1 /* 2 * Copyright (c) 1987 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that this notice is preserved and that due credit is given 7 * to the University of California at Berkeley. The name of the University 8 * may not be used to endorse or promote products derived from this 9 * software without specific written prior permission. This software 10 * is provided ``as is'' without express or implied warranty. 11 */ 12 13 /* 14 15 @deftypefn Supplemental int strncasecmp (const char *@var{s1}, const char *@var{s2}) 16 17 A case-insensitive @code{strncmp}. 18 19 @end deftypefn 20 21 */ 22 23 #if defined(LIBC_SCCS) && !defined(lint) 24 static char sccsid[] = "@(#)strcasecmp.c 5.5 (Berkeley) 11/24/87"; 25 #endif /* LIBC_SCCS and not lint */ 26 27 #include <ansidecl.h> 28 #include <stddef.h> 29 30 /* 31 * This array is designed for mapping upper and lower case letter 32 * together for a case independent comparison. The mappings are 33 * based upon ascii character sequences. 34 */ 35 static const unsigned char charmap[] = { 36 '\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007', 37 '\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017', 38 '\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027', 39 '\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037', 40 '\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047', 41 '\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057', 42 '\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067', 43 '\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077', 44 '\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147', 45 '\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157', 46 '\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167', 47 '\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137', 48 '\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147', 49 '\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157', 50 '\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167', 51 '\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177', 52 '\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207', 53 '\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217', 54 '\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227', 55 '\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237', 56 '\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247', 57 '\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257', 58 '\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267', 59 '\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277', 60 '\300', '\341', '\342', '\343', '\344', '\345', '\346', '\347', 61 '\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357', 62 '\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367', 63 '\370', '\371', '\372', '\333', '\334', '\335', '\336', '\337', 64 '\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347', 65 '\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357', 66 '\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367', 67 '\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377', 68 }; 69 70 int 71 strncasecmp(const char *s1, const char *s2, register size_t n) 72 { 73 register unsigned char u1, u2; 74 75 for (; n != 0; --n) { 76 u1 = (unsigned char) *s1++; 77 u2 = (unsigned char) *s2++; 78 if (charmap[u1] != charmap[u2]) { 79 return charmap[u1] - charmap[u2]; 80 } 81 if (u1 == '\0') { 82 return 0; 83 } 84 } 85 return 0; 86 } 87
