UNIX for Advanced & Expert Users

#!/bin/ksh
set CUR_SHELL="/bin/ksh"
set V1="VAR1"
set V2="VAR2"

ps -e -o args | grep "$CUR_SHELL $1" | tr -s " " | cut -d" " -f1 | 
while read -r V1 V2
do
    if [ "$V1" = "$CUR_SHELL" ]; then
        echo "Error - Program is already running."
        echo "V1 -> $V1"
        exit 1
    fi 
done
echo "V1 -> $V1"
echo "V2 -> $V2"

if [ -z "$V1" ]; then
    echo "V1 IS NULL"
fi

CreateLockFile () {

unset PROCESS_ID
unset ID
LFILE=${TEMP_PATH}/${1}_${TODAYS_DATE}.LCK
ID=$2

if [ -r ${LFILE} ]
 then
    OPID=`cat ${LFILE}` 2> /dev/null
    if [ -z ${OPID} -eq 0 ] #Make Sure OPID contains a value
     then
	 exit ${FAILURE} "ERROR-APP-->: `basename ${LFILE}` exists but contains no Process ID" | tee -a ${INLOG}
     else
        PROCESS_ID=`ps -p ${OPID} | grep ADD-SCRIPT-NAME-HERE | awk -F" " '{print $1}'  2> /dev/null`

        if [ ${PROCESS_ID} ]  #Lock File is there, check if process is actually running
         then
           echo "WARNING-->: ${1} Script Is Currently Running [PID=${OPID}], Exiting. ${DATE_TIME}" | tee -a ${INLOG}
           exit ${SUCCESS}
        else
	  echo "INFO-->: Old Lock File with PID= [ ${OPID} ] Exists But Process Is Not Running. " >> ${INLOG}
	  echo "INFO-->: Overwriting Old PID with New PID Value of [ ${ID} ] " >> ${INLOG}
          echo "$ID" > ${LFILE}
        fi 
     fi
else
  echo "$ID" > ${LFILE}

    if [ $? -ne 0 ]
      then 
        exit ${FAILURE} "ERROR-APP-->: Could Not Create Lock File - Exiting " | tee -a ${INLOG}
    fi
fi
}