1 /* $OpenBSD: strcasecmp.c,v 1.5 2003/06/11 21:08:16 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <string.h> 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 #if 0 36 static char sccsid[] = "@(#)strcasecmp.c 8.1 (Berkeley) 6/4/93"; 37 #else 38 static char *rcsid = "$OpenBSD: strcasecmp.c,v 1.5 2003/06/11 21:08:16 deraadt Exp $"; 39 #endif 40 #endif /* LIBC_SCCS and not lint */ 41 42 typedef unsigned char u_char; 43 44 /* 45 * This array is designed for mapping upper and lower case letter 46 * together for a case independent comparison. The mappings are 47 * based upon ascii character sequences. 48 */ 49 static const u_char charmap[] = { 50 '\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007', 51 '\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017', 52 '\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027', 53 '\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037', 54 '\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047', 55 '\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057', 56 '\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067', 57 '\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077', 58 '\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147', 59 '\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157', 60 '\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167', 61 '\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137', 62 '\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147', 63 '\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157', 64 '\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167', 65 '\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177', 66 '\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207', 67 '\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217', 68 '\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227', 69 '\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237', 70 '\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247', 71 '\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257', 72 '\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267', 73 '\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277', 74 '\300', '\301', '\302', '\303', '\304', '\305', '\306', '\307', 75 '\310', '\311', '\312', '\313', '\314', '\315', '\316', '\317', 76 '\320', '\321', '\322', '\323', '\324', '\325', '\326', '\327', 77 '\330', '\331', '\332', '\333', '\334', '\335', '\336', '\337', 78 '\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347', 79 '\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357', 80 '\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367', 81 '\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377', 82 }; 83 84 int 85 strcasecmp(const char *s1, const char *s2) 86 { 87 const u_char *cm = charmap; 88 const u_char *us1 = (const u_char *)s1; 89 const u_char *us2 = (const u_char *)s2; 90 91 while (cm[*us1] == cm[*us2++]) 92 if (*us1++ == '\0') 93 return (0); 94 return (cm[*us1] - cm[*--us2]); 95 } 96 97 int 98 strncasecmp(const char *s1, const char *s2, size_t n) 99 { 100 if (n != 0) { 101 const u_char *cm = charmap; 102 const u_char *us1 = (const u_char *)s1; 103 const u_char *us2 = (const u_char *)s2; 104 105 do { 106 if (cm[*us1] != cm[*us2++]) 107 return (cm[*us1] - cm[*--us2]); 108 if (*us1++ == '\0') 109 break; 110 } while (--n != 0); 111 } 112 return (0); 113 } 114