Linux "pidof" Command Line Options and Examples
find the process ID of a running program.
Pidof finds the process id's (pids) of the named programs. It prints those id's on the standard output. This program is on some systems used in run-level change scripts, especially when the system has a System-V like rc structure.
Usage:
pidof [-s] [-c] [-n] [-x] [-o omitpid[,omitpid..]] [-o omitpid[,omitpid..]..] program [program..]
Command Line Options:
-s
Single shot - this instructs the program to only return one pid.
pidof -s ...
-x
Scripts too - this causes the program to also return process id's of shells running the named scripts.
pidof -x ...
-o
Tells pidof to omit processes with that process id. The special pid %PPID can be used to name the par‐ent process of the pidof program, in other words the calling shell or shell script.EXIT STATUS0 At least one program was found with the requested name.1 No program was found with the requested name.NOTESpidof is actually the same program as killall5; the program behaves according to the name under which it iscalled.When pidof is invoked with a full pathname to the program it should find the pid of, it is reasonably safe.Otherwise it is possible that it returns pids of running programs that happen to have the same name as theprogram you're after but are actually other programs. Note that that the executable name of running processesis calculated with readlink(2), so symbolic links to executables will also match.
pidof -o ...