BSD_SIGNAL
Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
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NAME
bsd_signal - signal handling with BSD semantics
SYNOPSIS
#include <signal.h>
typedef void (*sighandler_t)(int);
sighandler_t bsd_signal(int signum, sighandler_t handler);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
bsd_signal():
-
Since glibc 2.26:
_XOPEN_SOURCE >= 500
&& ! (_POSIX_C_SOURCE >= 200112L)
Glibc 2.25 and earlier:
_XOPEN_SOURCE
DESCRIPTION
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.
RETURN VALUE
The
bsd_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
|
|
bsd_signal()
| Thread safety | MT-Safe
|
CONFORMING TO
4.2BSD, POSIX.1-2001.
POSIX.1-2008 removes the specification of
bsd_signal(),
recommending the use of
sigaction(2)
instead.
NOTES
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 defined only if the
_GNU_SOURCE
feature test macro is defined.
SEE ALSO
sigaction(2),
signal(2),
sysv_signal(3),
signal(7)
COLOPHON
This page is part of release 4.13 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/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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