/*

 * strstr -- locate first occurence of a substring 

 *

 * Locates the first occurrence in the string pointed to by S1 of the string

 * pointed to by S2.  Returns a pointer to the substring found, or a NULL

 * pointer if not found.  If S2 points to a string with zero length, the

 * function returns S1. 

 *

 * For license terms, see the file COPYING in this directory.

 */

char *strstr(register char *buf, register char *sub)

{

    register char *bp;

    if (!*sub)

	return buf;

    for (;;)

    {

	if (!*buf)

	    break;

	bp = buf;

	for (;;)

	{

	    if (!*sub)

		return buf;

	    if (*bp++ != *sub++)

		break;

	}

	sub -= (unsigned long) bp;

	sub += (unsigned long) buf;

	buf += 1;

    }

    return 0;

}