OpenSolaris_b135/lib/libmail/common/casncmp.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
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 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
/*	  All Rights Reserved  	*/

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 *  NAME
 *	casncmp - compare strings ignoring case
 *
 *  SYNOPSIS
 *	int casncmp(char *s1, char *s2, ssize_t n)
 *
 *  DESCRIPTION
 *	Compare two strings ignoring case differences.
 *	Stop after n bytes or the trailing NUL.
 */

#include "libmail.h"
#include <ctype.h>
#include <sys/types.h>

int
casncmp(char *s1, char *s2, ssize_t n)
{
	if (s1 == s2)
		return (0);
	while ((--n >= 0) && (tolower(*s1) == tolower(*s2))) {
		s2++;
		if (*s1++ == '\0')
			return (0);
	}
	return ((n < 0)? 0: (*s1 - *s2));
}