Manual Pages for UNIX Operating System command usage for man sigqueue

Standard C Library Functions                         sigqueue(3C)



NAME
     sigqueue - queue a signal to a process

SYNOPSIS
     #include 
     #include 

     int sigqueue(pid_t pid, int signo, const union sigval value);


DESCRIPTION
     The sigqueue() function causes the signal specified by signo
     to  be sent with the value specified by value to the process
     specified by pid. If signo is 0  (the  null  signal),  error
     checking  is  performed  but no signal is actually sent. The
     null signal can be used to check the validity of pid.


     The conditions required for a process to have permission  to
     queue  a  signal  to another process are the same as for the
     kill(2) function.


     The sigqueue() function returns immediately.  If  SA_SIGINFO
     is  set  for  signo  and  if the resources were available to
     queue the signal, the signal  is  queued  and  sent  to  the
     receiving  process. If SA_SIGINFO is not set for signo, then
     signo is sent at least once to the receiving process; it  is
     unspecified whether value will be sent to the receiving pro-
     cess as a result of this call.


     If the value of pid causes signo to  be  generated  for  the
     sending process, and if signo is not blocked for the calling
     thread and if no other thread  has  signo  unblocked  or  is
     waiting  in a sigwait(2) function for signo, either signo or
     at least the pending, unblocked signal will be delivered  to
     the  calling  thread before the sigqueue() function returns.
     Should any of multiple pending signals in the range SIGRTMIN
     to  SIGRTMAX be selected for delivery, it will be the lowest
     numbered one. The selection order between realtime and  non-
     realtime  signals,  or between multiple pending non-realtime
     signals, is unspecified.

RETURN VALUES
     Upon successful completion, the specified signal  will  have
     been  queued, and the sigqueue() function returns  0. Other-
     wise, the function returns -1 and sets errno to indicate the
     error.

ERRORS




SunOS 5.11           Last change: 5 Feb 2008                    1






Standard C Library Functions                         sigqueue(3C)



     The sigqueue() function will fail if:

     EAGAIN     No resources are available to queue  the  signal.
                The  process has already queued SIGQUEUE_MAX sig-
                nals that are still pending at  the  receiver(s),
                or   a   system  wide  resource  limit  has  been
                exceeded.


     EINVAL     The value of signo is an invalid  or  unsupported
                signal number.


     ENOSYS     The sigqueue() function is not supported  by  the
                system.


     EPERM      The  process  does  not  have   the   appropriate
                privilege  to  send  the  signal to the receiving
                process.


     ESRCH      The process pid does not exist.


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    | ATTRIBUTE TYPE              | ATTRIBUTE VALUE             |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | Async-Signal-Safe           |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     kill(2), siginfo.h(3HEAD), signal.h(3HEAD), sigwaitinfo(3C),
     attributes(5), standards(5)










SunOS 5.11           Last change: 5 Feb 2008                    2