Listing 1: rc script to call the sentinel program

#!/bin/sh
#######################################################################
###                     /etc/init.d/sentinel                        ###
### This is the rc script used to start the "sentinel" program kept ###
### in "/usr/bill/progs".       Notice the use of "at" to delay the ###
### start of the  program  till after the  machine  is up for a few ###
### minutes.                                                        ###
#######################################################################

case $1 in
     'start')
       echo /usr/bill/progs/sentinel | at now +5 minutes   ### set delay
       exit 0
       ;;
     'stop')
       exit 0                                              ### no action
       ;;
     *)
       exit 1                                              ### error
       ;;
esac

