Bash script to check if process is running

start_blockchain.sh

 #!/bin/bash
 
 BLOCKCHAIN=$1
 MULTICHAIND=multichaind
 
 check_process(){
     if [ "$BLOCKCHAIN" = "" ];
     then
         #echo "No blockchain defined in parameter"
         return 3
     fi  
 
     PROCESS_NUM=$(ps -ef | grep "$MULTICHAIND $BLOCKCHAIN" | grep -v "grep" | wc -l)
     #$PROCESS_NUM
     if [ $PROCESS_NUM -eq 1 ];
     then
         #echo "$BLOCKCHAIN is running"
         return 1
     else
         #echo "$BLOCKCHAIN is not running"
         return 0
     fi  
 }
 
 echo "checking if $BLOCKCHAIN is running..."
 check_process
 CHECK_RETURN=$?
 echo "Result after using check_process - $CHECK_RETURN"
 if [ $CHECK_RETURN -eq 3 ];
 then
     echo "No parameter passed, can't run check"
     exit 1
 elif [ $CHECK_RETURN -eq 0 ];
 then
     echo "$BLOCKCHAIN not started, starting..."
     nohup $MULTICHAIND $BLOCKCHAIN -d &
 else
     echo "$BLOCKCHAIN is already up n running"
 fi