Configuration of System V init under Debian GNU/Linux
Most Unix versions have a file here that describes how the scripts
in this directory work, and how the links in the /etc/rc?.d/ directories
influence system startup/shutdown.
For Debian, this information is contained in the policy manual, chapter
"System run levels and init.d scripts". The Debian Policy Manual is
available at:
http://www.debian.org/doc/debian-policy/#contentsThe Debian Policy Manual is also available in the Debian package
"debian-policy". When this package is installed, the policy manual can be
found in directory /usr/share/doc/debian-policy. If you have a browser
installed you can probably read it at
file://localhost/usr/share/doc/debian-policy/
Some more detailed information can also be found in the files in the
/usr/share/doc/sysv-rc directory.
Debian Policy dictates that /etc/init.d/*.sh scripts must work properly
when sourced. The following additional rules apply:
* /etc/init.d/*.sh scripts must not rely for their correct functioning
on their being sourced rather than executed. That is, they must work
properly when executed too. They must include "#!/bin/sh" at the top.
This is useful when running scripts in parallel.
* /etc/init.d/*.sh scripts must conform to the rules for sh scripts as
spelled out in the Debian policy section entitled "Scripts" (§10.4).
Use the update-rc.d command to create symbolic links in the /etc/rc?.d
as appropriate. See that man page for more details.
All init.d scripts are expected to have a LSB style header documenting
dependencies and default runlevel settings. The header look like this
(not all fields are required):
### BEGIN INIT INFO
# Provides: skeleton
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Should-Start: $portmap
# Should-Stop: $portmap
# X-Start-Before: nis
# X-Stop-After: nis
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# X-Interactive: true
# Short-Description: Example initscript
# Description: This file should be used to construct scripts to be
# placed in /etc/init.d.
### END INIT INFO
More information on the format is available from insserv(
. This
information is used to dynamicaly assign sequence numbers to the
boot scripts and to run the scripts in parallel during the boot.
See also /usr/share/doc/insserv/README.Debian.