SYSV_SIGNAL(3)		   Linux Programmers Manual	       SYSV_SIGNAL(3)



NAME
       sysv_signal - signal handling with System V semantics

SYNOPSIS
       #define _GNU_SOURCE
       #include 

       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	seman
       tics, 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).

CONFORMING TO
       This function is non-standard.

NOTES
       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  only  defined
       if the _GNU_SOURCE feature test macro is defined.

SEE ALSO
       sigaction(2),  signal(2),  bsd_signal(3),  feature_test_macros(7), sig
       nal(7)

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



				  2007-05-04			SYSV_SIGNAL(3)