kill(2) — svr4 — mips UMIPS RISC/os 5.01



KILL(2-SVR4)        RISC/os Reference Manual         KILL(2-SVR4)



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

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

     int kill (pidt pid, int 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 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 signal(5)], or 0.  If sig is 0 (the null sig-
     nal), 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 exec(2)] user ID of the
     receiving process unless the effective user ID of the send-
     ing process is superuser, [see intro(2)], or sig is SIGCONT
     and the sending process has the same session ID as the
     receiving process.

     The process with ID 0 and the process with ID 1 are special
     processes [see intro(2)] and will be referred to below as
     proc0 and proc1, respectively.

     If pid is greater than 0, sig will be sent to the process
     whose process ID is equal to pid.  pid may equal 1.

     If pid is negative but not (pid_t)-1, sig will be sent to
     all processes whose process group ID is equal to the abso-
     lute 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
     proc0 and proc1 whose process group ID is equal to the pro-
     cess group ID of the sender.  Permission is needed to send a
     signal to process groups.

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

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





                        Printed 11/19/92                   Page 1



KILL(2-SVR4)        RISC/os Reference Manual         KILL(2-SVR4)



     kill will fail and no signal will be sent if one or more of
     the following are true:

     EINVAL         sig is not a valid signal number.

     EINVAL         sig is SIGKILL and pid is (pid_t)1 (i.e., pid
                    specifies proc1).

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

     EPERM          The user ID of the sending process is not
                    privileged, and its real or effective user ID
                    does not match the real or saved user ID of
                    the receiving process, and the calling pro-
                    cess is not sending SIGCONT to a process that
                    shares the same session ID.

SEE ALSO
     getpid(2), intro(2), setpgrp(2), signal(2), getsid(2), sig-
     send(2), sigaction(2).
     kill(1) in the User's Reference Manual.

NOTES
     sigsend is a more versatile way to send signals to
     processes.  The user is encouraged to use sigsend instead of
     kill.

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned.  Oth-
     erwise, a value of -1 is returned and errno is set to indi-
     cate the error.























 Page 2                 Printed 11/19/92

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