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

NAME

     sysv_signal - signal handling with System V semantics

SYNOPSIS

     #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);

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).

ATTRIBUTES

     For  an  explanation  of  the  terms  used   in   this   section,   see
     attributes(7).

     +--------------+---------------+---------+
     |Interface     | Attribute     | Value   |
     +--------------+---------------+---------+
     |sysv_signal() | Thread safety | MT-Safe |
     +--------------+---------------+---------+

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 defined only
     if the _GNU_SOURCE feature test macro is defined.

SEE ALSO

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

COLOPHON

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     latest    version    of    this    page,    can     be     found     at
     https://www.kernel.org/doc/man-pages/.

                                2017-09-15                    SYSV_SIGNAL(3)