inter-library dependencies which cannot
5215 necessarily be derived after the .la file is deleted.
5219 Packages that use libtool to create shared libraries should
5220 include the <em>.la</em> files in the <em>-dev</em>
5221 packages, with the exception that if the package relies on
5222 libtool's <em>libltdl</em> library, in which case the .la
5223 files must go in the run-time library package. This is a
5224 good idea in general, and especially for static linking
5229 You must make sure that you use only released versions of
5230 shared libraries to build your packages; otherwise other
5231 users will not be able to run your binaries
5232 properly. Producing source packages that depend on
5233 unreleased compilers is also usually a bad
5240 <heading>Shared libraries</heading>
5243 Packages involving shared libraries should be split up
5244 into several binary packages.</p>
5247 For a straightforward library which has a development
5248 environment and a runtime kit including just shared
5249 libraries you need to create two packages:
5250 <tt><var>libraryname</var><var>soname</var></tt>
5251 (<var>soname</var> is the shared object name of the shared
5252 library--it's the thing that has to match exactly between
5253 building an executable and running it for the dynamic
5254 linker to be able run the program; usually the
5255 <var>soname</var> is the major number of the library) and
5256 <tt><var>libraryname</var><var>soname</var>-dev</tt>.</p>
5259 If you prefer only to support one development version at a
5260 time you may name the development package
5261 <tt><var>libraryname</var>-dev</tt>; otherwise you may
5262 wish to use <prgn>dpkg</prgn>'s conflicts mechanism to
5263 ensure that the user only installs one development version
5264 at a time (after all, different development versions are
5265 likely to have the same header files in them, causing a
5266 filename clash if both are installed). Typically the
5267 development version should also have an exact version
5268 dependency on the runtime library, to make sure that
5269 compilation and linking happens correctly.</p>
5272 Packages which use the shared library should have a
5273 dependency on the name of the shared library package,
5274 <tt><var>libraryname</var><var>soname</var></tt>. When
5275 the <var>soname</var> changes you can have both versions
5276 of the library installed while moving from the old library
5280 If your package has some run-time support programs which
5281 use the shared library you must not put them in
5282 the shared library package. If you do that then you won't
5283 be able to install several versions of the shared library
5284 without getting filename clashes. Instead, either create
5285 a third package for the runtime binaries (this package
5286 might typically be named
5287 <tt><var>libraryname</var>-runtime</tt>--note the absence
5288 of the <var>soname</var> in the package name) or if the
5289 development package is small include them in there.</p>
5292 If you have several shared libraries built from the same
5293 source tree you may lump them all together into a single
5294 shared library package, provided that you change all their
5295 <var>soname</var>s at once (so that you don't get filename
5296 clashes if you try to install different versions of the
5297 combined shared libraries package).</p>
5300 You should follow the directions in the <em>Debian Packaging
5301 Manual</em> (or other documentation of the Debian
5302 packaging tools) for putting the shared library in its
5303 package, and you must include a <tt>shlibs</tt> control area
5304 file with details of the dependencies for packages which use
5308 Shared libraries should not be installed
5309 executable, since <prgn>ld.so</prgn> does not require this
5310 and trying to execute a shared library results in a core
5315 <heading>Scripts</heading>
5318 All command scripts, including the package maintainer
5319 scripts inside the package and used by <prgn>dpkg</prgn>,
5320 should have a <tt>#!</tt> line naming the shell to be used
5321 to interpret them.</p>
5324 In the case of Perl scripts this should be
5325 <tt>#!/usr/bin/perl</tt>.</p>
5328 Shell scripts (<prgn>sh</prgn> and <prgn>bash</prgn>)
5329 should almost certainly start with <tt>set -e</tt> so that
5330 errors are detected. Every script should use
5331 <tt>set -e</tt> or check the exit status of <em>every</em>
5335 The standard shell interpreter `<tt>/bin/sh</tt>' can be a
5336 symbolic link to any POSIX compatible shell, if <tt>echo
5337 -n</tt> does not generate a newline.
5340 Debian policy specifies POSIX behavior for /bin/sh, but
5341 echo -n has widespread use in the Linux community
5342 (including especially debian policy, the linux kernel
5343 source, many debian scripts, etc.). This echo -n
5344 mechanism is valid but not required under POSIX, hence
5345 this explicit addition. Also, rumour has it that this
5346 shall be mandated under the LSB anyway.
5350 specifying `<tt>/bin/sh</tt>' as interpreter should only
5351 use POSIX features. If a script requires non-POSIX
5352 features from the shell interpreter, the appropriate shell
5353 must be specified in the first line of the script (e.g.,
5354 `<tt>#!/bin/bash</tt>') and the package must depend on the
5355 package providing the shell (unless the shell package is
5356 marked `Essential', e.g., in the case of
5361 You may wish to restrict your script to POSIX features when possible so
5362 that it may use <tt>/bin/sh</tt> as its interpreter. If
5363 your script works with <prgn>ash</prgn>, it's probably
5364 POSIX compliant, but if you are in doubt, use
5365 <tt>/bin/bash</tt>.</p>
5368 Perl scripts should check for errors when making any
5369 system calls, including <tt>open</tt>, <tt>print</tt>,
5370 <tt>close</tt>, <tt>rename</tt> and <tt>system</tt>.</p>
5373 <prgn>csh</prgn> and <prgn>tcsh</prgn> should be avoided
5374 as scripting languages. See <em>Csh Programming
5375 Considered Harmful</em>, one of the <tt>comp.unix.*</tt>
5376 FAQs. It can be found on
5377 <url id="http://language.perl.com/versus/csh.whynot">, or
5378 <url id="http://www.cpan.org/doc/FMTEYEWTK/versus/csh.whynot">
5379 or even on <ftpsite>ftp.cpan.org</ftpsite>
5380 <ftppath>/pub/perl/CPAN/doc/FMTEYEWTK/versus/csh.whynot</ftppath>.
