NAME

       sigpause - atomically release blocked signals and wait for interrupt

SYNOPSIS

       #include <signal.h>

       int sigpause(int sigmask);  /* BSD (but see NOTES) */

       int sigpause(int sig);      /* System V / UNIX 95 */

DESCRIPTION

       Don't use this function.  Use sigsuspend(2) instead.

       The  function  sigpause() is designed to wait for some signal.  It changes the process's signal mask (set
       of blocked signals), and then waits for a signal to arrive.  Upon  arrival  of  a  signal,  the  original
       signal mask is restored.

RETURN VALUE

       If sigpause() returns, it was interrupted by a signal and the return value is -1 with errno set to EINTR.

ATTRIBUTES

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

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

CONFORMING TO

       The  System  V  version  of  sigpause()  is  standardized  in  POSIX.1-2001.   It  is  also  specified in
       POSIX.1-2008, where it is marked obsolete.

NOTES

   History
       The classical BSD version of this function appeared in 4.2BSD.  It sets  the  process's  signal  mask  to
       sigmask.  UNIX 95 standardized the incompatible System V version of this function, which removes only the
       specified signal sig from the process's signal mask.  The unfortunate  situation  with  two  incompatible
       functions  with  the same name was solved by the sigsuspend(2) function, that takes a sigset_t * argument
       (instead of an int).

   Linux notes
       On Linux, this routine is a system call only on the Sparc (sparc64) architecture.

       Glibc uses the BSD version if the _BSD_SOURCE feature test macro is defined and  none  of  _POSIX_SOURCE,
       _POSIX_C_SOURCE, _XOPEN_SOURCE, _GNU_SOURCE, or _SVID_SOURCE is defined.  Otherwise, the System V version
       is used, and feature test macros must be defined as follows to obtain the declaration:

       *  Since glibc 2.26: _XOPEN_SOURCE >= 500

       *  Glibc 2.25 and earlier: _XOPEN_SOURCE

       Since glibc 2.19, only the System V version is exposed by <signal.h>; applications that formerly used the
       BSD sigpause() should be amended to use sigsuspend(2).

SEE ALSO

       kill(2), sigaction(2), sigprocmask(2), sigsuspend(2), sigblock(3), sigvec(3), feature_test_macros(7)

COLOPHON

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