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

SIGSETOPS(3) Library Functions Manual SIGSETOPS(3)

NAME top

   sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX
   signal set operations

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#include <signal.h>**

   **int sigemptyset(sigset_t ***_set_**);**
   **int sigfillset(sigset_t ***_set_**);**

   **int sigaddset(sigset_t ***_set_**, int** _signum_**);**
   **int sigdelset(sigset_t ***_set_**, int** _signum_**);**

   **int sigismember(const sigset_t ***_set_**, int** _signum_**);**

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

   **sigemptyset**(), **sigfillset**(), **sigaddset**(), **sigdelset**(),
   **sigismember**():
       _POSIX_C_SOURCE

DESCRIPTION top

   These functions allow the manipulation of POSIX signal sets.

   **sigemptyset**() initializes the signal set given by _set_ to empty,
   with all signals excluded from the set.

   **sigfillset**() initializes _set_ to full, including all signals.

   **sigaddset**() and **sigdelset**() add and delete respectively signal
   _signum_ from _set_.

   **sigismember**() tests whether _signum_ is a member of _set_.

   Objects of type _sigsett_ must be initialized by a call to either
   **sigemptyset**() or **sigfillset**() before being passed to the functions
   **sigaddset**(), **sigdelset**(), and **sigismember**() or the additional
   glibc functions described below (**sigisemptyset**(), **sigandset**(), and
   **sigorset**()).  The results are undefined if this is not done.

RETURN VALUE top

   **sigemptyset**(), **sigfillset**(), **sigaddset**(), and **sigdelset**() return 0
   on success and -1 on error.

   **sigismember**() returns 1 if _signum_ is a member of _set_, 0 if _signum_
   is not a member, and -1 on error.

   On error, these functions set _[errno](../man3/errno.3.html)_ to indicate the error.

ERRORS top

   **EINVAL** _signum_ is not a valid signal.

ATTRIBUTES top

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

VERSIONS top

GNU If the _GNU_SOURCE feature test macro is defined, then <signal.h> exposes three other functions for manipulating signal sets:

   **int sigisemptyset(const sigset_t ***_set_**);**
   **int sigorset(sigset_t ***_dest_**, const sigset_t ***_left_**,**
                 **const sigset_t ***_right_**);**
   **int sigandset(sigset_t ***_dest_**, const sigset_t ***_left_**,**
                 **const sigset_t ***_right_**);**

   **sigisemptyset**() returns 1 if _set_ contains no signals, and 0
   otherwise.

   **sigorset**() places the union of the sets _left_ and _right_ in _dest_.
   **sigandset**() places the intersection of the sets _left_ and _right_ in
   _dest_.  Both functions return 0 on success, and -1 on failure.

   These functions are nonstandard (a few other systems provide
   similar functions) and their use should be avoided in portable
   applications.

STANDARDS top

   POSIX.1-2008.

HISTORY top

   POSIX.1-2001.

NOTES top

   When creating a filled signal set, the glibc **sigfillset**() function
   does not include the two real-time signals used internally by the
   NPTL threading implementation.  See [nptl(7)](../man7/nptl.7.html) for details.

SEE ALSO top

   [sigaction(2)](../man2/sigaction.2.html), [sigpending(2)](../man2/sigpending.2.html), [sigprocmask(2)](../man2/sigprocmask.2.html), [sigsuspend(2)](../man2/sigsuspend.2.html)

COLOPHON top

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Linux man-pages 6.10 2024-07-23 SIGSETOPS(3)

Pages that refer to this page:sigaction(2), signal(2), signalfd(2), sigpending(2), sigprocmask(2), sigsuspend(2), sigwaitinfo(2), pthread_attr_setsigmask_np(3), pthread_sigmask(3), sigwait(3), nptl(7), signal(7), signal-safety(7)