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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