sysv_signal(3) [linux man page]

SYSV_SIGNAL(3)						     Linux Programmer's Manual						    SYSV_SIGNAL(3)

NAME

       sysv_signal - signal handling with System V semantics

SYNOPSIS

       #define _GNU_SOURCE
       #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).

CONFORMING TO

       This function is nonstandard.

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), signal(7)

COLOPHON

       This page is part of release 3.27 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)

BSD_SIGNAL(3)						     Linux Programmer's Manual						     BSD_SIGNAL(3)

NAME

       bsd_signal - signal handling with BSD semantics

SYNOPSIS

       #define _XOPEN_SOURCE	   /* See feature_test_macros(7) */
       #include <signal.h>

       typedef void (*sighandler_t)(int);

       sighandler_t bsd_signal(int signum, sighandler_t handler);

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) delivery of further instances of the signal is blocked while the  signal
       handler is executing; and c) if the handler interrupts a blocking system 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 handler, or SIG_ERR on error.

ERRORS

       As for signal(2).

CONFORMING TO

       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 only defined if the _GNU_SOURCE feature test macro is defined.

SEE ALSO

       sigaction(2), signal(2), sysv_signal(3), signal(7)

COLOPHON

       This  page is part of release 3.44 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/.

								    2009-03-15							     BSD_SIGNAL(3)