strncasecmp.h

来自「VC视频对象的跟踪提取原代码（vc视频监控源码）」· C头文件 代码 · 共 105 行

// nts: changed to C++ style parameter format
// nts: renamed from .c to .h and added #ifndef __STRNCASECMP_H__ etc
#ifndef __STRNCASECMP_H__
#define __STRNCASECMP_H__

/*
 * Copyright (c) 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that this notice is preserved and that due credit is given
 * to the University of California at Berkeley. The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific written prior permission. This software
 * is provided ``as is'' without express or implied warranty.
 */

/*
  
@deftypefn Supplemental int strncasecmp (const char *@var{s1}, const char *@var{s2})

A case-insensitive @code{strncmp}.

@end deftypefn

*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strcasecmp.c	5.5 (Berkeley) 11/24/87";
#endif /* LIBC_SCCS and not lint */

#include <ansidecl.h>
#ifdef __STDC__
#include <stddef.h>
#else
#define size_t unsigned long
#endif

#ifndef __STRCASECMP_H__   // do not redefine this table
/*
 * This array is designed for mapping upper and lower case letter
 * together for a case independent comparison.  The mappings are
 * based upon ascii character sequences.
 */

// cast to unsigned char without taking up too much space when doing it 256 times
#define unch (unsigned char)
static const unsigned char charmap[] = {
	unch '\000',unch '\001',unch '\002',unch '\003',unch '\004',unch '\005',unch '\006',unch '\007',
	unch '\010',unch '\011',unch '\012',unch '\013',unch '\014',unch '\015',unch '\016',unch '\017',
	unch '\020',unch '\021',unch '\022',unch '\023',unch '\024',unch '\025',unch '\026',unch '\027',
	unch '\030',unch '\031',unch '\032',unch '\033',unch '\034',unch '\035',unch '\036',unch '\037',
	unch '\040',unch '\041',unch '\042',unch '\043',unch '\044',unch '\045',unch '\046',unch '\047',
	unch '\050',unch '\051',unch '\052',unch '\053',unch '\054',unch '\055',unch '\056',unch '\057',
	unch '\060',unch '\061',unch '\062',unch '\063',unch '\064',unch '\065',unch '\066',unch '\067',
	unch '\070',unch '\071',unch '\072',unch '\073',unch '\074',unch '\075',unch '\076',unch '\077',
	unch '\100',unch '\141',unch '\142',unch '\143',unch '\144',unch '\145',unch '\146',unch '\147',
	unch '\150',unch '\151',unch '\152',unch '\153',unch '\154',unch '\155',unch '\156',unch '\157',
	unch '\160',unch '\161',unch '\162',unch '\163',unch '\164',unch '\165',unch '\166',unch '\167',
	unch '\170',unch '\171',unch '\172',unch '\133',unch '\134',unch '\135',unch '\136',unch '\137',
	unch '\140',unch '\141',unch '\142',unch '\143',unch '\144',unch '\145',unch '\146',unch '\147',
	unch '\150',unch '\151',unch '\152',unch '\153',unch '\154',unch '\155',unch '\156',unch '\157',
	unch '\160',unch '\161',unch '\162',unch '\163',unch '\164',unch '\165',unch '\166',unch '\167',
	unch '\170',unch '\171',unch '\172',unch '\173',unch '\174',unch '\175',unch '\176',unch '\177',
	unch '\200',unch '\201',unch '\202',unch '\203',unch '\204',unch '\205',unch '\206',unch '\207',
	unch '\210',unch '\211',unch '\212',unch '\213',unch '\214',unch '\215',unch '\216',unch '\217',
	unch '\220',unch '\221',unch '\222',unch '\223',unch '\224',unch '\225',unch '\226',unch '\227',
	unch '\230',unch '\231',unch '\232',unch '\233',unch '\234',unch '\235',unch '\236',unch '\237',
	unch '\240',unch '\241',unch '\242',unch '\243',unch '\244',unch '\245',unch '\246',unch '\247',
	unch '\250',unch '\251',unch '\252',unch '\253',unch '\254',unch '\255',unch '\256',unch '\257',
	unch '\260',unch '\261',unch '\262',unch '\263',unch '\264',unch '\265',unch '\266',unch '\267',
	unch '\270',unch '\271',unch '\272',unch '\273',unch '\274',unch '\275',unch '\276',unch '\277',
	unch '\300',unch '\341',unch '\342',unch '\343',unch '\344',unch '\345',unch '\346',unch '\347',
	unch '\350',unch '\351',unch '\352',unch '\353',unch '\354',unch '\355',unch '\356',unch '\357',
	unch '\360',unch '\361',unch '\362',unch '\363',unch '\364',unch '\365',unch '\366',unch '\367',
	unch '\370',unch '\371',unch '\372',unch '\333',unch '\334',unch '\335',unch '\336',unch '\337',
	unch '\340',unch '\341',unch '\342',unch '\343',unch '\344',unch '\345',unch '\346',unch '\347',
	unch '\350',unch '\351',unch '\352',unch '\353',unch '\354',unch '\355',unch '\356',unch '\357',
	unch '\360',unch '\361',unch '\362',unch '\363',unch '\364',unch '\365',unch '\366',unch '\367',
	unch '\370',unch '\371',unch '\372',unch '\373',unch '\374',unch '\375',unch '\376',unch '\377',
};
#undef unch

#endif

static int
strncasecmp(const char *s1, const char *s2, register size_t n)
{
    register unsigned char u1, u2;

    for (; n != 0; --n) {
	u1 = (unsigned char) *s1++;
	u2 = (unsigned char) *s2++;
	if (charmap[u1] != charmap[u2]) {
	    return charmap[u1] - charmap[u2];
	}
	if (u1 == '\0') {
	    return 0;
	}
    }
    return 0;
}

#endif