<em>ruby</em>, <em>science</em>, <em>shells</em>, <em>sound</em>,
<em>tex</em>, <em>text</em>, <em>utils</em>, <em>vcs</em>,
<em>video</em>, <em>web</em>, <em>x11</em>, <em>xfce</em>,
- <em>zope</em>.
+ <em>zope</em>. The additional section <em>debian-installer</em>
+ contains special packages used by the installer and is not used
+ for normal Debian packages.
+ </p>
+
+ <p>
+ For more information about the sections and their definitions,
+ see the <url id="http://packages.debian.org/unstable/"
+ name="list of sections in unstable">.
</p>
</sect>
<heading>Controlling terminal for maintainer scripts</heading>
<p>
- The maintainer scripts are guaranteed to run with a
- controlling terminal and can interact with the user.
- Because these scripts may be executed with standard output
- redirected into a pipe for logging purposes, Perl scripts
- should set unbuffered output by setting <tt>$|=1</tt> so
- that the output is printed immediately rather than being
- buffered.
+ Maintainer scripts are not guaranteed to run with a controlling
+ terminal and may not be able to interact with the user. They
+ must be able to fall back to noninteractive behavior if no
+ controlling terminal is available. Maintainer scripts that
+ prompt via a program conforming to the Debian Configuration
+ Management Specification (see <ref id="maintscriptprompt">) may
+ assume that program will handle falling back to noninteractive
+ behavior.
</p>
</sect>
+
<sect id="exitstatus">
<heading>Exit status</heading>
</p>
</sect1>
- <sect1>
+ <sect1 id="writing-init">
<heading>Writing the scripts</heading>
<p>
option.
</p>
+ <p>
+ Be careful of using <tt>set -e</tt> in <file>init.d</file>
+ scripts. Writing correct <file>init.d</file> scripts requires
+ accepting various error exit statuses when daemons are already
+ running or already stopped without aborting
+ the <file>init.d</file> script, and common <file>init.d</file>
+ function libraries are not safe to call with <tt>set -e</tt>
+ in effect<footnote>
+ <tt>/lib/lsb/init-functions</tt>, which assists in writing
+ LSB-compliant init scripts, may fail if <tt>set -e</tt> is
+ in effect and echoing status messages to the console fails,
+ for example.
+ </footnote>. For <tt>init.d</tt> scripts, it's often easier
+ to not use <tt>set -e</tt> and instead check the result of
+ each command separately.
+ </p>
+
<p>
If a service reloads its configuration automatically (as
in the case of <prgn>cron</prgn>, for example), the
language currently used to implement it.
</p>
<p>
- Shell scripts (<prgn>sh</prgn> and <prgn>bash</prgn>)
- should almost certainly start with <tt>set -e</tt> so that
- errors are detected. Every script should use
- <tt>set -e</tt> or check the exit status of <em>every</em>
- command.
+ Shell scripts (<prgn>sh</prgn> and <prgn>bash</prgn>) other than
+ <file>init.d</file> scripts should almost certainly start
+ with <tt>set -e</tt> so that errors are detected.
+ <file>init.d</file> scripts are something of a special case, due
+ to how frequently they need to call commands that are allowed to
+ fail, and it may instead be easier to check the exit status of
+ commands directly. See <ref id="writing-init"> for more
+ information about writing <file>init.d</file> scripts.
+ </p>
+ <p>
+ Every script should use <tt>set -e</tt> or check the exit status
+ of <em>every</em> command.
</p>
-
<p>
Scripts may assume that <file>/bin/sh</file> implements the
SUSv3 Shell Command Language<footnote>
security policy by changing the permissions on a binary:
they can do this by using <prgn>dpkg-statoverride</prgn>, as
described below.<footnote>
- Ordinary files installed by <prgn>dpkg</prgn> (as
- opposed to <tt>conffile</tt>s and other similar objects)
- normally have their permissions reset to the distributed
- permissions when the package is reinstalled. However,
- the use of <prgn>dpkg-statoverride</prgn> overrides this
- default behavior. If you use this method, you should
- remember to describe <prgn>dpkg-statoverride</prgn> in
- the package documentation; being a relatively new
- addition to Debian, it is probably not yet well-known.
+ Ordinary files installed by <prgn>dpkg</prgn> (as
+ opposed to <tt>conffile</tt>s and other similar objects)
+ normally have their permissions reset to the distributed
+ permissions when the package is reinstalled. However,
+ the use of <prgn>dpkg-statoverride</prgn> overrides this
+ default behavior.
