sigwait(3) - Linux manual page (original) (raw)

sigwait(3) Library Functions Manual sigwait(3)

NAME top

   sigwait - wait for a signal

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#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 top

   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)](../man2/sigprocmask.2.html).  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)](../man2/sigwaitinfo.2.html), except
   that:

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

   •  The return values of the two functions are different.

RETURN VALUE top

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

ERRORS top

   **EINVAL** _set_ contains an invalid signal number.

ATTRIBUTES top

   For an explanation of the terms used in this section, see
   [attributes(7)](../man7/attributes.7.html).
   ┌──────────────────────────────────────┬───────────────┬─────────┐
   │ **Interface** │ **Attribute** │ **Value** │
   ├──────────────────────────────────────┼───────────────┼─────────┤
   │ **sigwait**()                            │ Thread safety │ MT-Safe │
   └──────────────────────────────────────┴───────────────┴─────────┘

VERSIONS top

   **sigwait**() is implemented using [sigtimedwait(2)](../man2/sigtimedwait.2.html); 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)](../man7/nptl.7.html) for details.

STANDARDS top

   POSIX.1-2008.

HISTORY top

   POSIX.1-2001.

EXAMPLES top

   See [pthread_sigmask(3)](../man3/pthread%5Fsigmask.3.html).

SEE ALSO top

   [sigaction(2)](../man2/sigaction.2.html), [signalfd(2)](../man2/signalfd.2.html), [sigpending(2)](../man2/sigpending.2.html), [sigsuspend(2)](../man2/sigsuspend.2.html),
   [sigwaitinfo(2)](../man2/sigwaitinfo.2.html), [sigsetops(3)](../man3/sigsetops.3.html), [signal(7)](../man7/signal.7.html)

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Linux man-pages 6.10 2024-07-23 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)