5381 If an upstream package comes with <prgn>csh</prgn> scripts
5382 then you must make sure that they start with
5383 <tt>#!/bin/csh</tt> and make your package depend on the
5384 <prgn>c-shell</prgn> virtual package.</p>
5387 Any scripts which create files in world-writeable
5388 directories (e.g., in <tt>/tmp</tt>) must use a
5389 mechanism which will fail if a file with the same name
5393 The Debian base distribution provides the
5394 <prgn>tempfile</prgn> and <prgn>mktemp</prgn> utilities
5395 for use by scripts for this purpose.</p></sect>
5399 <heading>Symbolic links</heading>
5402 In general, symbolic links within a top-level directory
5403 should be relative, and symbolic links pointing from one
5404 top-level directory into another should be absolute. (A
5405 top-level directory is a sub-directory of the root
5409 In addition, symbolic links should be specified as short
5410 as possible, i.e., link targets like `foo/../bar' are
5414 Note that when creating a relative link using
5415 <prgn>ln</prgn> it is not necessary for the target of the
5416 link to exist relative to the working directory you're
5417 running <prgn>ln</prgn> from; nor is it necessary to
5418 change directory to the directory where the link is to be
5419 made. Simply include the string that should appear as the
5420 target of the link (this will be a pathname relative to
5421 the directory in which the link resides) as the first
5422 argument to <prgn>ln</prgn>.</p>
5425 For example, in your <prgn>Makefile</prgn> or
5426 <tt>debian/rules</tt>, do things like:
5428 ln -fs gcc $(prefix)/bin/cc
5429 ln -fs gcc debian/tmp/usr/bin/cc
5430 ln -fs ../sbin/sendmail $(prefix)/bin/runq
5431 ln -fs ../sbin/sendmail debian/tmp/usr/bin/runq
5435 A symbolic link pointing to a compressed file should
5436 always have the same file extension as the referenced
5437 file. (For example, if a file `<tt>foo.gz</tt>' is
5438 referenced by a symbolic link, the filename of the link
5439 has to end with `<tt>.gz</tt>' too, as in
5440 `bar.gz.')</p></sect>
5444 <heading>Device files</heading>
5447 Packages must not include device files in the package file
5451 If a package needs any special device files that are not
5452 included in the base system, it must call
5453 <prgn>MAKEDEV</prgn> in the <tt>postinst</tt> script,
5454 after asking the user for permission to do so.</p>
5457 Packages must not remove any device files in the
5458 <tt>postrm</tt> or any other script. This is left to the
5459 system administrator.</p>
5462 Debian uses the serial devices
5463 <tt>/dev/ttyS*</tt>. Programs using the old
5464 <tt>/dev/cu*</tt> devices should be changed to use
5465 <tt>/dev/ttyS*</tt>.</p>
5468 <sect id="config files">
5469 <heading>Configuration files</heading>
5471 <heading>Definitions</heading>
5474 <tag>configuration file</tag>
5476 A file that affects the operation of program, or
5477 provides site- or host-specific information, or
5478 otherwise customizes the behavior of program.
5479 Typically, configuration files are intended to be
5480 modified by the system administrator (if needed or
5481 desired) to conform to local policy or provide more
5482 useful site-specific behavior.</p>
5485 <tag><tt>conffile</tt></tag>
5487 A file listed in a package's <tt>conffiles</tt>
5488 file, and is treated specially by <prgn>dpkg</prgn>
5489 (see the <em>Debian Packaging Manual</em>).</p>
5495 The distinction between these two is important; they are
5496 not interchangeable concepts. Almost all
5497 <tt>conffiles</tt> are configuration files, but many
5498 configuration files are not <tt>conffiles</tt>.</p>
5501 Note that a script that embeds configuration information
5502 (such as most of the files in <tt>/etc/init.d</tt> and
5503 <tt>/etc/cron.{daily,weekly,monthly}</tt>) is de-facto a
5504 configuration file and should be treated as such.</p>
5508 <heading>Location</heading>
5510 Any configuration files created or used by your package
5511 must reside in <tt>/etc</tt>. If there are several you
5512 should consider creating a subdirectory of <tt>/etc</tt>
5513 named after your package.</p>
5516 If your package creates or uses configuration files
5517 outside of <tt>/etc</tt>, and it is not feasible to modify
5518 the package to use the <tt>/etc</tt>, you should still put
5519 the files in <tt>/etc</tt> and create symbolic links to
5520 those files from the location that the package
5525 <heading>Behavior</heading>
5527 Configuration file handling must conform to the following
5531 <p>local changes must be preserved during a package
5535 <p>configuration files must be preserved when the
5536 package is removed, and only deleted when the
5537 package is purged.</p>
5542 The easy way to achieve this behavior is to make the
5543 configuration file a <tt>conffile</tt>. This is
5544 appropriate only if it is possible to distribute a default
5545 version that will work for most installations, although
5546 some system administrators may choose to modify it. This
5547 implies that the default version will be part of the
5548 package distribution, and must not be modified by the
5549 maintainer scripts during installation (or at any other
5554 In order to ensure that local changes are preserved
5555 correctly, no package may contain or make hard links to
5559 Rationale: There are two problems with hard links.
5560 The first is that some editors break the link while
5561 editing one of the files, so that the two files may
5562 unwittingly become different. The second is that
5563 <prgn>dpkg</prgn> might break the hard link while
5564 upgrading <tt>conffile</tt>s.
5570 The other way to do it is via the maintainer scripts.
5571 In this case, the configuration file must not be listed as
5572 a <tt>conffile</tt> and must not be part of the package
5573 distribution. If the existence of a file is required for
5574 the package to be sensibly configured it is the
5575 responsibility of the package maintainer to write scripts
5576 which correctly create, update, maintain and
5577 remove-on-purge the file. These scripts must be idempotent
5578 (i.e., must work correctly if <prgn>dpkg</prgn> needs to
5579 re-run them due to errors during installation or removal),
5580 must cope with all the variety of ways <prgn>dpkg</prgn>
5581 can call maintainer scripts, must not overwrite or
5582 otherwise mangle the user's configuration without asking,
5583 must not ask unnecessary questions (particularly during
5584 upgrades), and otherwise be good citizens.</p>
5587 The scripts are not required to configure every possible option for
5588 the package, but only those necessary to get the package
5589 running on a given system. Ideally the sysadmin should not
5590 have to do any configuration other than that done
5591 (semi-)automatically by the <tt>postinst</tt> script.</p>
5594 A common practice is to create a script called
5595 <tt><var>package</var>-configure</tt> and have the
5596 package's <tt>postinst</tt> call it if and only if the
5597 configuration file does not already exist. In certain
5598 cases it is useful for there to be an example or template
5599 file which the maintainer scripts use. Such files should
5600 be in <tt>/usr/share/<package></tt> or
5601 <tt>/usr/lib/<package></tt> with a symbolic link
5602 from <tt>/usr/share/doc/<package>/examples</tt>
5603 if they are examples, and should be
5604 perfectly ordinary <prgn>dpkg</prgn>-handled files
5605 (<em>not</em> <tt>conffiles</tt>).
5609 These two styles of configuration file handling must
5610 not be mixed, for that way lies madness:
5611 <prgn>dpkg</prgn> will ask about overwriting the file
5612 every time the package is upgraded.</p>
5617 <heading>Sharing configuration files</heading>
5619 Packages which specify the same file as
5620 `<tt>conffile</tt>' must be tagged as <em>conflicting</em>
5625 The maintainer scripts must not alter the conffile of
5626 <em>any</em> package, including the one the scripts belong
5630 If two or more packages use the same configuration file
5631 and it is reasonable for both to be installed at the same
5632 time, one of these packages must be defined as
5633 <em>owner</em> of the configuration file, i.e., it will be
5634 the package to list that distributes the file and lists it
5635 as a <tt>conffile</tt>. Other packages that use the
5636 configuration file must depend on the owning package if
5637 they require the configuration file to operate. If the
5638 other package will use the configuration file if present,
5639 but is capable of operating without it, no dependency need
5643 If it is desirable for two or more related packages to
5644 share a configuration file <em>and</em> for all of the
5645 related packages to be able to modify that configuration
5646 file, then the following should be done:
5650 have one of the related packages (the "core"
5651 package) manage the configuration file with
5652 maintainer scripts as described in the previous
5656 the core package should also provide a program that
5657 the other packages may use to modify the
5658 configuration file.</p>
5662 the related packages must use the provided program
5663 to make any modifications to the configuration file.
