Name

sigwait — wait for a signal

Synopsis

        #include <signal.h>
int sigwait( const sigset_t *set,
  int *sig);
 
[Note] Note
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

This page is part of release 4.12 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man−pages/.


  Copyright (c) 2008, Linux Foundation, written by Michael Kerrisk
    <mtk.manpagesgmail.com>

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