</footnote>
Another method you should consider is to create a group for
people allowed to use the program(s) and make any setuid
</p>
<p>
- The maintainer scripts are guaranteed to run with a
- controlling terminal and can interact with the user.
- See <ref id="controllingterminal">.
+ The maintainer scripts are not guaranteed to run with a
+ controlling terminal and may not be able to interact with
+ the user. See <ref id="controllingterminal">.
</p>
</item>
</p>
</sect1>
-
- <sect1 id="pkg-dpkgchangelog">
- <heading><file>debian/changelog</file></heading>
-
- <p>
- See <ref id="dpkgchangelog">.
- </p>
-
- <sect2><heading>Defining alternative changelog formats
- </heading>
-
- <p>
- It is possible to use a different format to the standard
- one, by providing a parser for the format you wish to
- use.
- </p>
-
- <p>
- In order to have <tt>dpkg-parsechangelog</tt> run your
- parser, you must include a line within the last 40 lines
- of your file matching the Perl regular expression:
- <tt>\schangelog-format:\s+([0-9a-z]+)\W</tt> The part in
- parentheses should be the name of the format. For
- example, you might say:
- <example>
- @@@ changelog-format: joebloggs @@@
- </example>
- Changelog format names are non-empty strings of alphanumerics.
- </p>
-
- <p>
- If such a line exists then <tt>dpkg-parsechangelog</tt>
- will look for the parser as
- <file>/usr/lib/dpkg/parsechangelog/<var>format-name</var></file>
- or
- <file>/usr/local/lib/dpkg/parsechangelog/<var>format-name</var></file>;
- it is an error for it not to find it, or for it not to
- be an executable program. The default changelog format
- is <tt>dpkg</tt>, and a parser for it is provided with
- the <tt>dpkg</tt> package.
- </p>
-
- <p>
- The parser will be invoked with the changelog open on
- standard input at the start of the file. It should read
- the file (it may seek if it wishes) to determine the
- information required and return the parsed information
- to standard output in the form of a series of control
- fields in the standard format. By default it should
- return information about only the most recent version in
- the changelog; it should accept a
- <tt>-v<var>version</var></tt> option to return changes
- information from all versions present <em>strictly
- after</em> <var>version</var>, and it should then be an
- error for <var>version</var> not to be present in the
- changelog.
- </p>
-
- <p>
- The fields are:
- <list compact="compact">
- <item><qref id="f-Source"><tt>Source</tt></qref></item>
- <item><qref id="f-Version"><tt>Version</tt></qref> (mandatory)</item>
- <item><qref id="f-Distribution"><tt>Distribution</tt></qref> (mandatory)</item>
- <item><qref id="f-Urgency"><tt>Urgency</tt></qref> (mandatory)</item>
- <item><qref id="f-Maintainer"><tt>Maintainer</tt></qref> (mandatory)</item>
- <item><qref id="f-Date"><tt>Date</tt></qref></item>
- <item><qref id="f-Changes"><tt>Changes</tt></qref> (mandatory)</item>
- </list>
- </p>
-
- <p>
- If several versions are being returned (due to the use
- of <tt>-v</tt>), the urgency value should be of the
- highest urgency code listed at the start of any of the
- versions requested followed by the concatenated
- (space-separated) comments from all the versions
- requested; the maintainer, version, distribution and
- date should always be from the most recent version.
- </p>
-
- <p>
- For the format of the <tt>Changes</tt> field see
- <ref id="f-Changes">.
- </p>
-
- <p>
- If the changelog format which is being parsed always or
- almost always leaves a blank line between individual
- change notes these blank lines should be stripped out,
- so as to make the resulting output compact.
- </p>
-
- <p>
- If the changelog format does not contain date or package
- name information this information should be omitted from
- the output. The parser should not attempt to synthesize
- it or find it from other sources.
- </p>
-
- <p>
- If the changelog does not have the expected format the
- parser should exit with a nonzero exit status, rather
- than trying to muddle through and possibly generating
- incorrect output.
- </p>
-
- <p>
- A changelog parser may not interact with the user at
- all.
- </p>
- </sect2>
- </sect1>
-
<sect1 id="pkg-srcsubstvars">
<heading><file>debian/substvars</file> and variable substitutions</heading>
projects / debian / debian-policy.git / commitdiff