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on_exit(3) — Linux manual page

on_exit(3) Library Functions Manual on_exit(3)

NAME top

 on_exit - register a function to be called at normal process
 termination

LIBRARY top

 Standard C library (libc, -lc)

SYNOPSIS top

 #include <stdlib.h>
 int on_exit(typeof(void (int, void *)) *function, void *arg);
 Feature Test Macro Requirements for glibc (see
 feature_test_macros(7)):
 on_exit():
 Since glibc 2.19:
 _DEFAULT_SOURCE
 glibc 2.19 and earlier:
 _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION top

 The on_exit() function registers the given function to be called
 at normal process termination, whether via exit(3) or via return
 from the program's main(). The function is passed the status
 argument given to the last call to exit(3) and the arg argument
 from on_exit().
 The same function may be registered multiple times: it is called
 once for each registration.
 When a child process is created via fork(2), it inherits copies of
 its parent's registrations. Upon a successful call to one of the
 exec(3) functions, all registrations are removed.

RETURN VALUE top

 The on_exit() function returns the value 0 if successful;
 otherwise it returns a nonzero value.

ATTRIBUTES top

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

STANDARDS top

 None.

HISTORY top

 SunOS 4, glibc. Removed in Solaris (SunOS 5). Use the standard
 atexit(3) instead.

CAVEATS top

 By the time function is executed, stack (auto) variables may
 already have gone out of scope. Therefore, arg should not be a
 pointer to a stack variable; it may however be a pointer to a heap
 variable or a global variable.

SEE ALSO top

 _exit(2), atexit(3), exit(3)

COLOPHON top

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 user-space interface documentation) project. Information about
 the project can be found at 
 ⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
 for this manual page, see
 ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
 This page was obtained from the tarball man-pages-6.10.tar.gz
 fetched from
 ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
 2025年02月02日. If you discover any rendering problems in this HTML
 version of the page, or you believe there is a better or more up-
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 man-pages@man7.org
Linux man-pages 6.10 2024年12月13日 on_exit(3)

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Pages that refer to this page: execve(2), _exit(2), abort(3), atexit(3), exit(3)

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