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      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
     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