kill — terminate or signal a process
kill [-s signal_name] pid …
kill -l [exit_status]
kill -signal_name pid …
kill -signal_number pid …
The kill utility sends a signal to the processes specified by the pid operands. Only the super-user may send signals to other users’ processes. The options are as follows:
-s signal_name A symbolic signal name specifying the signal to be sent instead of the default TERM.
-l [exit_status] If no operand is given, list the signal names; otherwise, writethe signal name corresponding to exit_status.
-signal_name A symbolic signal name specifying the signal to be sent instead of the default TERM.
-signal_number A non-negative decimal integer, specifying the signal to be sent instead of the default TERM.
The following PIDs have special meanings:
-1 If superuser, broadcast the signal to all processes; otherwise broadcast to all processes belonging to the user.
Some of the more commonly used signals:
1 HUP (hang up)
2 INT (interrupt)
3 QUIT (quit)
6 ABRT (abort)
9 KILL (non-catchable, non-ignorable kill)
14 ALRM (alarm clock)
15 TERM (software termination signal)
This is copied from the freebsd kill manual from here. It’s copied over here cause i keep forgetting all this crap.