如何利用shell开发keepalived启动脚本

#!/bin/bash
## Define variables
RETVAL=0
Conf="/data/apps/keepalived/etc/keepalived/keepalived.conf"
Exce="/data/apps/keepalived/sbin/keepalived"
Pid="/data/apps/keepalived/run/keepalived.pid"
# Determine the user to execute
if [ "$UID" -ne "$RETVAL" ];then
 echo "Must be root to run scripts"
 exit 1
fi
# Load local functions library
[ -f /etc/init.d/functions ] && source /etc/init.d/functions
# Define functions
start(){
 if [ ! -f "$Pid" ];then
 $Exce -f $Conf -p $Pid >/dev/null 2>&1
 RETVAL=$"Start keepalived service" /bin/true
    else
  action "Start keepalived service" /bin/false
 fi
 else
 echo "keepalived service is running"
 fi
 return $RETVAL
}
stop(){
 if [ -f "$Pid" ];then
   kill $(cat $Pid) >/dev/null 2>&1
 RETVAL=$"Stop keepalived service" /bin/true
    else
  action "Stop keepalived service" /bin/false
 fi
 else
 echo "keepalived service is not running"
 fi
 return $RETVAL
}
status(){
 if [ -f "$Pid" ];then
   echo "keepalived service is running"
 else
 echo "keepalived service is not running"
 fi
 return $RETVAL
}
# case local functions
case "$1" in
 start)
 start
 RETVAL=$"USAGE:$0{status|start|stop|restart}"
   exit 1 
esac
# Scripts return values
exit $RETVAL