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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON


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

NAME         top

       bsd_signal - signal handling with BSD semantics

SYNOPSIS         top

       #define _XOPEN_SOURCE
       #include <signal.h>

       typedef void (*sighandler_t)(int);

       sighandler_t bsd_signal(int signum, sighandler_t handler);

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).

CONFORMING TO         top

       4.2BSD, POSIX.1-2001.  POSIX.1-2008 removes the specification of bsd_signal(),
       recommending the use of sigaction(2) instead.

NOTES         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 only defined if the
       _GNU_SOURCE feature test macro is defined.

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 3.23 of the Linux man-pages project.  A
       description of the project, and information about reporting bugs, can be found
       at http://www.kernel.org/doc/man-pages/.

                                      2009-03-15                        BSD_SIGNAL(3)