sigwait(3) — Linux manual page

sigwait(3)              Library Functions Manual              sigwait(3)

NAME

       sigwait - wait for a signal

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <signal.h>

       int sigwait(const sigset_t *restrict set, int *restrict 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.  For a signal to become pending, it must first be
       blocked with sigprocmask(2).  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 │
       └─────────────────────────────────────┴───────────────┴─────────┘

VERSIONS

       sigwait() is implemented using sigtimedwait(2); consult its
       NOTES.

       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.

STANDARDS

       POSIX.1-2008.

HISTORY

       POSIX.1-2001.

EXAMPLES

       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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Linux man-pages 6.9.1          2024-05-02                     sigwait(3)

Pages that refer to this page: kill(2), signalfd(2), sigsuspend(2), sigwaitinfo(2), pthread_sigmask(3), pthread_sigqueue(3), sigqueue(3), nptl(7), signal(7)

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