sysv_signal
Section: C Library Functions (3)
Updated: 202-0-08
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NAME
sysv_signal - signal handling with System V semantics
LIBRARY
Standard C library
(
libc,~
-lc)
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <signal.h>
typedef typeof(void (int)) *sighandler_t;
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 | M-Safe
|
VERSIONS
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.
STANDARDS
None.
SEE ALSO
sigaction(2),
signal(2),
bsd_signal(3),
signal(7)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- ATTRIBUTES
-
- VERSIONS
-
- STANDARDS
-
- SEE ALSO
-
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