/* This is not a complete program. */

FILE *file_open(char name[], char access_mode[]) {
    FILE *f;
    char message_buf[80];
    f = fopen(name, access_mode);
    if (f == NULL) {        /* error? */
        int e = errno;      /* Save any error number set by fopen. */
        /* Library function perror prints an informative message. */
        sprintf(message_buf, "Cannot open file \"%.60s\"", name);
        errno = e;          /* Restore error number */
        perror(message_buf);
        exit(EXIT_FAILURE); /* Terminate after printing error message. */
    }
    return f;               /* Only happens if fopen succeeded. */
}