1 /* Determine the number of screen columns needed for a character.
2 Copyright (C) 2006-2007, 2010-2012 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 of the License, or
7 (at your option) 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, see <http://www.gnu.org/licenses/>. */
16
17 #include <config.h>
18
19 /* Specification. */
20 #include <wchar.h>
21
22 /* Get iswprint. */
23 #include <wctype.h>
24
25 #include "localcharset.h"
26 #include "streq.h"
27 #include "uniwidth.h"
28
29 int
wcwidth(wchar_t wc)30 wcwidth (wchar_t wc)
31 #undef wcwidth
32 {
33 /* In UTF-8 locales, use a Unicode aware width function. */
34 const char *encoding = locale_charset ();
35 if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0 ,0))
36 {
37 /* We assume that in a UTF-8 locale, a wide character is the same as a
38 Unicode character. */
39 return uc_width (wc, encoding);
40 }
41 else
42 {
43 /* Otherwise, fall back to the system's wcwidth function. */
44 #if HAVE_WCWIDTH
45 return wcwidth (wc);
46 #else
47 return wc == 0 ? 0 : iswprint (wc) ? 1 : -1;
48 #endif
49 }
50 }
51