1 /* $NetBSD: strcasecmp.c,v 1.1.1.1 2016/01/13 03:15:30 christos Exp $ */
2
3 /* strcasecmp.c -- case insensitive string comparator
4 Copyright (C) 1998, 1999 Free Software Foundation, Inc.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
19
20 #if HAVE_CONFIG_H
21 # include <config.h>
22 #endif
23
24 #ifdef LENGTH_LIMIT
25 # define STRXCASECMP_FUNCTION strncasecmp
26 # define STRXCASECMP_DECLARE_N , size_t n
27 # define LENGTH_LIMIT_EXPR(Expr) Expr
28 #else
29 # define STRXCASECMP_FUNCTION strcasecmp
30 # define STRXCASECMP_DECLARE_N /* empty */
31 # define LENGTH_LIMIT_EXPR(Expr) 0
32 #endif
33
34 #include <sys/types.h>
35 #include <ctype.h>
36
37 #define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
38
39 /* Compare {{no more than N characters of }}strings S1 and S2,
40 ignoring case, returning less than, equal to or
41 greater than zero if S1 is lexicographically less
42 than, equal to or greater than S2. */
43
44 int
STRXCASECMP_FUNCTION(const char * s1,const char * s2 STRXCASECMP_DECLARE_N)45 STRXCASECMP_FUNCTION (const char *s1, const char *s2 STRXCASECMP_DECLARE_N)
46 {
47 register const unsigned char *p1 = (const unsigned char *) s1;
48 register const unsigned char *p2 = (const unsigned char *) s2;
49 unsigned char c1, c2;
50
51 if (p1 == p2 || LENGTH_LIMIT_EXPR (n == 0))
52 return 0;
53
54 do
55 {
56 c1 = TOLOWER (*p1);
57 c2 = TOLOWER (*p2);
58
59 if (LENGTH_LIMIT_EXPR (--n == 0) || c1 == '\0')
60 break;
61
62 ++p1;
63 ++p2;
64 }
65 while (c1 == c2);
66
67 return c1 - c2;
68 }
69