kill(2) 							   System Calls 							   kill(2)

NAME

       kill - send a signal to a process or a group of processes

SYNOPSIS

       #include <sys/types.h>
       #include <signal.h>

       int kill(pid_t pid, int sig);

DESCRIPTION

       The  kill()  function  sends  a signal to a process or a group of processes. The process or group of processes to which the signal is to be
       sent is specified by pid. The signal that is to be sent is specified by sig and is either one from the  list  given  in	signal	(see  sig-
       nal.h(3HEAD)),  or  0. If sig is 0 (the null signal), error checking is performed but no signal is actually sent. This can be used to check
       the validity of pid.

       The real or effective user ID of the sending process must match the real or saved (from one of functions in the exec(2) family) user ID	of
       the  receiving  process,  unless the privilege {PRIV_PROC_OWNER} is asserted in the effective set of the sending process (see intro(2)), or
       sig is SIGCONT and the sending process  has  the  same  session	ID  as	the  receiving	process.  A  process  needs  the  basic  privilege
       {PRIV_PROC_SESSION} to send signals to a process with a different session ID. See privileges(5).

       If pid is greater than 0, sig will be sent to the process whose process ID is equal to  pid.

       If  pid	is  negative but not (pid_t)-1, sig will be sent to all processes whose process group ID is equal to the absolute value of pid and
       for which the process has permission to send a signal.

       If pid is 0, sig will be sent to all processes excluding special processes (see intro(2)) whose process group ID is equal  to  the  process
       group ID of the sender.

       If  pid	is  (pid_t)-1 and the {PRIV_PROC_OWNER} privilege is not asserted in the effective set of the sending process, sig will be sent to
       all processes excluding special processes whose real user ID is equal to the effective user ID of the sender.

       If pid is (pid_t)-1 and the {PRIV_PROC_OWNER} privilege is asserted in the effective set of the sending process, sig will be  sent  to  all
       processes excluding special processes.

RETURN VALUES

       Upon successful completion, 0 is returned. Otherwise, -1 is returned, no signal is sent, and errno is set to indicate the error.

ERRORS

       The kill() function will fail if:

       EINVAL	       The sig argument is not a valid signal number.

       EPERM	       The  sig  argument  is  SIGKILL and the pid argument is (pid_t)-1 (that is, the calling process does not have permission to
		       send the signal to any of the processes specified by pid).

		       The effective user of the calling process does not match the real or saved user and the calling process does not  have  the
		       {PRIV_PROC_OWNER}  privilege  asserted  in  the	effective  set, and the calling process either is not sending SIGCONT to a
		       process that shares the same session ID or does not have the {PRIV_PROC_SESSION} privilege asserted and is trying to send a
		       signal to a process with a different session ID.

       ESRCH	       No process or process group can be found corresponding to that specified by pid.

USAGE

       The sigsend(2) function provides a more versatile way to send signals to processes.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Signal-Safe 	   |
       +-----------------------------+-----------------------------+

SEE ALSO

       kill(1),  intro(2), exec(2), getpid(2), getsid(2), setpgrp(2), sigaction(2), sigsend(2), signal(3C), signal.h(3HEAD), attributes(5), privi-
       leges(5), standards(5)

SunOS 5.10							    22 Mar 2004 							   kill(2)