sysv_signal — signal handling with System V semantics
#define _GNU_SOURCE #include <signal.h> typedef void (*sighandler_t)(int);
sighandler_t sysv_signal( |
int | signum, |
sighandler_t | handler) ; |
The sysv_signal
() function
takes the same arguments, and performs the same task, as
signal(2).
However sysv_signal
()
provides the System V unreliable signal semantics, that is:
a) the disposition of the signal is reset to the default when
the handler is invoked; b) delivery of further instances of
the signal is not blocked while the signal handler is
executing; and c) if the handler interrupts (certain)
blocking system calls, then the system call is not
automatically restarted.
The sysv_signal
() function
returns the previous value of the signal handler, or
SIG_ERR
on error.
Use of sysv_signal
() should
be avoided; use sigaction(2) instead.
On older Linux systems, sysv_signal
() and signal(2) were equivalent.
But on newer systems, signal(2) provides reliable
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 2.79 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/.
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 Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date.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. |