on_exit(3) — Linux manual page

on_exit(3)              Library Functions Manual              on_exit(3)

NAME

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

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <stdlib.h>

       int on_exit(void (*function)(int, void *), 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

       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

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

ATTRIBUTES

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

STANDARDS

       None.

HISTORY

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

CAVEATS

       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

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

COLOPHON

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

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

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