sysv_signal - signal handling with System V semantics
#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);
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.
The
sysv_signal() function returns the previous value of the signal
handler, or
SIG_ERR on error.
As for
signal(2).
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| sysv_signal () |
Thread safety |
MT-Safe |
This function is nonstandard.
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.
sigaction(2),
signal(2),
bsd_signal(3),
signal(7)