To confirm the existence of the process, use the kill command and specify 0 as an option. Rest assured that if you specify the 0 option for kill, the process will not be terminated.
kill -0 process number
If the process exists, the command will succeed and nothing will be output. If the command fails, you will get a message that there is no such process.
This can be confirmed by examining $? . If it succeeds, it will be 0 , and if it fails, it will be 1 .
The following is a sample script.
kill -0 16033 > /dev/null 2>&1 if [ $? = 0 ]; then echo "exists"; else echo "not exists" fi