sigpause - atomically release blocked signals and wait for interrupt

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

       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.

       POSIX.1-2001.  Obsoleted in POSIX.1-2008.

       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).

       Standard C library (libc, -lc)

       sigpause - atomically release blocked signals and wait for interrupt

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

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

Linux man-pages 6.9.1                              2024-06-16                                        sigpause(3)

       POSIX.1-2008.

#include<signal.h>[[deprecated]]intsigpause(intsigmask);/*BSD(butseeVERSIONS)*/[[deprecated]]intsigpause(intsig);/*POSIX.1/SysV/UNIX95*/

       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).