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 strcasecmp (const char *@var{s1}, const char *@var{s2})
16
17 A case-insensitive @code{strcmp}.
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 typedef unsigned char uc;
36 static const unsigned char charmap[] = {
37 (uc)'\000',(uc)'\001',(uc)'\002',(uc)'\003',(uc)'\004',(uc)'\005',(uc)'\006',(uc)'\007',
38 (uc)'\010',(uc)'\011',(uc)'\012',(uc)'\013',(uc)'\014',(uc)'\015',(uc)'\016',(uc)'\017',
39 (uc)'\020',(uc)'\021',(uc)'\022',(uc)'\023',(uc)'\024',(uc)'\025',(uc)'\026',(uc)'\027',
40 (uc)'\030',(uc)'\031',(uc)'\032',(uc)'\033',(uc)'\034',(uc)'\035',(uc)'\036',(uc)'\037',
41 (uc)'\040',(uc)'\041',(uc)'\042',(uc)'\043',(uc)'\044',(uc)'\045',(uc)'\046',(uc)'\047',
42 (uc)'\050',(uc)'\051',(uc)'\052',(uc)'\053',(uc)'\054',(uc)'\055',(uc)'\056',(uc)'\057',
43 (uc)'\060',(uc)'\061',(uc)'\062',(uc)'\063',(uc)'\064',(uc)'\065',(uc)'\066',(uc)'\067',
44 (uc)'\070',(uc)'\071',(uc)'\072',(uc)'\073',(uc)'\074',(uc)'\075',(uc)'\076',(uc)'\077',
45 (uc)'\100',(uc)'\141',(uc)'\142',(uc)'\143',(uc)'\144',(uc)'\145',(uc)'\146',(uc)'\147',
46 (uc)'\150',(uc)'\151',(uc)'\152',(uc)'\153',(uc)'\154',(uc)'\155',(uc)'\156',(uc)'\157',
47 (uc)'\160',(uc)'\161',(uc)'\162',(uc)'\163',(uc)'\164',(uc)'\165',(uc)'\166',(uc)'\167',
48 (uc)'\170',(uc)'\171',(uc)'\172',(uc)'\133',(uc)'\134',(uc)'\135',(uc)'\136',(uc)'\137',
49 (uc)'\140',(uc)'\141',(uc)'\142',(uc)'\143',(uc)'\144',(uc)'\145',(uc)'\146',(uc)'\147',
50 (uc)'\150',(uc)'\151',(uc)'\152',(uc)'\153',(uc)'\154',(uc)'\155',(uc)'\156',(uc)'\157',
51 (uc)'\160',(uc)'\161',(uc)'\162',(uc)'\163',(uc)'\164',(uc)'\165',(uc)'\166',(uc)'\167',
52 (uc)'\170',(uc)'\171',(uc)'\172',(uc)'\173',(uc)'\174',(uc)'\175',(uc)'\176',(uc)'\177',
53 (uc)'\200',(uc)'\201',(uc)'\202',(uc)'\203',(uc)'\204',(uc)'\205',(uc)'\206',(uc)'\207',
54 (uc)'\210',(uc)'\211',(uc)'\212',(uc)'\213',(uc)'\214',(uc)'\215',(uc)'\216',(uc)'\217',
55 (uc)'\220',(uc)'\221',(uc)'\222',(uc)'\223',(uc)'\224',(uc)'\225',(uc)'\226',(uc)'\227',
56 (uc)'\230',(uc)'\231',(uc)'\232',(uc)'\233',(uc)'\234',(uc)'\235',(uc)'\236',(uc)'\237',
57 (uc)'\240',(uc)'\241',(uc)'\242',(uc)'\243',(uc)'\244',(uc)'\245',(uc)'\246',(uc)'\247',
58 (uc)'\250',(uc)'\251',(uc)'\252',(uc)'\253',(uc)'\254',(uc)'\255',(uc)'\256',(uc)'\257',
59 (uc)'\260',(uc)'\261',(uc)'\262',(uc)'\263',(uc)'\264',(uc)'\265',(uc)'\266',(uc)'\267',
60 (uc)'\270',(uc)'\271',(uc)'\272',(uc)'\273',(uc)'\274',(uc)'\275',(uc)'\276',(uc)'\277',
61 (uc)'\300',(uc)'\341',(uc)'\342',(uc)'\343',(uc)'\344',(uc)'\345',(uc)'\346',(uc)'\347',
62 (uc)'\350',(uc)'\351',(uc)'\352',(uc)'\353',(uc)'\354',(uc)'\355',(uc)'\356',(uc)'\357',
63 (uc)'\360',(uc)'\361',(uc)'\362',(uc)'\363',(uc)'\364',(uc)'\365',(uc)'\366',(uc)'\367',
64 (uc)'\370',(uc)'\371',(uc)'\372',(uc)'\333',(uc)'\334',(uc)'\335',(uc)'\336',(uc)'\337',
65 (uc)'\340',(uc)'\341',(uc)'\342',(uc)'\343',(uc)'\344',(uc)'\345',(uc)'\346',(uc)'\347',
66 (uc)'\350',(uc)'\351',(uc)'\352',(uc)'\353',(uc)'\354',(uc)'\355',(uc)'\356',(uc)'\357',
67 (uc)'\360',(uc)'\361',(uc)'\362',(uc)'\363',(uc)'\364',(uc)'\365',(uc)'\366',(uc)'\367',
68 (uc)'\370',(uc)'\371',(uc)'\372',(uc)'\373',(uc)'\374',(uc)'\375',(uc)'\376',(uc)'\377',
69 };
70
71 int
72 strcasecmp(const char *s1, const char *s2)
73 {
74 register unsigned char u1, u2;
75
76 for (;;) {
77 u1 = (unsigned char) *s1++;
78 u2 = (unsigned char) *s2++;
79 if (charmap[u1] != charmap[u2]) {
80 return charmap[u1] - charmap[u2];
81 }
82 if (u1 == '\0') {
83 return 0;
84 }
85 }
86 }
87