5664 They should either depend on the core package to
5665 guarantee that the configuration modifier program is
5666 available or accept gracefully that they cannot
5667 modify the configuration file if it is not.</p>
5672 Sometimes it's appropriate to create a new package which
5673 provides the basic infrastructure for the other packages
5674 and which manages the shared configuration files. (Check
5675 out the <tt>sgml-base</tt> package as an example.)</p>
5679 <heading>User configuration files ("dotfiles")</heading>
5682 Files in <tt>/etc/skel</tt> will automatically be copied
5683 into new user accounts by <prgn>adduser</prgn>. They
5684 should not be referenced there by any program.</p>
5687 Therefore, if a program needs a dotfile to exist in
5688 advance in <tt>$HOME</tt> to work sensibly, that dotfile
5689 should be installed in <tt>/etc/skel</tt> (and listed in
5690 conffiles, if it is not generated and modified dynamically
5691 by the package's installation scripts).</p>
5694 However, programs that require dotfiles in order to
5695 operate sensibly (dotfiles that they do not create
5696 themselves automatically, that is) are a bad thing, and
5697 programs should be configured by the Debian default
5698 installation as close to normal as possible.</p>
5701 Therefore, if a program in a Debian package needs to be
5702 configured in some way in order to operate sensibly that
5703 configuration should be done in a site-wide global
5704 configuration file elsewhere in <tt>/etc</tt>. Only if the
5705 program doesn't support a site-wide default configuration
5706 and the package maintainer doesn't have time to add it
5707 may a default per-user file be placed in
5708 <tt>/etc/skel</tt>.</p>
5711 <tt>/etc/skel</tt> should be as empty as we can make it.
5712 This is particularly true because there is no easy
5713 mechanism for ensuring that the appropriate dotfiles are
5714 copied into the accounts of existing users when a package
5720 <heading>Log files</heading>
5722 The traditional approach to log files has been to set up ad
5723 hoc log rotation schemes using simple shell scripts and
5724 cron. While this approach is highly customizable, it
5725 requires quite a lot of sysadmin work. Even though the
5726 original Debian system helped a little by automatically
5727 installing a system which can be used as a template, this
5728 was deemed not enough.
5732 A better scheme is to use logrotate, a GPL'd program
5733 developed by Red Hat, which centralizes log management. It
5734 has both a configuration file (<tt>/etc/logrotate.conf</tt>)
5735 and a directory where packages can drop logrotation info
5736 (<tt>/etc/logrotate.d</tt>).
5740 Log files should usually be named
5741 <tt>/var/log/<var>package</var>.log</tt>. If you have many
5742 log files, or need a separate directory for permissions
5743 reasons (<tt>/var/log</tt> is writable only by
5744 <tt>root</tt>), you should usually create a directory named
5745 <tt>/var/log/<var>package</var></tt>.</p>
5748 Log files must be rotated occasionally so
5749 that they don't grow indefinitely; the best way to do this
5750 is to drop a script into the directory
5751 <tt>/etc/logrotate.d</tt> and use the facilities provided by
5752 logrotate. Here is a good example for a logrotate config
5753 file (for more information see <manref name="logrotate"
5761 /etc/init.d/foo force-reload
5765 Which rotates all files under `/var/log/foo', saves 12
5766 compressed generations, and sends a HUP signal at the end of
5772 Log files should be removed when the package is
5773 purged (but not when it is only removed), by checking the
5774 argument to the <tt>postrm</tt> script (see the <em>Debian
5775 Packaging Manual</em> for details).</p>
5780 <heading>Permissions and owners</heading>
5783 The rules in this section are guidelines for general use.
5784 If necessary you may deviate from the details below.
5785 However, if you do so you must make sure that what is done
5786 is secure and you should try to be as consistent as possible
5787 with the rest of the system. You should probably also
5788 discuss it on <prgn>debian-devel</prgn> first.</p>
5791 Files should be owned by <tt>root.root</tt>, and made
5792 writable only by the owner and universally readable (and
5793 executable, if appropriate).</p>
5796 Directories should be mode 755 or (for group-writability)
5797 mode 2775. The ownership of the directory should be
5798 consistent with its mode--if a directory is mode 2775, it
5799 should be owned by the group that needs write access to
5803 Setuid and setgid executables should be mode 4755 or 2755
5804 respectively, and owned by the appropriate user or group.
5805 They should not be made unreadable (modes like 4711 or
5806 2711 or even 4111); doing so achieves no extra security,
5807 because anyone can find the binary in the freely available
5808 Debian package--it is merely inconvenient. For the same
5809 reason you should not restrict read or execute permissions
5810 on non-set-id executables.</p>
5813 Some setuid programs need to be restricted to particular
5814 sets of users, using file permissions. In this case they
5815 should be owned by the uid to which they are set-id, and
5816 by the group which should be allowed to execute them.
5817 They should have mode 4754; there is no point in making
5818 them unreadable to those users who must not be allowed to
5822 You must not arrange that the system administrator can only
5823 reconfigure the package to correspond to their local
5824 security policy by changing the permissions on a binary.
