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 ar-
       gument  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 correspond-
       ing  signal  number is listed.  For each sig that is a signal number
       or a number representing the exit status of a process which was ter-
       minated or stopped by a signal the name of the signal is printed.

       On some systems, alternative signal names are allowed for a few sig-
       nals.  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.
