Init script

Debian uses a Sys-V like init system for executing shell scripts when the system runlevel changes. How to do?

• /etc/init.d/xxx (xxx : your init script)
• update-rc xxx

 
Adding symbolic links to cause the script to be executed when the system goes down, or comes up.

The example of script executed as init.

• The script is just a  shell script with  'Switch case ' statement.

..................................................................................................................

#! /bin/sh
# /etc/init.d/blah
#

# Some things that run always
touch /var/lock/blah

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting script blah "
    echo "Could do more here"
    ;;
  stop)
    echo "Stopping script blah"
    echo "Could do more here"
    ;; 

  restart|reload)

    $0 stop
    sleep 3
    $0 start

  ;;

  *)

    echo "Usage: /etc/init.d/blah {start|stop}"
    exit 1
    ;;
esac

exit 0

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reference:

1. http://www.debian-administration.org/articles/28