5825 Ordinary files installed by <prgn>dpkg</prgn> (as opposed
5826 to conffiles and other similar objects) have their
5827 permissions reset to the distributed permissions when the
5828 package is reinstalled. Instead you should consider (for
5829 example) creating a group for people allowed to use the
5830 program(s) and making any setuid executables executable
5831 only by that group.</p>
5834 If you need to create a new user or group for your package
5835 there are two possibilities. Firstly, you may need to
5836 make some files in the binary package be owned by this
5837 user or group, or you may need to compile the user or
5838 group id (rather than just the name) into the binary
5839 (though this latter should be avoided if possible, as in
5840 this case you need a statically allocated id).</p>
5843 If you need a statically allocated id, you must ask for a
5844 user or group id from the base system
5845 maintainer, and must not release the package until you
5846 have been allocated one. Once you have been allocated one
5847 you must make the package depend on a version of the base
5848 system with the id present in <tt>/etc/passwd</tt> or
5849 <tt>/etc/group</tt>, or alternatively arrange for your
5850 package to create the user or group itself with the
5851 correct id (using <tt>adduser</tt>) in its pre- or
5852 post-installation script (the latter is to be preferred if
5853 it is possible).</p>
5856 On the other hand, the program might be able to determine the
5857 uid or gid from the group name at runtime, so that a
5858 dynamic id can be used. In this case you should choose an
5859 appropriate user or group name, discussing this on
5860 <prgn>debian-devel</prgn> and checking with the base
5861 system maintainer that it is unique and that they do not
5862 wish you to use a statically allocated id instead. When
5863 this has been checked you must arrange for your package to
5864 create the user or group if necessary using
5865 <prgn>adduser</prgn> in the pre- or post-installation
5866 script (again, the latter is to be preferred if it is
5870 Note that changing the numeric value of an id associated with a name
5871 is very difficult, and involves searching the file system for all
5872 appropriate files. You need to think carefully whether a static or
5873 dynamic id is required, since changing your mind later will cause
5878 <chapt id="customized-programs">
5879 <heading>Customized programs</heading>
5881 <sect id="arch-spec">
5882 <heading>Architecture specification strings</heading>
5885 If a program needs to specify an <em>architecture specification
5886 string</em> in some place, the following format should be used:
5888 <arch>-<os>
5890 where `<arch>' is one of the following: i386, alpha, arm, m68k,
5891 powerpc, sparc and `<os>' is one of: linux, gnu. Use
5892 of <em>gnu</em> in this string is reserved for the GNU/Hurd
5893 operating system.</p>
5895 Note, that we don't want to use `<arch>-debian-linux'
5896 to apply to the rule `architecture-vendor-os' since this
5897 would make our programs incompatible to other Linux
5898 distributions. Also note, that we don't use
5899 `<arch>-unknown-linux', since the `unknown' does not
5900 look very good.</p></sect>
5904 <heading>Daemons</heading>
5907 The configuration files <tt>/etc/services</tt>,
5908 <tt>/etc/protocols</tt>, and <tt>/etc/rpc</tt> are managed
5909 by the <prgn>netbase</prgn> package and may not be modified
5910 by other packages.</p>
5913 If a package requires a new entry in one of these files, the
5914 maintainer should get in contact with the
5915 <prgn>netbase</prgn> maintainer, who will add the entries
5916 and release a new version of the <prgn>netbase</prgn>
5920 The configuration file <tt>/etc/inetd.conf</tt> must not be
5921 modified by the package's scripts except via the
5922 <prgn>update-inetd</prgn> script or the
5923 <prgn>DebianNet.pm</prgn> Perl module.</p>
5926 If a package wants to install an example entry into
5927 <tt>/etc/inetd.conf</tt>, the entry must be preceded with
5928 exactly one hash character (<tt>#</tt>). Such lines are
5929 treated as `commented out by user' by the
5930 <prgn>update-inetd</prgn> script and are not changed or
5931 activated during a package updates.</p></sect>
5935 <heading>Using pseudo-ttys and modifying wtmp, utmp and lastlog</heading>
5938 Some programs need to create pseudo-ttys. This should be done
5939 using Unix98 ptys if the C library supports it. The resulting
5940 program must not be installed setuid root, unless that
5941 is required for other functionality.
5945 The files <tt>/var/run/utmp</tt>, <tt>/var/log/wtmp</tt> and
5946 <tt>/var/log/lastlog</tt> must be installed writeable by
5947 group utmp. Programs who need to modify those files must
5948 be installed setgid utmp.
5953 <heading>Editors and pagers</heading>
5956 Some programs have the ability to launch an editor or pager
5957 program to edit or display a text document. Since there are
5958 lots of different editors and pagers available in the Debian
5959 distribution, the system administrator and each user should
5960 have the possibility to choose his/her preferred editor and
5964 In addition, every program should choose a good default
5965 editor/pager if none is selected by the user or system
5969 Thus, every program that launches an editor or pager must
5970 use the EDITOR or PAGER environment variables to determine
5971 the editor/pager the user wants to get started. If these
5972 variables are not set, the programs <tt>/usr/bin/editor</tt>
5973 and <tt>/usr/bin/pager</tt> should be used, respectively.</p>
5976 These two files are managed through `alternatives.' That is,
5977 every package providing an editor or pager must call the
5978 <prgn>update-alternatives</prgn> script to register these
5982 If it is very hard to adapt a program to make us of the
5983 EDITOR and PAGER variables, that program may be configured
5984 to use <tt>/usr/bin/sensible-editor</tt> and
5985 <tt>/usr/bin/sensible-pager</tt> as editor or pager program,
5986 respectively. These are two scripts provided in the Debian
5987 base system that check the EDITOR and PAGER variables and
5988 launch the appropriate program or fall back to
5989 <tt>/usr/bin/editor</tt> and <tt>/usr/bin/pager</tt>,
5993 A program may also use the VISUAL environment variable to
5994 determine the user's choice of editor. If it exists, it
5995 should take precedence over EDITOR. This is in fact what
5996 <tt>/usr/bin/sensible-editor</tt> does.</p>
5999 It is not required for a package to depend on
6000 `editor' and `pager', nor is it required for a package to
6001 provide such virtual packages.
6004 The Debian base system already provides an editor and
6013 <sect id="web-appl">
6014 <heading>Web servers and applications</heading>
6017 This section describes the locations and URLs that should
6018 be used by all web servers and web application in the Debian
6024 <p>Cgi-bin executable files are installed in the
6027 /usr/lib/cgi-bin/<cgi-bin-name>
6029 and should be referred to as
6031 http://localhost/cgi-bin/<cgi-bin-name>
6032 </example></p></item>
6035 <item><p>Access to html documents</p>
6038 Html documents for a package are stored in
6039 <tt>/usr/share/doc/<var>package</var></tt> but should
6040 be accessed via symlinks as
6041 <tt>/usr/doc/<var>package</var></tt><footnote> for
6042 backward compatibility, see <ref id="usrdoc"></footnote>
6043 and can be referred to as
6045 http://localhost/doc/<package>/<filename>
6046 </example></p></item>
6049 <item><p>Web Document Root</p>
6052 Web Applications should try to avoid storing files in
6053 the Web Document Root. Instead they should use the
6054 /usr/share/doc/<package> directory for documents and
6055 register the Web Application via the menu package. If
6056 access to the web-root is unavoidable then use
6060 as the Document Root. This might be just a
6061 symbolic link to the location where the sysadmin has
6062 put the real document root.</p>
6065 </enumlist></p></sect>
6068 <sect id="mail-transport-agents">
6069 <heading>Mail transport, delivery and user agents</heading>
6072 Debian packages which process electronic mail, whether
6073 mail-user-agents (MUAs) or mail-transport-agents (MTAs),
6074 must make sure that they are compatible with the
6075 configuration decisions below. Failure to do this may
6076 result in lost mail, broken <tt>From:</tt> lines, and other
6077 serious brain damage!</p>
6080 The mail spool is <tt>/var/mail</tt> and the interface
6081 to send a mail message is <tt>/usr/sbin/sendmail</tt> (as
6082 per the FHS). On older systems, the mail spool may be
6083 physically located in /var/spool/mail, but all access to the
6084 mail spool should be via the /var/mail symlink. The mail
6085 spool is part of the base system and not part of the MTA
6090 All Debian MUAs, MTAs, MDAs and other mailbox accessing
6091 programs (like IMAP daemons) must lock the mailbox in an
6092 NFS-safe way. This means that <tt>fcntl()</tt> locking must
6093 be combined with dot locking. To avoid deadlocks, a
6094 program should use <tt>fcntl()</tt> first and dot locking
6095 after this or alternatively implement the two locking
6096 methods in a non blocking way<footnote>
6098 If it is not possible to establish both locks, the
6099 system shouldn't wait for the second lock to be
6100 established, but remove the first lock, wait a (random)
6101 time, and start over locking again.</p>
6102 </footnote>. Using the functions <tt>maillock</tt> and
6103 <tt>mailunlock</tt> provided by the
6104 <tt>liblockfile*</tt><footnote>
6106 <tt>liblockfile</tt> version >>1.01</p>
6107 </footnote> packages is the recommended way to realize this.
