kill(2)                                                   kill(2)



NAME
     kill - sends a signal to a process or a group of processes

SYNOPSIS
     int kill(pid, sig)
     int pid, sig;

DESCRIPTION
     kill sends a signal to a process or a group of processes.
     The process or group of processes to which the signal is
     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(3), 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 effective user ID of the receiving
     process, unless the effective user ID of the sending process
     is the superuser.

     The processes with a process ID of 0 and a process ID of 1
     are special processes (see intro(2)) and will be referred to
     later as proc0 and proc1 respectively.

     If pid is greater than zero, sig will be sent to the process
     whose process ID is equal to pid; pid may equal 1.

     If pid is 0, sig will be sent to all processes excluding
     proc0 and proc1 whose process group ID is equal to the
     process group ID of the sender.

     If pid is -1 and the effective user ID of the sender is not
     the superuser, sig will be sent to all processes excluding
     proc0 and proc1 and to the sender whose real user ID is
     equal to the saved effective user ID of the sender.

     If pid is -1 and the effective user ID of the sender is the
     superuser, sig will be sent to the sender and to all
     processes excluding proc0 and proc1.

     If pid is negative but not -1, sig will be sent to all
     processes whose process group ID is equal to the absolute
     value of pid.

STATUS MESSAGES AND VALUES
     Upon successful completion, a value of 0 is returned.
     Otherwise, a value of -1 is returned and errno is set to
     indicate the error.






January 1992                                                    1

kill(2)                                                   kill(2)



STATUS MESSAGES AND VALUES
     The kill command will fail and no signal will be sent if one
     or more of the following is true.

     EINVAL
          sig is not a valid signal number.

     EINVAL
          sig is SIGKILL and pid is 1 (proc1).

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

     EPERM
          The sending process is not sending to itself, its
          effective user ID is not the superuser, and its real or
          effective user ID does not match the real or effective
          user ID of the receiving process.

SEE ALSO
     getpid(2), setpgrp(2), sigvec(2), signal(3)

     kill(1) in A/UX Command Reference































2                                                    January 1992