Name
sysv_signal - signal handling with System V semanticsLibrary
Standard C library ( libc ", " -lc )Synopsis
"#define(7)_GNU_SOURCE" " /* See feature_test_macros */" #include <signal.h> typedef void (*sighandler_t)(int); 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 |
| T} | Thread safety | MT-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)