sysv_signal(3)             Library Functions Manual             sysv_signal(3)

NAME
       sysv_signal - signal handling with System V semantics

LIBRARY
       Standard C library (libc, -lc)

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
       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   |
       +--------------------------------------------+---------------+---------+
       |sysv_signal ()                              | 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)

Linux man-pages 6.7               2023-10-31                    sysv_signal(3)