bsd_signal(3) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | VERSIONS | STANDARDS | HISTORY | SEE ALSO | COLOPHON

bsd_signal(3)           Library Functions Manual           bsd_signal(3)

NAME         top

       bsd_signal - signal handling with BSD semantics

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <signal.h>

       typedef void (*sighandler_t)(int);

       sighandler_t bsd_signal(int signum, sighandler_t handler);

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

       bsd_signal():
           Since glibc 2.26:
               _XOPEN_SOURCE >= 500
                   && ! (_POSIX_C_SOURCE >= 200809L)
           glibc 2.25 and earlier:
               _XOPEN_SOURCE

DESCRIPTION         top

       The bsd_signal() function takes the same arguments, and performs
       the same task, as signal(2).

       The difference between the two is that bsd_signal() is guaranteed
       to provide reliable signal semantics, that is: a) the disposition
       of the signal is not reset to the default when the handler is
       invoked; b) delivery of further instances of the signal is
       blocked while the signal handler is executing; and c) if the
       handler interrupts a blocking system call, then the system call
       is automatically restarted.  A portable application cannot rely
       on signal(2) to provide these guarantees.

RETURN VALUE         top

       The bsd_signal() function returns the previous value of the
       signal handler, or SIG_ERR on error.

ERRORS         top

       As for signal(2).

ATTRIBUTES         top

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

VERSIONS         top

       Use of bsd_signal() should be avoided; use sigaction(2) instead.

       On modern Linux systems, bsd_signal() and signal(2) are
       equivalent.  But on older systems, signal(2) provided unreliable
       signal semantics; see signal(2) for details.

       The use of sighandler_t is a GNU extension; this type is defined
       only if the _GNU_SOURCE feature test macro is defined.

STANDARDS         top

       None.

HISTORY         top

       4.2BSD, POSIX.1-2001.  Removed in POSIX.1-2008, recommending the
       use of sigaction(2) instead.

SEE ALSO         top

       sigaction(2), signal(2), sysv_signal(3), signal(7)

COLOPHON         top

       This page is part of the man-pages (Linux kernel and C library
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Linux man-pages 6.9.1          2024-05-02                  bsd_signal(3)

Pages that refer to this page: signal(2)sysv_signal(3)signal(7)