atexit() -- General Function (libc)

Register a function to be called when the program exits
#include <stdlib.h>
int atexit(void (function)
void (*function)();

atexit()  registers one  or more  functions to be  called when  the program
exits.   These  registered functions  can,  for  example, perform  clean-up
beyond what  is ordinarily  performed when  a program exits.   atexit() can
register up to 32 functions.

function points to the function  to be called.  A registered function takes
no arguments and returns nothing.

The functions  that atexit()  registers are  called when the  program exits
normally, i.e., when the function  exit() is called or when main() returns.
They are called in reverse order of registration.

atexit() returns  zero if function  could be registered, and  a value other
than zero if it could not.

Example

This  example registers  two  functions to  be executed  upon exiting:  one
displays a message, and the other  waits for the user to press a key before
terminating.

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

void
lastgasp()
{
    fprintf(stderr, "Type return to continue");
}

void
get1()
{
    getchar();
}

main()
{
    /* set up get1() as last exit routine */
    atexit(get1);
    /* set up lastgasp() as exit routine */
    atexit(lastgasp);

    /* exit, which invokes exit routines */
    exit(EXIT_SUCCESS);
}

See Also

exit(),
libc
ANSI Standard, §7.10.4.2

© 2012 by Stephen A. Ness