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[glibc/history.git] / string / strncase.c
bloba55aaf6a3a9b0d68a3170d3e0322d5603444221e
1 /* Compare at most N characters of two strings without taking care for
2 the case.
3 Copyright (C) 1992, 1996, 1997, 2001, 2004 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library 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 GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
21 #ifdef HAVE_CONFIG_H
22 # include <config.h>
23 #endif
25 #include <string.h>
26 #include <ctype.h>
28 #ifndef weak_alias
29 # define __strncasecmp strncasecmp
30 # define TOLOWER(Ch) tolower (Ch)
31 #else
32 # include <locale/localeinfo.h>
33 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
34 # define __strncasecmp __strncasecmp_l
35 # endif
36 # define TOLOWER(Ch) __tolower_l ((Ch), loc)
37 #endif
39 #ifdef USE_IN_EXTENDED_LOCALE_MODEL
40 # define LOCALE_PARAM , loc
41 # define LOCALE_PARAM_DECL __locale_t loc;
42 #else
43 # define LOCALE_PARAM
44 # define LOCALE_PARAM_DECL
45 #endif
47 /* Compare no more than N characters of S1 and S2,
48 ignoring case, returning less than, equal to or
49 greater than zero if S1 is lexicographically less
50 than, equal to or greater than S2. */
51 int
52 __strncasecmp (s1, s2, n LOCALE_PARAM)
53 const char *s1;
54 const char *s2;
55 size_t n;
56 LOCALE_PARAM_DECL
58 #if defined _LIBC && !defined USE_IN_EXTENDED_LOCALE_MODEL
59 __locale_t loc = _NL_CURRENT_LOCALE;
60 #endif
61 const unsigned char *p1 = (const unsigned char *) s1;
62 const unsigned char *p2 = (const unsigned char *) s2;
63 int result;
65 if (p1 == p2 || n == 0)
66 return 0;
68 while ((result = TOLOWER (*p1) - TOLOWER (*p2++)) == 0)
69 if (*p1++ == '\0' || --n == 0)
70 break;
72 return result;
74 #ifndef __strncasecmp
75 weak_alias (__strncasecmp, strncasecmp)
76 #endif