1 /*
2 * Copyright (c) 1990 Regents of the University of California.
3 * All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 *
7 * This function is a modified version of atexit.c
8 */
9
10 /*
11 FUNCTION
12 <<on_exit>>---request execution of function with argument at program exit
13
14 INDEX
15 on_exit
16
17 SYNOPSIS
18 #include <stdlib.h>
19 int on_exit (void (*<[function]>)(int, void *), void *<[arg]>);
20
21 DESCRIPTION
22 You can use <<on_exit>> to enroll functions in a list of functions that
23 will be called when your program terminates normally. The argument is
24 a pointer to a user-defined function which takes two arguments. The
25 first is the status code passed to exit and the second argument is of type
26 pointer to void. The function must not return a result. The value
27 of <[arg]> is registered and passed as the argument to <[function]>.
28
29 The functions are kept in a LIFO stack; that is, the last function
30 enrolled by <<atexit>> or <<on_exit>> will be the first to execute when
31 your program exits. You can intermix functions using <<atexit>> and
32 <<on_exit>>.
33
34 There is no built-in limit to the number of functions you can enroll
35 in this list; however, after every group of 32 functions is enrolled,
36 <<atexit>>/<<on_exit>> will call <<malloc>> to get space for the next part
37 of the list. The initial list of 32 functions is statically allocated, so
38 you can always count on at least that many slots available.
39
40 RETURNS
41 <<on_exit>> returns <<0>> if it succeeds in enrolling your function,
42 <<-1>> if it fails (possible only if no space was available for
43 <<malloc>> to extend the list of functions).
44
45 PORTABILITY
46 <<on_exit>> is a non-standard glibc extension
47
48 Supporting OS subroutines required: None
49 */
50
51 #include <stddef.h>
52 #include <stdlib.h>
53 #include "atexit.h"
54
55 /*
56 * Register a function to be performed at exit.
57 */
58
59 int
on_exit(void (* fn)(int,void *),void * arg)60 on_exit (void (*fn) (int, void *),
61 void *arg)
62 {
63 return __register_exitproc (__et_onexit, (void (*)(void)) fn, arg, NULL);
64 }
65
