SIGPAUSE(3)                Linux Programmer's Manual               SIGPAUSE(3)

       sigpause - atomically release blocked signals and wait for interrupt

       #include <signal.h>

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

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

       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.

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

       For an explanation of the terms used in this section, see

       │Interface  Attribute     Value   │
       │sigpause() │ Thread safety │ MT-Safe │
       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.

       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)

       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).

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

       This page is part of release 5.06 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

Linux                             2017-09-15                       SIGPAUSE(3)