atexit

register functions to be called when the program terminates normally

Synopsis:

#include <stdlib.h>
int atexit( void (*func)(void) );

Description:

The atexit() function is passed the address of function func to be called when the program terminates normally. Successive calls to atexit() create a list of functions that will be executed on a “last-in, first-out” basis. No more than 32 functions can be registered with the atexit() function.

The functions have no parameters and do not return values.

The functions registered with atexit() aren't called when the program is terminated by a call to _exit().

Returns:

0
if the registration succeeds,
non-zero
if it fails.

See also:

abort(), _exit(), exit()

Examples:

#include <stdio.h>
#include <stdlib.h>

void main()
  {
    void func1(void), func2(void), func3(void);

    atexit( func1 );
    atexit( func2 );
    atexit( func3 );
    printf( "Do this first.\n" );
  }

void func1(void) { printf( "last.\n" ); }

void func2(void) { printf( "this " ); }

void func3(void) { printf( "Do " ); }

produces the output: 

Do this first.
Do this last.

Classification:

ANSI

Systems:

All (except Netware, DOS/PM)