/*
 * Make a string in 'to' which is the same characters as in the string 'from'
 * but in the opposite order.  The area pointed to by 'to' must be as large as
 * required to hold the string in 'from'.
 */
void reverse(char *from, char *to)
{
    int len, i;

    /* find string length */
    for (len = 0; from[len]; len++)
	;

    /* copy, reversing */
    for (i = 0; i < len; i++)
	to[len - i - 1] = from[i];

    /* terminate target string */
    to[len] = '\0';
}

/* There are library functions to do some of the string operations above. */