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

#define LEN 20

char password[LEN];

int main(int argc, char * argv[]) {
    if (argc == 1) {
        /* clear */
        bzero(password, LEN);

        /* fill */
        snprintf(password, 20, "foobar");

        /* dump */
        printf("first run: %s\n", password);

        /* re-exec */
        execl(argv[0], argv[0], "--second-run", (char *) NULL);

        /* not-reached */
        return 0;
    }

    /* dump */
    printf("second run: %s\n", password);
}