1/* Return number of characters in multibyte representation for current
2 character set.
3 Copyright (C) 1996-2020 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
6
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
11
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
16
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <https://www.gnu.org/licenses/>. */
20
21#include <langinfo.h>
22#include <locale.h>
23#include <stdlib.h>
24#include "localeinfo.h"
25
26
27/* This is a gross hack to get broken programs running.
28
29 ISO C provides no mean to find out how many bytes the wide
30 character representation really uses. But it defines MB_CUR_LEN to
31 return the information for the multi-byte character representation.
32 Many programmers don't know the difference between the two and
33 think this means the same. But assuming all characters have a size
34 of MB_CUR_LEN after they have been processed by `mbrtowc' is wrong.
35 Instead the maximum number of characters used for the conversion is
36 MB_CUR_LEN.
37
38 It is known that some Motif applications have this problem. To
39 cure this one has to make sure the glibc uses the function in this
40 file instead of the one in locale/mb_cur_max.c. This can either be
41 done by linking with this file or by using the LD_PRELOAD feature
42 of the dynamic linker. */
43size_t
44__ctype_get_mb_cur_max (void)
45{
46 union locale_data_value u;
47
48 u.string = nl_langinfo (_NL_CTYPE_MB_CUR_MAX);
49 return ((size_t []) { 1, 1, 1, 2, 2, 3, 4 })[u.word];
50}
51