Linux

#!/bin/bash
#This shell finds the pid of the hawkagent and kills and restarts to put the rulebase into effect
output=`ps aux|grep hawkagent`
#The set -- below helps to parse the above ps output into words and $2 gives the 2nd word which is pid
set -- $output
pid=$2
#Checks if pid of hawkagent exists then kills else starts the hawkagent and exits the program
if [[ $? -eq 0 ]]
then
{
        echo "Kill and start hawkagent if present"
        echo $pid
        kill $pid
        #Wait for 2 seconds for hawkagent to be killed else kill it forcefully if it still exists
        sleep 2
        kill -9 $pid > /dev/null 2>&1
        #Start the hawk agent after killing the existing pid
        nohup ./hawkagent_BWQA &
}
else
{
        echo "Start hawkagent if not present"
        #Start the hawk agent if the hawkagent is not available and exits the program
        nohup ./hawkagent_BWQA &
};
fi
exit

nohup ./hawkagent_BWQA &

if [[ $? -eq 0 ]]

if [[ $? -eq 0 ]]

pid=$2

if [ $# -gt 0 ]

if output=$(ps -ef | grep "h[a]wkagent")
then
  set -- $output
  pid=$2
  ...
else
  ...
fi

if pid=$(pgrep hawkagent)
then 
  ...
else
  ...
fi

if pid=$(ps axopid,comm | grep [h]awkagent)
  then echo "Kill and start hawkagent if present"
       kill ${pid% *}
  else echo "Start hawkagent if not present"
  fi
nohup ./hawkagent_BWQA &

[BWQA]$ ./test.sh >> temp.txt
[BWQA]$ nohup: redirecting stderr to stdout

kill $(ps axopid,comm | grep [h]awkagent | awk '{print $1}')

nohup ./hawkagent_BWQA &

kill $(ps axopid,comm | grep [h]awkagent | awk '{print $1}') | nohup ./opt/tibco/tra/domain/BWQA/hawkagent_BWQA > /dev/null &