60 lines
1.6 KiB
C
60 lines
1.6 KiB
C
/*
|
|
* Copyright (c) 1990 Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* %sccs.include.redist.c%
|
|
*/
|
|
|
|
/*
|
|
FUNCTION
|
|
<<atexit>>---request execution of functions at program exit
|
|
|
|
INDEX
|
|
atexit
|
|
|
|
SYNOPSIS
|
|
#include <stdlib.h>
|
|
int atexit (void (*<[function]>)(void));
|
|
|
|
DESCRIPTION
|
|
You can use <<atexit>> to enroll functions in a list of functions that
|
|
will be called when your program terminates normally. The argument is
|
|
a pointer to a user-defined function (which must not require arguments and
|
|
must not return a result).
|
|
|
|
The functions are kept in a LIFO stack; that is, the last function
|
|
enrolled by <<atexit>> will be the first to execute when your program
|
|
exits.
|
|
|
|
There is no built-in limit to the number of functions you can enroll
|
|
in this list; however, after every group of 32 functions is enrolled,
|
|
<<atexit>> will call <<malloc>> to get space for the next part of the
|
|
list. The initial list of 32 functions is statically allocated, so
|
|
you can always count on at least that many slots available.
|
|
|
|
RETURNS
|
|
<<atexit>> returns <<0>> if it succeeds in enrolling your function,
|
|
<<-1>> if it fails (possible only if no space was available for
|
|
<<malloc>> to extend the list of functions).
|
|
|
|
PORTABILITY
|
|
<<atexit>> is required by the ANSI standard, which also specifies that
|
|
implementations must support enrolling at least 32 functions.
|
|
|
|
Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
|
|
<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include "atexit.h"
|
|
|
|
/*
|
|
* Register a function to be performed at exit.
|
|
*/
|
|
|
|
int
|
|
atexit (void (*fn) (void))
|
|
{
|
|
return __register_exitproc (__et_atexit, fn, NULL, NULL);
|
|
}
|