SYSV_SIGNAL
Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
Page Index
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 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.
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
attributes(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
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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/.