sysv_signal - signal handling with System V semantics
#define _GNU_SOURCE /* See feature_test_macros(7) */
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.
For an explanation of the terms used in this section, see attributes(7).
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.
This page is part of release 5.13 of the Linux man-pages project. A
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version of this page, can be found at https://www.kernel.org/doc/man-pages/.