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atexit
[request execution of functions at
program exit]
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).
COMPLIANCE
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.
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