look up or signal processes based on name and otherattributes
pkill [options] pattern
pgrep looks through the currently running processes and lists the pro-
cess IDs which matches the selection criteria to stdout. All the cri-
teria have to match. For example,
pgrep -u root sshd
will only list the processes called sshd AND owned by root. On the
pgrep -u root,daemon
will list the processes owned by root OR daemon.
pkill will send the specified signal (by default SIGTERM) to each pro-
cess instead of listing them on stdout.