    Send the processes named by PID (or JOBSPEC) the signal SIGSPEC.  If
    SIGSPEC is not present, then SIGTERM is assumed.  An argument of `-l'
    lists the signal names; if arguments follow `-l' they are assumed to
    be signal numbers for which names should be listed.  Kill is a shell
    builtin for two reasons: it allows job IDs to be used instead of
    process IDs, and, if you have reached the limit on processes that
    you can create, you don't have to start a process to kill another one.
