kill [ -s signal_name | -n signal_number | -sig ] job ...
kill -l [ sig ... ]
       Sends either SIGTERM or the specified signal to the given jobs or
       processes.  Signals are given by number or by names, with or
       without the `SIG' prefix.  If the signal being sent is not `KILL'
       or `CONT', then the job will be sent a `CONT' signal if it is
       stopped.  The argument job can be the process ID of a job not in
       the job list.  In the second form, kill -l, if sig is not
       specified the signal names are listed.  Otherwise, for each sig
       that is a name, the corresponding signal number is listed.  For
       each sig that is a signal number or a number representing the exit
       status of a process which was terminated or stopped by a signal
       the name of the signal is printed.

       On some systems, alternative signal names are allowed for a few
       signals.  Typical examples are SIGCHLD and SIGCLD or SIGPOLL and
       SIGIO, assuming they correspond to the same signal number.  kill
       -l will only list the preferred form, however kill -l alt will
       show if the alternative form corresponds to a signal number.  For
       example, under Linux kill -l IO and kill -l POLL both output 29,
       hence kill -IO and kill -POLL have the same effect.

       Many systems will allow process IDs to be negative to kill a
       process group or zero to kill the current process group.