6111 Mailboxes are generally 660 <tt><var>user</var>.mail</tt>
6112 unless the user has chosen otherwise. A MUA may remove a
6113 mailbox (unless it has nonstandard permissions) in which
6114 case the MTA or another MUA must recreate it if needed.
6115 Mailboxes must be writable by group mail.</p>
6118 The mail spool is 2775 <tt>root.mail</tt>, and MUAs should
6119 be setgid mail to do the locking mentioned above (and
6120 must obviously avoid accessing other users' mailboxes
6121 using this privilege).</p>
6124 <tt>/etc/aliases</tt> is the source file for the system mail
6125 aliases (e.g., postmaster, usenet, etc.)--it is the one
6126 which the sysadmin and <tt>postinst</tt> scripts may edit.
6127 After <tt>/etc/aliases</tt> is edited the program or human
6128 editing it must call <prgn>newaliases</prgn>. All MTA
6129 packages must come with a <prgn>newaliases</prgn> program,
6130 even if it does nothing, but older MTA packages do not do
6131 this so programs should not fail if <prgn>newaliases</prgn>
6132 cannot be found.</p>
6135 The convention of writing <tt>forward to
6136 <var>address</var></tt> in the mailbox itself is not
6137 supported. Use a <tt>.forward</tt> file instead.</p>
6140 The <prgn>rmail</prgn> program used by UUCP
6141 for incoming mail should be <tt>/usr/sbin/rmail</tt>.
6142 Likewise, <prgn>rsmtp</prgn>, for receiving
6143 batch-SMTP-over-UUCP, should be <tt>/usr/sbin/rsmtp</tt> if it
6147 If you need to know what name to use (for example) on
6148 outgoing news and mail messages which are generated locally,
6149 you should use the file <tt>/etc/mailname</tt>. It will
6150 contain the portion after the username and <tt>@</tt> (at)
6151 sign for email addresses of users on the machine (followed
6155 A package should check for the existence of this file. If
6156 it exists it should use it without comment. (An MTA's
6157 prompting configuration script may wish to prompt the user
6158 even if it finds this file exists.) If it does not exist it
6159 should prompt the user for the value and store it in
6160 <tt>/etc/mailname</tt> as well as using it in the package's
6161 configuration. The prompt should make it clear that the
6162 name will not just be used by that package. For example, in
6163 this situation the INN package says:
6165 Please enter the `mail name' of your system. This is the
6166 hostname portion of the address to be shown on outgoing
6167 news and mail messages. The default is
6168 <var>syshostname</var>, your system's host name. Mail
6169 name [`<var>syshostname</var>']:
6171 where <var>syshostname</var> is the output of <tt>hostname
6172 --fqdn</tt>.</p></sect>
6176 <heading>News system configuration</heading>
6179 All the configuration files related to the NNTP (news)
6180 servers and clients should be located under
6181 <tt>/etc/news</tt>.</p>
6184 There are some configuration issues that apply to a number
6185 of news clients and server packages on the machine. These
6189 <tag>/etc/news/organization</tag>
6190 <item><p>A string which should appear as the
6191 organization header for all messages posted
6192 by NNTP clients on the machine</p></item>
6194 <tag>/etc/news/server</tag>
6195 <item><p>Contains the FQDN of the upstream NNTP
6196 server, or localhost if the local machine is
6197 an NNTP server.</p></item>
6200 Other global files may be added as required for cross-package news
6201 configuration.</p></sect>
6205 <heading>Programs for the X Window System</heading>
6208 <em>Programs that may be configured with support for the X Window
6209 System</em> must be configured to do so and must declare any
6210 package dependencies necessary to satisfy their runtime
6211 requirements when using the X Window System, unless the package
6212 in question is of standard or higher priority, in which case
6213 X-specific binaries may be split into a separate package, or
6214 alternative versions of the package with X support may be
6220 <em>Packages which provide an X server</em> that, directly or
6221 indirectly, communicates with real input and display hardware
6222 should declare in their control data that they provide the
6223 virtual package <tt>xserver</tt>.
6226 This implements current practice, and provides an actual
6227 policy for usage of the "xserver" virtual package which
6228 appears in the virtual packages list. In a nutshell, X
6229 servers that interface directly with the display and input
6230 hardware or via another subsystem (e.g., GGI) should provide
6231 xserver. Things like Xvfb, Xnest, and Xprt should not.
6237 <em>Packages that provide a terminal emulator</em> for the X
6238 Window System which support a terminal type with a terminfo
6239 description provided in the <tt>ncurses-base</tt> package
6240 should declare in their control data that they provide the
6241 virtual package <tt>x-terminal-emulator</tt>. They should
6242 also register themselves as an alternative for
6243 <tt>/usr/bin/x-terminal-emulator</tt>, with a priority of
6248 <em>Packages that provide window managers</em> should declare in
6249 their control data that they provide the virtual package
6250 <tt>x-window-manager</tt>. They should also register themselves as an
6251 alternative for <tt>/usr/bin/x-window-manager</tt>, with a priority
6252 calculated as follows:
6254 <item>Start with a priority of 20.</item>
6255 <item>If the window manager supports the Debian menu system,
6256 add 20 points if this support is available in the
6257 package's default configuration (i.e., no
6258 configuration files belonging to the system or user
6259 have to be edited to activate the feature); if
6260 configuration files must be modified, add only 10
6262 <item>If the window manager permits the X session to be
6263 restarted using a <em>different</em> window manager
6264 (without killing the X server) in its default
6265 configuration, add 10 points; otherwise add
6271 <em>Packages that provide fonts for the X Window System</em>
6272 must do a number of things to ensure that they are both
6273 available without modification of the X or font server
6274 configuration, and that they do not corrupt files used by
6275 other font packages to register information about themselves.
6278 Fonts of any type supported by the X Window System
6279 should be be in a separate binary package from any
6280 executables, libraries, or documentation (except that
6281 specific to the fonts shipped); if a program or
6282 library is <em>unusable</em> without one or more
6283 specific fonts, the package containing the program or
6284 library should declare a dependency on the package(s)
6285 containing the font(s) it requires.
6288 BDF fonts should be converted to PCF fonts with the
6289 <tt>bdftopcf</tt> utility (available in the
6290 <tt>xutils</tt> package, <tt>gzip</tt>ped, and
6291 placed in a directory that corresponds to their
6295 100 dpi fonts should be placed in
6296 <tt>/usr/X11R6/lib/X11/fonts/100dpi/</tt>.
