Line data Source code
1 : /* c-strncasecmp.c -- case insensitive string comparator in C locale
2 : Copyright (C) 1998-1999, 2005-2006, 2009-2020 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 Lesser General Public License as published by
6 : the Free Software Foundation; either version 2.1, 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 Lesser General Public License for more details.
13 :
14 : You should have received a copy of the GNU Lesser General Public License
15 : along with this program; if not, see <https://www.gnu.org/licenses/>. */
16 :
17 : #include <config.h>
18 :
19 : /* Specification. */
20 : #include "c-strcase.h"
21 :
22 : #include <limits.h>
23 :
24 : #include "c-ctype.h"
25 :
26 : int
27 42151 : c_strncasecmp (const char *s1, const char *s2, size_t n)
28 : {
29 42151 : register const unsigned char *p1 = (const unsigned char *) s1;
30 42151 : register const unsigned char *p2 = (const unsigned char *) s2;
31 : unsigned char c1, c2;
32 :
33 42151 : if (p1 == p2 || n == 0)
34 0 : return 0;
35 :
36 : do
37 : {
38 109823 : c1 = c_tolower (*p1);
39 109823 : c2 = c_tolower (*p2);
40 :
41 109823 : if (--n == 0 || c1 == '\0')
42 : break;
43 :
44 73983 : ++p1;
45 73983 : ++p2;
46 : }
47 73983 : while (c1 == c2);
48 :
49 : if (UCHAR_MAX <= INT_MAX)
50 42151 : return c1 - c2;
51 : else
52 : /* On machines where 'char' and 'int' are types of the same size, the
53 : difference of two 'unsigned char' values - including the sign bit -
54 : doesn't fit in an 'int'. */
55 : return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
56 : }
|