string/strcasecmp.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1987, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  */
  54
  55 #include <sys/cdefs.h>
  56 #include <string.h>
  57
  58 #if defined(LIBC_SCCS) && !defined(lint)
  59 static char sccsid[] = "@(#)strcasecmp.c        8.1 (Berkeley) 6/4/93";
  60 #endif /* LIBC_SCCS and not lint */
  61
  62 typedef unsigned char u_char;
  63
  64 /*
  65  * This array is designed for mapping upper and lower case letter
  66  * together for a case independent comparison.  The mappings are
  67  * based upon ascii character sequences.
  68  */
  69 static const u_char charmap[] = {
  70         '\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
  71         '\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
  72         '\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
  73         '\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
  74         '\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
  75         '\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
  76         '\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
  77         '\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
  78         '\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
  79         '\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
  80         '\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
  81         '\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
  82         '\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
  83         '\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
  84         '\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
  85         '\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
  86         '\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
  87         '\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
  88         '\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
  89         '\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
  90         '\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
  91         '\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
  92         '\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
  93         '\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
  94         '\300', '\301', '\302', '\303', '\304', '\305', '\306', '\307',
  95         '\310', '\311', '\312', '\313', '\314', '\315', '\316', '\317',
  96         '\320', '\321', '\322', '\323', '\324', '\325', '\326', '\327',
  97         '\330', '\331', '\332', '\333', '\334', '\335', '\336', '\337',
  98         '\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
  99         '\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
 100         '\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
 101         '\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
 102 };
 103
 104 int
 105 strcasecmp(s1, s2)
 106         const char *s1, *s2;
 107 {
 108         register const u_char *cm = charmap,
 109                         *us1 = (const u_char *)s1,
 110                         *us2 = (const u_char *)s2;
 111
 112         while (cm[*us1] == cm[*us2++])
 113                 if (*us1++ == '\0')
 114                         return (0);
 115         return (cm[*us1] - cm[*--us2]);
 116 }
 117
 118 int
 119 strncasecmp(s1, s2, n)
 120         const char *s1, *s2;
 121         register size_t n;
 122 {
 123         if (n != 0) {
 124                 register const u_char *cm = charmap,
 125                                 *us1 = (const u_char *)s1,
 126                                 *us2 = (const u_char *)s2;
 127
 128                 do {
 129                         if (cm[*us1] != cm[*us2++])
 130                                 return (cm[*us1] - cm[*--us2]);
 131                         if (*us1++ == '\0')
 132                                 break;
 133                 } while (--n != 0);
 134         }
 135         return (0);
 136 }