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bsd_signal(3) — Linux manual page

bsd_signal(3) Library Functions Manual bsd_signal(3)

NAME top

 bsd_signal - signal handling with BSD semantics

LIBRARY top

 Standard C library (libc, -lc)

SYNOPSIS top

 #include <signal.h>
 typedef typeof(void (int)) *sighandler_t;
 sighandler_t bsd_signal(int signum, sighandler_t handler);
 Feature Test Macro Requirements for glibc (see
 feature_test_macros(7)):
 bsd_signal():
 Since glibc 2.26:
 _XOPEN_SOURCE >= 500
 && ! (_POSIX_C_SOURCE >= 200809L)
 glibc 2.25 and earlier:
 _XOPEN_SOURCE

DESCRIPTION top

 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 top

 The bsd_signal() function returns the previous value of the signal
 handler, or SIG_ERR on error.

ERRORS top

 As for signal(2).

ATTRIBUTES top

 For an explanation of the terms used in this section, see
 attributes(7).
 ┌──────────────────────────────────────┬───────────────┬─────────┐
 │ Interface │ Attribute │ Value │
 ├──────────────────────────────────────┼───────────────┼─────────┤
 │ bsd_signal() │ Thread safety │ MT-Safe │
 └──────────────────────────────────────┴───────────────┴─────────┘

VERSIONS top

 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 defined
 only if the _GNU_SOURCE feature test macro is defined.

STANDARDS top

 None.

HISTORY top

 4.2BSD, POSIX.1-2001. Removed in POSIX.1-2008, recommending the
 use of sigaction(2) instead.

SEE ALSO top

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

COLOPHON top

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Linux man-pages 6.10 2024年12月13日 bsd_signal(3)

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

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