How do I get the parent process ID of a given child process in Linux.

Use ps -o ppid=   e.g. ps -o ppid= 2076 returns 2054, which you can easily use in a script etc. ps -o ppid= -C foo gives the PPID of process with command foo. You can also use the old fashioned ps | grep: ps -eo ppid,comm | grep ‘[f]oo’. Fuller explanation: ps -f 2072 returns UID PID PPID C STIME TTY STAT TIME CMD […]