NAME

       sigwait - wait for a signal

SYNOPSIS

       #include <signal.h>

        int sigwait(const sigset_t *set, int *sig);

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

       sigwait():
           Since glibc 2.26:
               _POSIX_C_SOURCE >= 199506L
           Glibc 2.25 and earlier:
               _POSIX_C_SOURCE

DESCRIPTION

       The sigwait() function suspends execution of the calling thread until one of the signals specified in the
       signal set set becomes pending.  The function accepts the signal (removes it from  the  pending  list  of
       signals), and returns the signal number in sig.

       The operation of sigwait() is the same as sigwaitinfo(2), except that:

       * sigwait() returns only the signal number, rather than a siginfo_t structure describing the signal.

       * The return values of the two functions are different.

RETURN VALUE

       On success, sigwait() returns 0.  On error, it returns a positive error number (listed in ERRORS).

ERRORS

       EINVAL set contains an invalid signal number.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────┬───────────────┬─────────┐
       │Interface │ Attribute     │ Value   │
       ├──────────┼───────────────┼─────────┤
       │sigwait() │ Thread safety │ MT-Safe │
       └──────────┴───────────────┴─────────┘

CONFORMING TO

       POSIX.1-2001, POSIX.1-2008.

NOTES

       sigwait() is implemented using sigtimedwait(2).

       The  glibc  implementation  of  sigwait() silently ignores attempts to wait for the two real-time signals
       that are used internally by the NPTL threading implementation.  See nptl(7) for details.

EXAMPLE

       See pthread_sigmask(3).

SEE ALSO

       sigaction(2), signalfd(2), sigpending(2), sigsuspend(2), sigwaitinfo(2), sigsetops(3), signal(7)

COLOPHON

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