|
421
|
1 /* strncasecmp.c -- case insensitive string comparator
|
|
|
2 Copyright (C) 1998-1999, 2005-2007, 2009-2010 Free Software Foundation, Inc.
|
|
|
3
|
|
|
4 This program is free software; you can redistribute it and/or modify
|
|
|
5 it under the terms of the GNU General Public License as published by
|
|
|
6 the Free Software Foundation; either version 3, or (at your option)
|
|
|
7 any later version.
|
|
|
8
|
|
|
9 This program is distributed in the hope that it will be useful,
|
|
|
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
12 GNU General Public License for more details.
|
|
|
13
|
|
|
14 You should have received a copy of the GNU General Public License
|
|
|
15 along with this program; if not, write to the Free Software Foundation,
|
|
|
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
|
|
|
17
|
|
|
18 #include <config.h>
|
|
|
19
|
|
|
20 /* Specification. */
|
|
|
21 #include <string.h>
|
|
|
22
|
|
|
23 #include <ctype.h>
|
|
|
24 #include <limits.h>
|
|
|
25
|
|
|
26 #define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
|
|
|
27
|
|
|
28 /* Compare no more than N bytes of strings S1 and S2, ignoring case,
|
|
|
29 returning less than, equal to or greater than zero if S1 is
|
|
|
30 lexicographically less than, equal to or greater than S2.
|
|
|
31 Note: This function cannot work correctly in multibyte locales. */
|
|
|
32
|
|
|
33 int
|
|
|
34 strncasecmp (const char *s1, const char *s2, size_t n)
|
|
|
35 {
|
|
|
36 register const unsigned char *p1 = (const unsigned char *) s1;
|
|
|
37 register const unsigned char *p2 = (const unsigned char *) s2;
|
|
|
38 unsigned char c1, c2;
|
|
|
39
|
|
|
40 if (p1 == p2 || n == 0)
|
|
|
41 return 0;
|
|
|
42
|
|
|
43 do
|
|
|
44 {
|
|
|
45 c1 = TOLOWER (*p1);
|
|
|
46 c2 = TOLOWER (*p2);
|
|
|
47
|
|
|
48 if (--n == 0 || c1 == '\0')
|
|
|
49 break;
|
|
|
50
|
|
|
51 ++p1;
|
|
|
52 ++p2;
|
|
|
53 }
|
|
|
54 while (c1 == c2);
|
|
|
55
|
|
|
56 if (UCHAR_MAX <= INT_MAX)
|
|
|
57 return c1 - c2;
|
|
|
58 else
|
|
|
59 /* On machines where 'char' and 'int' are types of the same size, the
|
|
|
60 difference of two 'unsigned char' values - including the sign bit -
|
|
|
61 doesn't fit in an 'int'. */
|
|
|
62 return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
|
|
|
63 }
|
