NAME
       kill - send signal to a process



SYNOPSIS
       #include <signal.h>

       int kill(pid_t pid, int sig);



DESCRIPTION
       kill() can be used to send any signal to any process group
       or process.

       If pid is positive, then signal sig is sent  to  pid.   In
       this  case,  0 is returned on success, or a negative value
       on error.

       If pid equals -1, then sig is sent to every process except
       for  the  first one, from higher numbers in the proc table
       to lower.  In this case, 0 is returned on success, or  the
       last error condition from send_sig() is returned.

       If  pid is less than -1, then sig is sent to every process
       in the process group -pid.  In this case,  the  number  of
       processes  the  signal was sent to is returned, or a nega-
       tive value for failure.



RETURN VALUE
       On success, zero is returned.  On error, -1  is  returned,
       and errno is set appropriately.



ERRORS
       EINVAL An invalid signal is sent.

       ESRCH  The pid or process group does not exist.

       EPERM  The  effective userid of the process calling kill()
              is not equal to the effective userid of pid, unless
              the superuser called kill().



BUGS
       It  is impossible to send a signal to task number one, the
       init process, for which it has not installed a signal han-
       dler.   This  is  done to assure the system is not brought
       down accidentally.



CONFORMING TO
       SVID, AT&T, POSIX.1, X/OPEN, BSD 4.3



SEE ALSO
       _exit(2), exit(2), signal(2), signal(7)