sysv_signal(3) — Linux manual page

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)

COLOPHON

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Linux man-pages 6.9.1          2024-05-02                 sysv_signal(3)

Pages that refer to this page: signal(2), bsd_signal(3), signal(7)

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