xref: /csrg-svn/lib/libc/string/strcasecmp.c (revision 31747)
131745Sbostic /*
231745Sbostic  * Copyright (c) 1987 Regents of the University of California.
331745Sbostic  * All rights reserved.  The Berkeley software License Agreement
431745Sbostic  * specifies the terms and conditions for redistribution.
531745Sbostic  */
631745Sbostic 
731745Sbostic #if defined(LIBC_SCCS) && !defined(lint)
8*31747Sbostic static char sccsid[] = "@(#)strcasecmp.c	5.2 (Berkeley) 07/02/87";
931745Sbostic #endif LIBC_SCCS and not lint
1031745Sbostic 
1131745Sbostic /*
12*31747Sbostic  * This array is designed for mapping upper and lower case letter
13*31747Sbostic  * together for a case independent comparison.  The mappings are
14*31747Sbostic  * based upon ascii character sequences.
1531745Sbostic  */
16*31747Sbostic static char charmap[] = {
17*31747Sbostic 	'\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
18*31747Sbostic 	'\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
19*31747Sbostic 	'\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
20*31747Sbostic 	'\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
21*31747Sbostic 	'\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
22*31747Sbostic 	'\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
23*31747Sbostic 	'\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
24*31747Sbostic 	'\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
25*31747Sbostic 	'\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
26*31747Sbostic 	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
27*31747Sbostic 	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
28*31747Sbostic 	'\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
29*31747Sbostic 	'\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
30*31747Sbostic 	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
31*31747Sbostic 	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
32*31747Sbostic 	'\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
33*31747Sbostic 	'\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
34*31747Sbostic 	'\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
35*31747Sbostic 	'\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
36*31747Sbostic 	'\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
37*31747Sbostic 	'\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
38*31747Sbostic 	'\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
39*31747Sbostic 	'\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
40*31747Sbostic 	'\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
41*31747Sbostic 	'\300', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
42*31747Sbostic 	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
43*31747Sbostic 	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
44*31747Sbostic 	'\370', '\371', '\372', '\333', '\334', '\335', '\336', '\337',
45*31747Sbostic 	'\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
46*31747Sbostic 	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
47*31747Sbostic 	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
48*31747Sbostic 	'\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
49*31747Sbostic };
50*31747Sbostic 
5131745Sbostic strcasecmp(s1, s2)
52*31747Sbostic 	register char *s1, *s2;
5331745Sbostic {
54*31747Sbostic 	register char *cm = charmap;
5531745Sbostic 
56*31747Sbostic 	while (cm[*s1] == cm[*s2++])
57*31747Sbostic 		if (*s1++ == '\0')
5831745Sbostic 			return(0);
59*31747Sbostic 	return(cm[*s1] - cm[*--s2]);
6031745Sbostic }
6131745Sbostic 
6231745Sbostic strcasencmp(s1, s2, n)
63*31747Sbostic 	register char *s1, *s2;
64*31747Sbostic 	register int n;
6531745Sbostic {
66*31747Sbostic 	register char *cm = charmap;
6731745Sbostic 
68*31747Sbostic 	while (--n >= 0 && cm[*s1] == cm[*s2++])
69*31747Sbostic 		if (*s1++ == '\0')
7031745Sbostic 			return(0);
71*31747Sbostic 	return(n < 0 ? 0 : cm[*s1] - cm[*--s2]);
7231745Sbostic }
73