-c     Suppress normal output; instead print a count of matching processes.

-d delimiter
       Sets the string used to delimit each process ID in the output (by default a newline).  (pgrep
       only.)

-f     The pattern is normally only matched against the process name.  When -f is set, the full command
       line is used.

-g pgrp,...
       Only match processes in the process group IDs listed.  Process group 0 is translated into pgrep's
       or pkill's own process group.

-G gid,...
       Only match processes whose real group ID is listed.  Either the numerical or symbolical value may
       be used.

-l     List the process name as well as the process ID. (pgrep only.)

-n     Select only the newest (most recently started) of the matching processes.

-o     Select only the oldest (least recently started) of the matching processes.

-P ppid,...
       Only match processes whose parent process ID is listed.

-s sid,...
       Only match processes whose process session ID is listed.  Session ID 0 is translated into pgrep's
       or pkill's own session ID.

-t term,...
       Only match processes whose controlling terminal is listed.  The terminal name should be specified
       without the "/dev/" prefix.

-u euid,...
       Only match processes whose effective user ID is listed.  Either the numerical or symbolical value
       may be used.

-U uid,...
       Only match processes whose real user ID is listed.  Either the numerical or symbolical value may
       be used.

-v     Negates the matching.

-x     Only match processes whose name (or command line if -f is specified) exactly match the pattern.

-signal
       Defines the signal to send to each matched process.  Either the numeric or the symbolic signal
       name can be used.  (pkill only.)