pidof

NAME
       pidof -- find the process ID of a running program.

SYNOPSIS
       pidof [-s] [-c] [-x] [-o omitpid] [-o omitpid..]  program [program..]

DESCRIPTION
       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. In that case these scripts are located in /etc/rc?.d, where ?  is  the  run‐
       level. If the system has a start-stop-daemon (8) program that should be used instead.

OPTIONS
       -s     Single shot - this instructs the program to only return one pid.

       -c     Only return process ids that are running with the same root directory.  This option is ignored for non-root users, as they will be unable to check
              the current root directory of processes they do not own.

       -x     Scripts too - this causes the program to also return process id's of shells running the named scripts.

       -o omitpid
              Tells pidof to omit processes with that process id. The special pid %PPID can be used to name the parent process of the pidof  program,  in  other
              words the calling shell or shell script.

EXIT STATUS
       0      At least one program was found with the requested name.

       1      No program was found with the requested name.