kill(1)								      kill(1)



NAME
  kill - Sends a signal to a running process

SYNOPSIS

  kill -l

  kill [-signal_name | -signal_number] process_ID ...

DESCRIPTION

  The kill command sends a signal to one or more running processes.  The
  default is the SIGTERM signal (signal number 15), which usually terminates
  processes that do not ignore or catch the signal.

  You identify the process to be signaled by specifying its process identifi-
  cation number (also known as the process ID or PID).	The shell displays
  the PID of each process that is running in the background or, if you start
  more than one process in a pipeline, the shell displays the number of the
  last process).  You can also use the ps command to display PIDs.

  The name of the kill command is misleading because many signals, including
  SIGUSR1, do not terminate processes.

  Unless you are operating with superuser authority, the process you wish to
  signal must belong to you.  When operating with superuser authority, you
  can signal any process.

  See the kill() system call for a complete discussion of kill.	 Note that
  the csh command contains a built-in subcommand named kill, but the command
  and subcommand do not necessarily work in the same way.  For information on
  the subcommand, see csh.

  Special Process Identification Numbers

  There are several special process identification numbers (PIDs) that you
  can specify to cause the following special actions:

  0  The signal is sent to all processes having a process group ID equal to
     the process group ID of the sender, except those with PIDs 0 and 1.

  -1 If the effective user ID of the sender is not 0 (root), the signal is
     sent to all processes with a process group ID equal to the effective
     user ID of the sender, except those with PIDs 0 and 1.

     If the effective user ID of the sender is 0 (root), the signal is sent
     to all processes, excluding numbers 0 and 1.

  -PID
     The signal is sent to all processes whose process group number is equal
     to the absolute value of PID.  Note that when you specify any negative
     PID, you must also specify the signal to be sent, even the default sig-
     nal SIGTERM.

FLAGS

  The kill command supports the following flags:

  -l	    Lists signal names.

  -signal_name	|  -signal_number
	    Specifies the signal to send to the process.  You can specify
	    either a name, stripped of the SIG prefix (such as KILL), or a
	    number (such as 9).	 For information about signal names and
	    numbers, see the sigaction() system call.

EXAMPLES

  The following command terminates the process with the specified PID:

       kill 1095


  This command terminates process 1095 by sending it the default SIGTERM sig-
  nal.	Note that process 1095 might not actually terminate if it has made
  special arrangements to ignore or catch the SIGTERM signal.

  The following command terminates several processes that ignore the default
  signal:

       kill -KILL 17285 15692


  This command sends SIGKILL to processes 17285 and 15692.  The SIGKILL sig-
  nal usually cannot be ignored or caught.

  The following command terminates all of your background processes:

       kill 0


  This command sends the SIGTERM signal to all members of the shell process
  group.  This includes all background processes started with &.  Although
  the signal is sent to the shell, it has no effect because the shell ignores
  the default signal 15.

  The following command terminates all of your processes and logs yourself
  out:

       kill -KILL 0


  This command sends SIGKILL to all members of the shell process group.
  Because the shell cannot ignore SIGKILL, this also terminates the login
  shell and logs you out.  If you are using multiple windows, this closes the
  active window.

  The following command terminate all the processes that you own:

       kill -KILL -1


  This command sends SIGKILL to all the processes that you own, even those
  that belong to other process groups.	If you are using multiple windows,
  this command closes all the windows.

  The following command sends a specific signal to a specific process:


       kill -USR1 1103


  This command sends the SIGUSR1 signal to process 1103.  The action taken on
  the SIGUSR1 signal is defined by the particular application you are run-
  ning.

  The following command lists the signal names in numerical order, stripped
  of the SIG prefix:

       kill -l


       HUP INT QUIT ILL TRAP ABRT EMT FPE KILL BUS SEGV SYS PIPE
       ALRM TERM URG STOP TSTP CONT CHLD TTIN TTOU IO XCPU XFSZ
       VTALRM PROF WINCH INFO USR1 USR2


  The command output can vary from system to system.

FILES

  /usr/include/signal.h
	     Specifies signal names.

RELATED INFORMATION

  Commands:  csh(1), killall(8), ksh(1), ps(1), sh(1).

  Functions: kill(2), sigaction(2).