Linux man page for atexit.3

atexit(3) -- Linux man page

NAME

atexit - register a function to be called at normal program termination

SYNOPSIS

#include <stdlib.h>

int atexit(void (*function)(void));

DESCRIPTION

The atexit() function registers the given function to be called at normal program termination, either via exit(3) or via return from the program's main(). Functions so registered are called in the reverse order of their registration; no arguments are passed.

At least ATEXIT_MAX functions can be registered. This value is at least 32. It can be obtained using sysconf(3).

By a successful call to one of the exec functions, all registrations are undone.

RETURN VALUE

The atexit() function returns the value 0 if successful; otherwise it returns a nonzero value.

EXAMPLE

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

void bye(void) {
        printf("That was all, folks\n");
}

int main(){
        long a;
        int i;

        a = sysconf(_SC_ATEXIT_MAX);
        printf("ATEXIT_MAX = %ld\n", a);

        i = atexit(bye);
        if (i != 0) {
                fprintf(stderr, "cannot set exit function\n");
                return EXIT_FAILURE;
        }
        return EXIT_SUCCESS;
}

CONFORMING TO

SVID 3, BSD 4.3, ISO 9899, POSIX 1003.1-2001