KILL(2)                  DOMAIN/IX SYS5                   KILL(2)



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

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


DESCRIPTION
     Kill sends a signal to the process or group of processes
     denoted by pid.  The signal is named by sig, and is either
     zero or a number denoting one of the signals described on
     signal(2).  If sig is zero (the null signal), kill performs
     error checking, but does not send a signal.  A zero signal
     is typically used to check the validity of a pid.  The real
     or effective user ID of the sending process must match the
     real or effective user ID of the receiving process, unless
     the effective user ID of the sending process is super-user.

     The process with a process ID of 1 is a special process, and
     is referred to below as proc1.  On DOMAIN Workstations,
     proc1 is always the Display Manager (DM).  On DOMAIN
     Servers, proc1 is always the Server Process Manager (SPM).

     The behavior of kill varies, as shown below, according to
     the value of pid.

     ⊕  If pid is greater than zero, sig is sent to the process
        whose process ID is equal to pid.  Pid may equal 1.

     ⊕  If pid is 0, sig is sent to all processes, except 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 super-user, sig is sent to all processes excluding
        proc1 whose real user ID is equal to the effective user
        ID of the sender.

     ⊕  If pid is -1 and the effective user ID of the sender is
        super-user, sig is sent to all processes excluding proc1.

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

RETURN VALUE
     A successful call returns zero.  A failed call returns -1
     and sets errno as indicated below.




Printed 12/4/86                                            KILL-1

KILL(2)                  DOMAIN/IX SYS5                   KILL(2)



ERRORS
     Kill will fail without sending a signal 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 corresponding to pid can be found.

     [EPERM]   The user ID of the sending process is not super-
               user, and its real or effective user ID does not
               match the real or effective user ID of the receiv-
               ing process.

RELATED INFORMATION
     kill(1), getpid(2), setpgrp(2), signal(2)




































KILL-2                                            Printed 12/4/86