6299 75 dpi fonts should be placed in
6300 <tt>/usr/X11R6/lib/X11/fonts/75dpi/</tt>.
6303 Character-cell fonts, cursor fonts, and other
6304 low-resolution fonts should be placed in
6305 <tt>/usr/X11R6/lib/X11/fonts/misc/</tt>.
6310 Speedo fonts should be placed in
6311 <tt>/usr/X11R6/lib/X11/fonts/Speedo/</tt>.
6314 Type 1 fonts should be placed in
6315 <tt>/usr/X11R6/lib/X11/fonts/Type1/</tt>. If font
6316 metric files are available, they may be placed here as
6320 Subdirectories of <tt>/usr/X11R6/lib/X11/fonts/</tt>
6321 other than those listed above should be neither created nor
6322 used. (The <tt>PEX</tt> and <tt>cyrillic</tt> directories are
6323 excepted for historical reasons, but installation of files into
6324 these directories remains discouraged.)
6327 Font packages may, instead of placing files directly in
6328 the X font directories listed above, provide symbolic links in
6329 the font directory which point to the files' actual location
6330 in the filesystem. Such a location should comply with the
6334 Font packages should not contain both 75dpi and 100dpi
6335 versions of a font. If both are available, they should be
6336 provided in separate binary packages with "-75dpi" or "-100dpi"
6337 appended to the names of the packages containing the
6338 corresponding fonts.
6341 Fonts destined for the <tt>misc</tt> subdirectory should
6342 not be included in the same package as 75dpi or 100dpi fonts;
6343 instead, they should be provided in a separate package with
6344 "-misc" appended to its name.
6347 Font packages <em>must not</em> provide the files
6348 <tt>fonts.dir</tt>, <tt>fonts.alias</tt>, or
6349 <tt>fonts.scale</tt> in a font directory.
6352 <tt>fonts.dir</tt> files must not be provided at
6356 <tt>fonts.alias</tt> and <tt>fonts.scale</tt>
6357 files, if needed, should be provided in the
6359 <tt>/etc/X11/fonts/<em>fontdir</em>/<em>package</em>.<em>extension</em></tt>,
6360 where <em>fontdir</em> is the name of the
6362 <tt>/usr/X11R6/lib/X11/fonts/</tt> where the
6363 package's corresponding fonts are stored (e.g.,
6364 <tt>75dpi</tt> or <tt>misc</tt>),
6365 <em>package</em> is the name of the package that
6366 provides these fonts, and <em>extension</em> is
6367 either <tt>scale</tt> or <tt>alias</tt>,
6368 whichever corresponds to the file
6374 Font packages must declare a dependency on
6375 <tt>xutils</tt> and, in the package
6376 post-installation and post-removal scripts, invoke the
6377 <tt>mkfontdir</tt> command on each directory into
6378 which they installed fonts.
6381 Font packages that provide one or more
6382 <tt>fonts.scale</tt> files as described above must declare a
6383 versioned dependency on <tt>xutils (>=
6384 4.0.2)</tt> and invoke <tt>update-fonts-scale</tt> on each
6385 directory into which they installed fonts
6386 <em>before</em> invoking <tt>mkfontdir</tt> on that
6387 directory. This invocation must occur in both the
6388 post-installation and post-removal scripts.
6391 Font packages that provide one or more
6392 <tt>fonts.alias</tt> files as described above must
6393 declare a versioned dependency on <tt>xutils
6394 (>= 4.0.2)</tt> and, in the package
6395 post-installation and post-removal scripts, invoke
6396 <tt>update-fonts-alias</tt> on each directory into
6397 which they installed fonts.
6400 Font packages must not provide alias names for the
6401 fonts they include which collide with alias names already in
6402 use by fonts already packaged.
6405 Font packages must not provide fonts with the same XLFD
6406 registry name as another font already packaged.
6412 <em>Application defaults</em> files must be installed in the
6413 directory <tt>/etc/X11/app-defaults/</tt> (use of a
6414 localized subdirectory of <tt>/etc/X11/</tt> as described in
6415 the <em>X Toolkit Intrinsics - C Language Interface</em>
6416 manual is also permitted). They must be registered as
6417 <em>conffile</em>s or handled as configuration files. For
6418 programs that are not linked against the X Toolkit (Xt)
6419 library, customization of programs' X resources may also be
6420 supported with the provision of a file with the same name as
6421 that of the package placed in the
6422 <tt>/etc/X11/Xresources/</tt> directory, which must
6423 registered as a <em>conffile</em> or handled as a
6424 configuration file. <em>Important:</em> packages that
6425 install files into the <tt>/etc/X11/Xresources/</tt>
6426 directory <em>must</em> declare a conflict with <tt>xbase
6427 (<< 3.3.2.3a-2)</tt>; if this is not done it is
6428 possible for the installing package to destroy a
6429 previously-existing <tt>/etc/X11/Xresources</tt> file which
6430 had been customized by the system administrator.
6434 <em>Packages using the X Window System should abide by the FHS
6435 standard whenever possible</em>; they should install binaries,
6436 libraries, manual pages, and other files in FHS-mandated
6437 locations wherever possible. This means that files must
6438 not be installed into <tt>/usr/X11R6/bin/</tt>,
6439 <tt>/usr/X11R6/lib/</tt>, or <tt>/usr/X11R6/man/</tt> unless
6440 this is necessary for the package to operate properly.
6441 Configuration files for window managers and display managers
6442 should be placed in a subdirectory of <tt>/etc/X11/</tt>
6443 corresponding to the package name due to these programs'
6444 tight integration with the mechanisms of the X Window
6445 System. Application-level programs should use the
6446 <tt>/etc/</tt> directory unless otherwise mandated by
6447 policy. The installation of files into subdirectories of
6448 <tt>/usr/X11R6/include/X11/</tt> and
6449 <tt>/usr/X11R6/lib/X11/</tt> is permitted but discouraged;
6450 package maintainers should determine if subdirectories of
6451 <tt>/usr/lib/</tt> and <tt>/usr/share/</tt> can be used
6452 instead (symlinks from the X11R6 directories to
6453 FHS-compliant locations is encouraged if the program is not
6454 easily configured to look elsewhere for its files).
6455 Packages must not provide -- or install files into -- the
6456 directories <tt>/usr/bin/X11/</tt>,
6457 <tt>/usr/include/X11/</tt>, or <tt>/usr/lib/X11/</tt>.
6458 Files within a package should, however, make reference to
6459 these directories, rather than their X11R6-named
6460 counterparts <tt>/usr/X11R6/bin/</tt>,
6461 <tt>/usr/X11R6/include/X11/</tt>, and
6462 <tt>/usr/X11R6/lib/X11/</tt>, if the resources being
6463 referred to have not been moved to FHS-compliant locations.
