need a restart server script in 1 hour if not stopped - linux

Question

I am working on a remote servers network setup.
What I need is a script that will rename the "/etc/network/interfaces" file and then restart the computer. The renaming I got but what I don't get is how i can terminate this script in case I don't need it.
See if everything works out fine I like to issue a stop command that will terminate this script, so that the server doesn't restart.
So here is what I got so far. the issues are:
It doesn't return the prompt
The stop command doesn't work. It doesn't get the pid file for some reason. It returns "rm: missing operand" although the echo tells me that the pid file is called "start.pid" and it is present in the /tmp folder
Any ideas?
#! /bin/sh
PATH=/sbin:/usr/sbin:/bin:/usr/bin
. /lib/lsb/init-functions
case "$1" in
start)
;;
export PIDFILE=/var/run/${1}.pid
ps -fe | grep ${1} | head -n1 | cut -d" " -f 6 > ${PIDFILE}
sleep 30 #3600
log_action_msg "WARNING: Will in 60 sec rename /etc/network/interfaces and then restart"
sleep 30# 60
SUFFIX=$(date +%s)
#cp /etc/network/interfaces /etc/network/interfaces.$SUFFIX
cp /tmp/interfaces /etc/network/interfaces.$SUFFIX
sleep 1
#cp /etc/network/interfaces.org /tmp/interfaces
cp /tmp/interfaces.org /tmp/interfaces
sleep 1
#reboot -d -f -i
;;
stop)
if [ -f ${PIDFILE} ]; then
rm ${PIDFILE}
fi
exit 0
;;
*)
echo "Usage: $0 start|stop" >&2
exit 3
;;
esac

Answer 1

Usually this is done using a 'pid-file' - a predetermined file that holds the process identifier of the currently running process. That way if it is called and told to stop, it looks up the pid-file and uses the kill command to send a signal to the currently running process.
There is another benefit of this as well - if you check for the existence of a pid-file (and the existence of that process) when the script is told to start, you can prevent accidentally starting the script twice, which would make stopping both instances problematic.

Answer 2

The stop action can create a file do.not.restart.server in an appropriate location.
The start action can be modified to check whether the do.not.restart.server file exists, and avoid restarting the server if it is. It can/should probably remove the file for future restarts - or maybe it should remove it before it goes to sleep.

Answer 3

Okay, here is a working script, it does what I need. The only improvement I could still wish for is how to return the prompt from the sleep command.
The functionality is there so I am posting it in case others needed as well.
Thanks Dan and Jonathan Leffler for your help and ideas.
#! /bin/sh
PATH=/sbin:/usr/sbin:/bin:/usr/bin
. /lib/lsb/init-functions
export PIDFILESTART=/tmp/network-safty-restart-start.pid
export PIDFILESTOP=/tmp/network-safty-restart-stop.pid
#export FILE=/etc/network/interfaces
export FILE=/tmp/interfaces
case "$1" in
start)
if [ -f ${PIDFILESTART} ]; then
rm ${PIDFILESTART}
fi
if [ -f ${PIDFILESTOP} ]; then
rm ${PIDFILESTOP}
fi
ps -fe | grep ${1} | head -n1 | cut -d" " -f 6 > ${PIDFILESTART}
sleep 3600
log_action_msg "WARNING: Will in 60 sec rename ${FILE} and then restart"
sleep 60
if ! [ -f ${PIDFILESTOP} ]; then
log_action_msg "Restarting NOW"
SUFFIX=$(date +%s)
cp ${FILE} ${FILE}.${SUFFIX}
sleep 1
cp ${FILE}.org ${FILE}
sleep 1
reboot -d -f -i
else
rm ${PIDFILESTOP}
log_action_msg "NOT Restaring as you wish"
fi
;;
stop)
if [ -f ${PIDFILESTART} ]; then
rm ${PIDFILESTART}
ps -fe | grep ${1} | head -n1 | cut -d" " -f 6 > ${PIDFILESTOP}
log_action_msg "Terminating restart script"
fi
log_action_msg "Terminated restart script"
exit 0
;;
*)
echo "Usage: $0 start|stop" >&2
exit 3
;;
esac