memcmp.c.svn-base

来自「SumatraPDF是一款小型开源的pdf阅读工具。虽然玲珑小巧（只有800多K」· SVN-BASE 代码 · 共 53 行

/*
    jbig2dec
    
    Copyright (C) 2001-2005 Artifex Software, Inc.
    
    This software is distributed under license and may not
    be copied, modified or distributed except as expressly
    authorized under the terms of the license contained in
    the file LICENSE in this distribution.
                                                                                
    For information on commercial licensing, go to
    http://www.artifex.com/licensing/ or contact
    Artifex Software, Inc.,  101 Lucas Valley Road #110,
    San Rafael, CA  94903, U.S.A., [phone].

    $Id: memcmp.c 461 2008-05-07 21:37:02Z giles $
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stddef.h>

/* replacement for broken memcmp() */

/*
 * compares two byte strings 'a' and 'b', both assumed to be 'len' bytes long
 * returns zero if the two strings are identical, otherwise returns -1 or 1
 * depending on the relative magnitude of the first differing elements,
 * considered as unsigned chars
 */

int memcmp(const void *b1, const void *b2, size_t len)
{
	unsigned char *a, *b;
	size_t i;

	a = (unsigned char *)b1;
	b = (unsigned char *)b2;
	for(i = 0; i < len; i++) {
		if (*a != *b) {
			 /* strings differ */
			return (*a < *b) ? -1 : 1;
		}
		a++;
		b++;
	}

	/* strings match */
	return 0;
}