Shell Programming and Scripting

Hi,
I'm develpoing a shell script which takes backup for an Oracle database. Requirement is, the script should exit when it find another instance of the same script being run on the server. I'm not able to perform the check using the shell script name using ps command.

when i use ps command I'm not able to get the script name currently executing. Not sure how I can overcome this. I searched this forum for any similar posts, but couldnt find the solution.

Please help!

you can touch a temp file and use its existence as a check for instance.

Code:

CheckInstance() {
 
 if [ -f "$(basename $0).lock" ]; then
  echo "Another instance of $0 already running."
  exit 1
 else
  touch $(basename $0).lock
 fi
}
 
CleanLock() {
 rm -f $(basename $0).lock
 }

 
## MAIN
CheckInstance # check for lock
 
## do your work here
 
CleanLock # clean lock at the end

another way (to put at the beginning of the script)

Code:

if pidof -x -o $$ $(basename "$0")
then
    echo "Another instance of $0 already running."
    exit 1
fi

Thank you all. This will surely help me..