</p>
</sect>
- <sect>
+ <sect id="cron-jobs">
<heading>Cron jobs</heading>
<p>
Packages must not modify the configuration file
<file>/etc/crontab</file>, and they must not modify the files in
- <file>/var/spool/cron/crontabs</file>.</p>
+ <file>/var/spool/cron/crontabs</file>.
+ </p>
<p>
- If a package wants to install a job that has to be executed
- via cron, it should place a file with the name of the
- package in one or more of the following directories:
+ If a package wants to install a job that has to be executed via
+ cron, it should place a file named as specified
+ in <ref id="cron-files"> into one or more of the following
+ directories:
<example compact="compact">
/etc/cron.hourly
/etc/cron.daily
As these directory names imply, the files within them are
executed on an hourly, daily, weekly, or monthly basis,
respectively. The exact times are listed in
- <file>/etc/crontab</file>.</p>
+ <file>/etc/crontab</file>.
+ </p>
<p>
All files installed in any of these directories must be
<p>
If a certain job has to be executed at some other frequency or
- at a specific time, the package should install a file
- <file>/etc/cron.d/<var>package</var></file>. This file uses the
- same syntax as <file>/etc/crontab</file> and is processed by
- <prgn>cron</prgn> automatically. The file must also be
+ at a specific time, the package should install a file in
+ <file>/etc/cron.d</file> with a name as specified
+ in <ref id="cron-files">. This file uses the same syntax
+ as <file>/etc/crontab</file> and is processed
+ by <prgn>cron</prgn> automatically. The file must also be
treated as a configuration file. (Note that entries in the
<file>/etc/cron.d</file> directory are not handled by
<prgn>anacron</prgn>. Thus, you should only use this
directory for jobs which may be skipped if the system is not
- running.)</p>
+ running.)
+ </p>
+
<p>
Unlike <file>crontab</file> files described in the IEEE Std
1003.1-2008 (POSIX.1) available from
execute scripts in
<file>/etc/cron.{hourly,daily,weekly,monthly}</file>.
</p>
+
+ <sect1 id="cron-files">
+ <heading>Cron job file names</heading>
+
+ <p>
+ The file name of a cron job file should normally match the
+ name of the package from which it comes.
+ </p>
+
+ <p>
+ If a package supplies multiple cron job files files in the
+ same directory, the file names should all start with the name
+ of the package (possibly modified as described below) followed
+ by a hyphen (<tt>-</tt>) and a suitable suffix.
+ </p>
+
+ <p>
+ A cron job file name must not include any period or plus
+ characters (<tt>.</tt> or <tt>+</tt>) characters as this will
+ cause cron to ignore the file. Underscores (<tt>_</tt>)
+ should be used instead of <tt>.</tt> and <tt>+</tt>
+ characters.
+ </p>
+ </sect1>
</sect>
<sect id="menus">
<sect1>
<heading>Sharing configuration files</heading>
- <p>
- Packages which specify the same file as a
- <tt>conffile</tt> must be tagged as <em>conflicting</em>
- with each other. (This is an instance of the general rule
- about not sharing files. Note that neither alternatives
- nor diversions are likely to be appropriate in this case;
- in particular, <prgn>dpkg</prgn> does not handle diverted
- <tt>conffile</tt>s well.)
- </p>
-
- <p>
- The maintainer scripts must not alter a <tt>conffile</tt>
- of <em>any</em> package, including the one the scripts
- belong to.
- </p>
-
<p>
If two or more packages use the same configuration file
and it is reasonable for both to be installed at the same
and which manages the shared configuration files. (The
<tt>sgml-base</tt> package is a good example.)
</p>
+
+ <p>
+ If the configuration file cannot be shared as described above,
+ the packages must be marked as conflicting with each other.
+ Two packages that specify the same file as
+ a <tt>conffile</tt> must conflict. This is an instance of the
+ general rule about not sharing files. Neither alternatives
+ nor diversions are likely to be appropriate in this case; in
+ particular, <prgn>dpkg</prgn> does not handle diverted
+ <tt>conffile</tt>s well.
+ </p>
+
+ <p>
+ When two packages both declare the same <tt>conffile</tt>, they
+ may see left-over configuration files from each other even
+ though they conflict with each other. If a user removes
+ (without purging) one of the packages and installs the other,
+ the new package will take over the <tt>conffile</tt> from the
+ old package. If the file was modified by the user, it will be
+ treated the same as any other locally
+ modified <tt>conffile</tt> during an upgrade.
+ </p>
+
+ <p>
+ The maintainer scripts must not alter a <tt>conffile</tt>
+ of <em>any</em> package, including the one the scripts
+ belong to.
+ </p>
</sect1>
<sect1>