atexit — register a function to be called at normal process termination
#include <stdlib.h>
int
atexit( |
void | (*function)(void)); |
The atexit() function
registers the given function to be called at normal
process termination, either via exit(3) or via return from
the program's main(). Functions
so registered are called in the reverse order of their
registration; no arguments are passed.
POSIX.1-2001 requires that an implementation allow at
least ATEXIT_MAX (32) such
functions to be registered. The actual limit supported by an
implementation can be obtained using sysconf(3).
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.
The atexit() function
returns the value 0 if successful; otherwise it returns a
nonzero value.
Functions registered using atexit() (and on_exit(3)) are not called
if a process terminates abnormally because of the delivery of
a signal.
Since glibc 2.2.3, atexit() (and on_exit(3)) can be used
within a shared library to establish functions that are
called when the shared library is unloaded.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
void
bye(void)
{
printf("That was all, folks\n");
}
int
main(void)
{
long a;
int i;
a = sysconf(_SC_ATEXIT_MAX);
printf("ATEXIT_MAX = %ld\n", a);
i = atexit(bye);
if (i != 0) {
fprintf(stderr, "cannot set exit function\n");
exit(EXIT_FAILURE);
}
exit(EXIT_SUCCESS);
}
This page is part of release 2.79 of the Linux man-pages project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man-pages/.
|
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. References consulted: Linux libc source code Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) 386BSD man pages Modified 1993-03-29, David Metcalfe Modified 1993-07-24, Rik Faith (faithcs.unc.edu) Modified 2003-10-25, Walter Harms |