bsd_signal — signal handling with BSD semantics
#define _XOPEN_SOURCE #include <signal.h> typedef void (*sighandler_t)(int);
sighandler_t bsd_signal( |
int signum, |
sighandler_t handler); |
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.
The bsd_signal() function
returns the previous value of the signal handler, or
SIG_ERR on error.
4.2BSD, POSIX.1-2001. POSIX.1-2008 removes the
specification of bsd_signal(),
recommending the use of sigaction(2) instead.
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.
This page is part of release 3.24 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/.
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Copyright (c) 2007 Michael Kerrisk <mtk.manpagesgmail.com> Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. |