bsd_signal(3) Library Functions Manual bsd_signal(3)
NAME
bsd_signal - signal handling with BSD semantics
LIBRARY
Standard C library (libc, -lc)
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 >= 200809L)
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) de-
livery of further instances of the signal is blocked while the signal
handler is executing; and c) if the handler interrupts a blocking sys-
tem 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 han-
dler, 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 │
├────────────────────────────────────────────┼───────────────┼─────────┤
│bsd_signal() │ Thread safety │ MT-Safe │
└────────────────────────────────────────────┴───────────────┴─────────┘
STANDARDS
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)
Linux man-pages 6.03 2023-02-05 bsd_signal(3)
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