6467 <em>Programs that require the non-DFSG-compliant OSF/Motif
6468 library</em> should be compiled against and tested with
6469 LessTif (a free re-implementation of Motif) instead. If the
6470 maintainer judges that the program or programs do not work
6471 sufficiently well with LessTif to be distributed and
6472 supported, but do so when compiled against Motif, then two
6473 versions of the package should be created; one linked
6474 statically against Motif and with <tt>-smotif</tt> appended
6475 to the package name, and one linked dynamically against
6476 Motif and with <tt>-dmotif</tt> appended to the package
6477 name. Both Motif-linked versions are dependent upon
6478 non-DFSG-compliant software and thus cannot be uploaded to
6479 the main distribution; if the software is itself
6480 DFSG-compliant it may be uploaded to the contrib
6481 distribution. While known existing versions of OSF/Motif
6482 permit unlimited redistribution of binaries linked against
6483 the library (whether statically or dynamically), it is the
6484 package maintainer's responsibility to determine whether
6485 this is permitted by the license of the copy of OSF/Motif in
6486 his or her possession.
6491 <heading>Perl programs and modules</heading>
6493 Perl programs and modules should follow the current Perl
6494 policy as defined in the file found on
6495 <ftpsite>ftp.debian.org</ftpsite> in
6496 <ftppath>/debian/doc/package-developer/perl-policy.txt.gz</ftppath>
6497 or your local mirror. In addition, it is included in the
6498 <tt>debian-policy</tt> package.
6503 <heading>Emacs lisp programs</heading>
6506 Please refer to the `Debian Emacs Policy' (documented in
6507 <tt>debian-emacs-policy.gz</tt> of the
6508 <prgn>emacsen-common</prgn> package) for details of how to
6509 package emacs lisp programs.</p></sect>
6513 <heading>Games</heading>
6516 The permissions on /var/games are 755
6517 <tt>root.root</tt>.</p>
6520 Each game decides on its own security policy.</p>
6523 Games which require protected, privileged access to
6524 high-score files, savegames, etc., may be made
6525 set-<em>group</em>-id (mode 2755) and owned by
6526 <tt>root.games</tt>, and use files and directories with
6527 appropriate permissions (770 <tt>root.games</tt>, for
6528 example). They must not be made
6529 set-<em>user</em>-id, as this causes security problems. (If
6530 an attacker can subvert any set-user-id game they can
6531 overwrite the executable of any other, causing other players
6532 of these games to run a Trojan horse program. With a
6533 set-group-id game the attacker only gets access to less
6534 important game data, and if they can get at the other
6535 players' accounts at all it will take considerably more
6539 Some packages, for example some fortune cookie programs, are
6540 configured by the upstream authors to install with their
6541 data files or other static information made unreadable so
6542 that they can only be accessed through set-id programs
6543 provided. You should not do this in a Debian package: anyone can
6544 download the <tt>.deb</tt> file and read the data from it,
6545 so there is no point making the files unreadable. Not
6546 making the files unreadable also means that you don't have
6547 to make so many programs set-id, which reduces the risk of a
6551 As described in the FHS, binaries of games should be
6552 installed in the directory <tt>/usr/games</tt>. This also
6553 applies to games that use the X Window System. Manual pages
6554 for games (X and non-X games) should be installed in
6555 <tt>/usr/share/man/man6</tt>.</p>
6559 <chapt><heading>Documentation</heading>
6563 <heading>Manual pages</heading>
6566 You should install manual pages in <prgn>nroff</prgn> source
6567 form, in appropriate places under <tt>/usr/share/man</tt>. You
6568 should only use sections 1 to 9 (see the FHS for more
6569 details). You must not install a preformatted `cat
6573 Each program, utility, and function should have an
6574 associated manpage included in the same package. It is
6575 suggested that all configuration files also have a manual
6576 page included as well.
6580 If no manual page is available for a particular program,
6581 utility, function or configuration file and this is reported as a bug on
6582 debian-bugs, a symbolic link from the requested manual page
6583 to the <manref name="undocumented" section="7"> manual page
6584 may be provided. This symbolic link can be created from
6585 <tt>debian/rules</tt> like this:
6587 ln -s ../man7/undocumented.7.gz \
6588 debian/tmp/usr/share/man/man[1-9]/the_requested_manpage.[1-9].gz
6590 This manpage claims that the lack of a manpage has been
6591 reported as a bug, so you may only do this if it really has
6592 (you can report it yourself, if you like). Do not close the
6593 bug report until a proper manpage is available.</p>
6596 You may forward a complaint about a missing manpage to the
6597 upstream authors, and mark the bug as forwarded in the
6598 Debian bug tracking system. Even though the GNU Project do
6599 not in general consider the lack of a manpage to be a bug,
6600 we do--if they tell you that they don't consider it a bug
6601 you should leave the bug in our bug tracking system open
6605 Manual pages should be installed compressed using <tt>gzip
6609 If one manpage needs to be accessible via several names it
6610 is better to use a symbolic link than the <tt>.so</tt>
6611 feature, but there is no need to fiddle with the relevant
6612 parts of the upstream source to change from <tt>.so</tt> to
6613 symlinks--don't do it unless it's easy. You should not create hard
6614 links in the manual page directories, nor put
6615 absolute filenames in <tt>.so</tt> directives. The filename
6616 in a <tt>.so</tt> in a manpage should be relative to the
6617 base of the manpage tree (usually
6618 <tt>/usr/share/man</tt>).</p></sect>
6622 <heading>Info documents</heading>
6625 Info documents should be installed in <tt>/usr/share/info</tt>.
6626 They should be compressed with <tt>gzip -9</tt>.</p>
6629 Your package should call <prgn>install-info</prgn> to update the Info
6631 file, in its post-installation script:
6633 install-info --quiet --section Development Development \
6634 /usr/share/info/foobar.info
6638 It is a good idea to specify a section for the location of
6639 your program; this is done with the <tt>--section</tt>
6640 switch. To determine which section to use, you should look
6641 at <tt>/usr/share/info/dir</tt> on your system and choose the most
6642 relevant (or create a new section if none of the current
6643 sections are relevant). Note that the <tt>--section</tt>
6644 flag takes two arguments; the first is a regular expression
6645 to match (case-insensitively) against an existing section,
6646 the second is used when creating a new one.</p>
6649 You should remove the entries in the pre-removal script:
6651 install-info --quiet --remove /usr/share/info/foobar.info
6655 If <prgn>install-info</prgn> cannot find a description entry
6656 in the Info file you must supply one. See <manref
6657 name="install-info" section="8"> for details.</p>
6661 <heading>Additional documentation</heading>
6664 Any additional documentation that comes with the package may
6665 be installed at the discretion of the package maintainer.
6666 Text documentation should be installed in a directory
6667 <tt>/usr/share/doc/<var>package</var></tt>, where
6668 <var>package</var> is the name of the package, and
6669 compressed with <tt>gzip -9</tt> unless it is small.</p>
6672 If a package comes with large amounts of documentation which
6673 many users of the package will not require you should create
6674 a separate binary package to contain it, so that it does not
6675 take up disk space on the machines of users who do not need
6676 or want it installed.</p>
6679 It is often a good idea to put text information files
6680 (<tt>README</tt>s, changelogs, and so forth) that come with
6681 the source package in <tt>/usr/share/doc/<var>package</var></tt>
6682 in the binary package. However, you don't need to install
6683 the instructions for building and installing the package, of
6687 Files in <tt>/usr/share/doc</tt> should not be referenced by
6688 any program, and the system administrator should be able to
6689 delete them without causing any programs to break. Any files
6690 that are referenced by programs but are also useful as
6691 standalone documentation should be installed under
6692 <tt>/usr/share/<package>/</tt> and symlinked in
6693 <tt>/usr/share/doc/<package>/</tt>.
