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NAME

       sigsuspend - wait for a signal

SYNOPSIS

       #include <signal.h>

       int sigsuspend(const sigset_t *mask);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       sigsuspend(): _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE

DESCRIPTION

       sigsuspend()  temporarily  replaces  the  signal  mask  of  the calling
       process with the mask given by mask and then suspends the process until
       delivery  of  a signal whose action is to invoke a signal handler or to
       terminate a process.

       If the signal  terminates  the  process,  then  sigsuspend()  does  not
       return.   If  the signal is caught, then sigsuspend() returns after the
       signal handler returns, and the signal mask is restored  to  the  state
       before the call to sigsuspend().

       It  is  not  possible  to  block  SIGKILL  or SIGSTOP; specifying these
       signals in mask, has no effect on the process’s signal mask.

RETURN VALUE

       sigsuspend() always returns -1, normally with the error EINTR.

ERRORS

       EFAULT mask points to memory which is not a valid part of  the  process
              address space.

       EINTR  The call was interrupted by a signal.

CONFORMING TO

       POSIX.1-2001.

NOTES

       Normally,  sigsuspend()  is  used in conjunction with sigprocmask(2) in
       order to prevent delivery  of  a  signal  during  the  execution  of  a
       critical  code  section.   The  caller  first  blocks  the signals with
       sigprocmask(2).  When the critical code has completed, the caller  then
       waits for the signals by calling sigsuspend() with the signal mask that
       was returned by sigprocmask(2) (in the oldset argument).

       See sigsetops(3) for details on manipulating signal sets.

SEE ALSO

       kill(2),    pause(2),    sigaction(2),    signal(2),    sigprocmask(2),
       sigwaitinfo(2), sigsetops(3), sigwait(3), signal(7)

COLOPHON

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