Java daemon (service) script

#!/bin/bash
#
# chkconfig: 345 99 05
# description: A test service
#
# Derived from -
# Home page: http://www.source-code.biz
# License:   GNU/LGPL (http://www.gnu.org/licenses/lgpl.html)
# Copyright 2006 Christian d'Heureuse, Inventec Informatik AG, Switzerland.
# Copyright 2013 Gabriel Vince, Apogado, Belgium

set -x

if [ -z "$JAVA_HOME" -o "$JAVA_HOME" == " " ]; then
       JAVA_HOME=/usr/java/latest
       export JAVA_HOME
fi

serviceName="program.sh" # service name
serviceUser="gabriel" # OS user name for the service
serviceGroup="users" # OS group name for the service
applDir="/home/gabriel/test/service" # home directory of the service application
serviceUserHome="/home/gabriel"  # home directory of the service user
serviceLogFile="/home/gabriel/test/service/$serviceName.log" # log file for StdO
ut/StdErr
maxShutdownTime=15 # maximum number of seconds to wait for the daemon to termina
te normally
pidFile="/var/run/$serviceName.pid" # name of PID file (PID = process ID number)
cmd="/home/gabriel/test/service/program.sh" # name of the Java launcher without
the path
appname="program.sh" #program name to look for between running processes

# Makes the file $1 writable by the group $serviceGroup.
function makeFileWritable {
   local filename="$1"
   touch $filename || return 1
   chgrp $serviceGroup $filename || return 1
   chmod g+w $filename || return 1
return 0;
}

# Returns 0 if the process with PID $1 is running.
function checkProcessIsRunning {
   local pid="$1"
   if [ -z "$pid" -o "$pid" == " " ]; then return 1; fi
   if [ ! -e /proc/$pid ]; then return 1; fi
   return 0;
}

# Returns 0 if the process with PID $1 is our Java service process.
function checkProcessIsOurService {
   local pid="$1"
   if [ "$(ps -p $pid --no-headers -o comm)" != "$appname" ]; then return 1; fi
   grep -q --binary -F "$appname" /proc/$pid/cmdline
   if [ $? -ne 0 ]; then return 1; fi
   return 0;
}

# Returns 0 when the service is running and sets the variable $pid to the PID.
function getServicePID {
   if [ ! -f $pidFile ]; then return 1; fi
   pid="$(<$pidFile)"
   checkProcessIsRunning $pid || return 1
   checkProcessIsOurService $pid || return 1
   return 0;
}

function startServiceProcess {
   cd $applDir || return 1
   rm -f $pidFile
   makeFileWritable $pidFile || return 1
   makeFileWritable $serviceLogFile || return 1
   cmd="nohup $cmd >>$serviceLogFile 2>&1 & echo \$! >$pidFile"
   su -m $serviceUser -s $SHELL -c "$cmd" || return 1
   sleep 0.1
   pid="$(<$pidFile)"
   if checkProcessIsRunning $pid; then :; else
     echo -ne "\n$serviceName start failed, see logfile."
     return 1
   fi
   return 0;
}

function stopServiceProcess {
   kill $pid || return 1
   for ((i=0; i<maxShutdownTime; i++)); do
      checkProcessIsRunning $pid
      if [ $? -ne 0 ]; then
          rm -f $pidFile
          return 0
     fi
     sleep 1
  done
 echo -e "\n$serviceName did not terminate within $maxShutdownTime seconds, send
ing SIGKILL..."
  kill -s KILL $pid || return 1

  local killWaitTime=15
 for ((i=0; i<killWaitTime; i++)); do
     checkProcessIsRunning $pid
     if [ $? -ne 0 ]; then
         rm -f $pidFile
         return 0
     fi
     sleep 1
     done
     echo "Error: $serviceName could not be stopped within $maxShutdownTime+$kil
lWaitTime seconds!"
     return 1;
}

function startService {
   getServicePID
   if [ $? -eq 0 ]; then echo -n "$serviceName is already running"; RETVAL=0; re
turn 0; fi
   echo -n "Starting $serviceName   "
   startServiceProcess
   if [ $? -ne 0 ]; then RETVAL=1; echo "failed"; return 1; fi
   echo "started PID=$pid"
   RETVAL=0
   return 0;
}

function stopService {
   getServicePID
   if [ $? -ne 0 ]; then echo -n "$serviceName is not running"; RETVAL=0; echo "
"; return 0; fi
   echo -n "Stopping $serviceName   "
   stopServiceProcess
   if [ $? -ne 0 ]; then RETVAL=1; echo "failed"; return 1; fi
       echo "stopped PID=$pid"
       RETVAL=0
   return 0;
}

function checkServiceStatus {
   echo -n "Checking for $serviceName:   "
   if getServicePID; then
      echo "running PID=$pid"
      RETVAL=0
   else
      echo "stopped"
      RETVAL=3
   fi
   return 0;
}


function main {
   RETVAL=0
   case "$1" in
   start) # starts the Java program as a Linux service
      startService
      ;;
   stop)  # stops the Java program service
     stopService
     ;;
   restart) # stops and restarts the service
    stopService && startService
    ;;
  status) # displays the service status
    checkServiceStatus
    ;;
  *)
      echo "Usage: $0 {start|stop|restart|status}"
      exit 1
      ;;
esac
exit $RETVAL
}

main $1