kill — terminate a process
− signal |
−s signal |
−p ] [
−q value ] [
−−] pid | name...
−l [number] |
The command kill sends the specified
signal to the
specified processes or process groups. If no signal is
specified, the TERM signal is sent. This TERM signal will
kill processes that do not catch it; for other processes it
may be necessary to use the KILL signal (number 9), since
this signal cannot be caught.
Most modern shells have a builtin kill function, with a
usage rather similar to that of the command described here.
−−queue options, and
the possibility to specify processes by command name, are
signal is 0,
then no actual signal is sent, but error checking is still
The list of processes to be signaled can be a mixture of names and pids.
be one of four things:
nis larger than 0. The process with pid
All processes in the current process group are signaled.
All processes with a pid larger than 1 are signaled.
nis larger than 1. All processes in process group
nare signaled. When an argument of the form '-n' is given, and it is meant to denote a process group, either a signal must be specified first, or the argument must be preceded by a '--' option, otherwise it will be taken as the signal to send.
All processes invoked using this
name will be
The signal to send. It may be given as a name or a number.
Print a list of signal names, or convert the given
signal number to a name. The signals can be found in
it will print signal names and their corresponding
Do not restrict the commandname-to-pid conversion to processes with the same uid as the present process.
Only print the process id (pid) of the named processes, do not send any signals.
option is automatically enabled when the kill command is
invoked with the name of
pid. This functionality
is deprecated, and will be removed in March 2016.
Print pid(s) that will be signaled with kill along with the signal.
Use sigqueue(2) rather
than kill(2). The
is an integer that is sent along with the signal. If
the receiving process has installed a handler for this
signal using the SA_SIGINFO flag to sigaction(2), then it
can obtain this data via the si_sigval field of the
It is not possible to send a signal to an explicitly selected thread in a multithreaded process using the kill(2) syscall. If kill(2) is used to send a signal to a thread group, then the kernel selects an arbitrary member of the thread group that has not blocked the signal. For more details see clone(2), the CLONE_THREAD description.
The command kill(1) as well as syscall kill(2) accept a TID (thread ID, see gettid(2)) as an argument. In this case the kill behavior is not changed and the signal is also delivered to the thread group rather than to the specified thread.
kill has the following return codes:
partial success (when more than one process specified)
The kill command is part of the util-linux package and is available from Linux Kernel Archive
Copyright 1994 Salvatore Valente (svalentemit.edu)
Copyright 1992 Rickard E. Faith (faithcs.unc.edu)
May be distributed under the GNU General Public License