NAME

kill − terminate a process with extreme prejudice

SYNOPSIS

kill [ −sig ] processid ... 

DESCRIPTION

Kill sends the TERM (terminate, 15) signal to the specified processes.  If a signal name or number preceded by ’−’ is given as first argument, that signal is sent instead of terminate (see also signal(2)). The list of signal names and numbers is stored in /usr/include/signal.h.  Signals are often referred to by their names, stripped of the common SIG prefix. 

Here is a list of the signal names and numbers.  Signal numbers are not often used directly.  The most common usage of the kill command is simply ”kill” plus the process ID number (see ps(1). 

SIGHUP1hangup
SIGINT2interrupt
SIGQUIT3*quit
SIGILL4*illegal instruction (not reset when caught)
SIGTRAP5*trace trap (not reset when caught)
SIGIOT6*IOT instruction
SIGEMT7*EMT instruction
SIGFPE8*floating point exception
SIGKILL9kill (cannot be caught or ignored)
SIGBUS10*bus error
SIGSEGV11*segmentation violation
SIGSYS12*bad argument to system call
SIGPIPE13write on a pipe with no one to read it
SIGALRM14alarm clock
SIGTERM15software termination signal
16unassigned

N.B.: The starred (*) signals generate a core image if not caught or ignored.

The terminate signal will kill processes that do not catch the signal; "kill −9 ..." is a sure kill, as the KILL (9) signal cannot be caught.  By convention, if process number 0 is specified, all members in the process group (i.e. processes resulting from the current login) are signaled (but beware: this works only if you use sh(1); not if you use csh(1).) In order to be killed, a process must belong to you unless you are the super-user.

The process number of an asynchronous process started with ’&’ is reported by the shell.  Process numbers can also be found by using kill as a built-in to csh(1); See csh(1) for details.

EXAMPLE

kill 124068

stops the process with the I.D. number 124068. 

SEE ALSO

csh(1), ps(1), kill(2), signal(2)

BUGS

An option to kill process groups ala killpg(2) should be provided; a replacement for ”kill 0” for csh(1) users.

7th Edition  —  1/18/82