#! /bin/sh
  counter=0
  zabbix_counter=$(ps -ef | grep zabbix_agentd | grep -v grep | wc -l)

  start(){
  echo "-------------------------------------------------------------------"
  echo " LAUNCHING ZABBIX AGENT"

  if [ $zabbix_counter -gt 0 ]; then
  echo " * Zabbix agent was previously running"
  echo " * Number of Zabbix agentd instances= $zabbix_counter"
  echo "-----------------------------------------------------------------"
  fi

  # Checking if the user is able to start the agent.... if the user is not able to, script performs su to
  # the user zabbix and starts the agent

  if [ $(whoami) != "zabbix" ];then
  sudo -u zabbix zabbix_agentd
  else
  # Script is acting as the zabbix user, so it can start the agent.
  zabbix_agentd
  fi
  sleep 10

  zabbix_counter=$(ps -ef | grep zabbix_agentd | grep -v grep | wc -l)
  if [ $zabbix_counter -gt 0 ]; then
  echo " * Zabbix agent succesfully started"
  echo " * Number of zabbix agentd instances= $zabbix_counter"
  echo "-------------------------------------------------------------------"
  else
  echo " * Zabbix agent couldn't be started, check Zabbix logs"
  echo "-------------------------------------------------------------------"
  fi

  }

  stop(){
  # Checking if the user is able to stop the agent.... if the user is not able to, script performs su to
  # the user zabbix and kills the agent. Also script tries to kill zabbix-agent processes 5 times using a counter, if at
  # the fith try the agent is still there, script outputs a message to the console.

  echo "-------------------------------------------------------------------"
  echo " STOPPING ZABBIX AGENT"

  if [ $zabbix_counter -eq 0 ]; then
  echo " * Zabbix agent was not running on this machine"
  echo "-------------------------------------------------------------------"
  fi

  while [ $zabbix_counter -gt 0 ] && [ $counter -lt 5 ] ; do

  let counter=counter+1

  echo " * Number of Attempts (Max 5)=$counter"
  echo " * Stopping zabbix.."
  echo " * Number of zabbix agentd instances= $zabbix_counter"

  if [ $(whoami) != "zabbix" ];then
  sudo -u zabbix killall zabbix_agentd > /dev/null &
  else
  killall zabbix_agentd > /dev/null &
  fi

  sleep 10
  # Script has a 10 second delay to avoid attempting to kill a process that is still shutting down. If the script
  # can't kill the processes, an error will appear.
  # After 10 seconds script checks again the number of zabbix_agentd processes running,
  # if it's 0, script will exit the loop and continue on

  zabbix_counter=$(ps -ef | grep zabbix_agentd | grep -v grep | wc -l)

  done

  if [ $zabbix_counter -gt 0 ]; then
  echo " * Zabbix agent couldn't be stopped, check Zabbix logs"
  echo "-------------------------------------------------------------------"
  fi

  if [ $zabbix_counter -eq 0 ]; then
  echo " * Zabbix agent successfully stopped"
  echo "-------------------------------------------------------------------"
  fi

  }

  restart(){
  stop
  # Gives system some time to stop processes before script restarts service
  sleep 10
  # Now script can start the agent again
  start
  }

  case "$1" in
  start)
  start
  ;;
  stop)
  stop
  ;;
  restart)
  restart
  ;;
  *)
  echo "Usage: zabbix {start|stop|restart}"
  exit 1
  esac

  exit 0