SYSV_SIGNAL(3) Linux Programmer's Manual SYSV_SIGNAL(3)
NAME
sysv_signal - signal handling with System V semantics
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <signal.h>
typedef void (*sighandler_t)(int);
sighandler_t sysv_signal(int signum, sighandler_t handler);
DESCRIPTION
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 seman-
tics, 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.
RETURN VALUE
The sysv_signal() function returns the previous value of the signal
handler, or SIG_ERR on error.
ERRORS
As for signal(2).
ATTRIBUTES
For an explanation of the terms used in this section, see at-
tributes(7).
+--------------+---------------+---------+
|Interface | Attribute | Value |
+--------------+---------------+---------+
|sysv_signal() | Thread safety | MT-Safe |
+--------------+---------------+---------+
CONFORMING TO
This function is nonstandard.
NOTES
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 defined only
if the _GNU_SOURCE feature test macro is defined.
SEE ALSO
sigaction(2), signal(2), bsd_signal(3), signal(7)
COLOPHON
This page is part of release 5.07 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
https://www.kernel.org/doc/man-pages/.
2017-09-15 SYSV_SIGNAL(3)