NAME

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

SYNOPSIS

#include <stdlib.h>

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

DESCRIPTION

The atexit() function registers the given function to be called at normal process 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.

POSIX.1 requires that an implementation allow at least ATEXIT_MAX (32) process termination functions to be registered. The actual limit supported by an implementation can be obtained using sysconf(3).

Upon a successful call to one of the exec functions, the registrations of all process termination functions are removed.

RETURN VALUE

The atexit() function returns the value 0 if successful; otherwise it returns a non-zero 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

SEE ALSO

_exit(3), exit(3), on_exit(3)