6699 <heading>Accessing the documentation</heading>
6702 Former Debian releases placed all additional documentation
6703 in <tt>/usr/doc/<var>package</var></tt>. To realize a
6705 <tt>/usr/share/doc/<var>package</var></tt>, each package
6706 must maintain a symlink <tt>/usr/doc/<var>package</var></tt>
6707 that points to the new location of its documentation in
6708 <tt>/usr/share/doc/<var>package</var></tt><footnote>These
6709 symlinks will be removed in the future, but they have to be
6710 there for compatibility reasons until all packages have
6711 moved and the policy is changed accordingly.</footnote>.
6712 The symlink must be created when the package is installed;
6713 it cannot be contained in the package itself due to problems
6714 with <prgn>dpkg</prgn>. One reasonable way to accomplish
6715 this is to put the following in the package's
6716 <prgn>postinst</prgn>:
6718 if [ "$1" = "configure" ]; then
6719 if [ -d /usr/doc -a ! -e /usr/doc/#PACKAGE# \
6720 -a -d /usr/share/doc/#PACKAGE# ]; then
6721 ln -sf ../share/doc/#PACKAGE# /usr/doc/#PACKAGE#
6725 And the following in the package's <prgn>prerm</prgn>:
6727 if [ \( "$1" = "upgrade" -o "$1" = "remove" \) \
6728 -a -L /usr/doc/#PACKAGE# ]; then
6729 rm -f /usr/doc/#PACKAGE#
6736 <heading>Preferred documentation formats</heading>
6739 The unification of Debian documentation is being carried out
6743 If your package comes with extensive documentation in a
6744 mark up format that can be converted to various other formats
6745 you should if possible ship HTML versions in a binary
6746 package, in the directory
6747 <tt>/usr/share/doc/<var>appropriate package</var></tt> or its
6750 <p>The rationale: The important thing here is that HTML
6751 docs should be available in <em>some</em> package, not
6752 necessarily in the main binary package, though. </p>
6757 Other formats such as PostScript may be provided at your
6761 <sect id="copyrightfile">
6762 <heading>Copyright information</heading>
6765 Every package must be accompanied by a verbatim copy of its
6766 copyright and distribution license in the file
6767 /usr/share/doc/<package-name>/copyright. This file must
6768 neither be compressed nor be a symbolic link.</p>
6771 In addition, the copyright file must say where the upstream
6772 sources (if any) were obtained, and should explain briefly what
6773 modifications were made in the Debian version of the package
6774 compared to the upstream one. It should name the original
6775 authors of the package and the Debian maintainer(s) who were
6776 involved with its creation.</p>
6779 A copy of the file which will be installed in
6780 <tt>/usr/share/doc/<var>package</var>/copyright</tt> should be
6781 in <tt>debian/copyright</tt>.</p>
6785 /usr/share/doc/<package-name> may be a symbolic link to a
6786 directory in /usr/share/doc only if two packages both come from
6787 the same source and the first package has a "Depends"
6788 relationship on the second. These rules are important
6789 because copyrights must be extractable by mechanical
6793 Packages distributed under the UCB BSD license, the Artistic
6794 license, the GNU GPL, and the GNU LGPL should refer to the
6795 files /usr/share/common-licenses/BSD,
6796 /usr/share/common-licenses/Artistic,
6797 /usr/share/common-licenses/GPL, and
6798 /usr/share/common-licenses/LGPL.
6801 Why "licenses" and not "copyright"? Because
6802 <tt>/usr/doc/copyright</tt> used to contain all the
6803 copyright files, plus the four common licenses GPL,
6804 LGPL, Artistic and BSD. Now individual copyright files
6805 for packages are no longer in a common directory. Once
6806 <tt>/usr/doc/copyright</tt> is almost empty it makes
6807 sense to rename "copyright" to "licenses"
6810 Why "common-licenses" and not "licenses"? Because if I
6811 put just "licenses" I'm sure I will receive a bug report
6812 saying "license foo is not included in the licenses
6813 directory. They are not all the licenses, just a few
6814 common ones. I could use /usr/share/doc/common-licenses
6815 but I think this is too long, and, after all, the GPL
6816 does not "document" anything, it is merely a license.
6822 You should not use the copyright file as a general <tt>README</tt>
6823 file. If your package has such a file it should be
6824 installed in <tt>/usr/share/doc/<var>package</var>/README</tt> or
6825 <tt>README.Debian</tt> or some other appropriate place.</p>
6829 <heading>Examples</heading>
6832 Any examples (configurations, source files, whatever),
6833 should be installed in a directory
6834 <tt>/usr/share/doc/<var>package</var>/examples</tt>. These
6835 files should not be referenced by any program--they're there
6836 for the benefit of the system administrator and users, as
6837 documentation only. Architecture-specific example files
6838 should be installed in a directory
6839 <tt>/usr/lib/<var>package</var>/examples</tt>, and files in
6840 <tt>/usr/share/doc/<var>package</var>/examples</tt> symlink
6841 to files in it. Or the latter directory may be a symlink to
6845 <sect id="instchangelog">
6846 <heading>Changelog files</heading>
6849 Packages that are not Debian-native must contain a copy of
6850 <tt>debian/changelog</tt> file from the Debian source tree
6851 in <tt>/usr/share/doc/<var>package</var></tt> as
6852 <tt>changelog.Debian.gz</tt>. If an upstream changelog is
6853 available, it should be accessible as
6854 <tt>/usr/share/doc/<var>package</var>/changelog.gz</tt> in
6855 plain text. If the upstream changelog is distributed in
6856 HTML, it should be made available in that form as
6857 <tt>/usr/share/doc/<var>package</var>/changelog.html.gz</tt>
6858 and the <tt>changelog.gz</tt> should be generated using, eg,
6859 <tt>lynx -dump -nolist</tt>. If the upstream changelog files
6860 do not already conform to this naming convention, then this
6861 may be achieved either by renaming the files, or adding a
6862 symbolic link, at the maintainer's discretion.
6865 Rationale: People should not have to look into two
6866 places for upstream changelogs merely because they are
6874 All these files should be installed compressed using <tt>gzip -9</tt>,
6875 as they will become large with time even if they start out
6880 If the package has only one changelog which is used both as
6881 the Debian changelog and the upstream one because there is
6882 no separate upstream maintainer then that changelog should
6883 usually be installed as
6884 <tt>/usr/share/doc/<var>package</var>/changelog.gz</tt>; if
6885 there is a separate upstream maintainer, but no upstream
6886 changelog, then the Debian changelog should still be called
6887 <tt>changelog.Debian.gz</tt>.</p>