man3/wcwidth.3

   1 .\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
   2 .\"
   3 .\" This is free documentation; you can redistribute it and/or
   4 .\" modify it under the terms of the GNU General Public License as
   5 .\" published by the Free Software Foundation; either version 2 of
   6 .\" the License, or (at your option) any later version.
   7 .\"
   8 .\" References consulted:
   9 .\"   GNU glibc-2 source code and manual
  10 .\"   Dinkumware C library reference http://www.dinkumware.com/
  11 .\"   OpenGroup's Single Unix specification http://www.UNIX-systems.org/online.html
  12 .\"
  13 .TH WCWIDTH 3  1999-07-25 "GNU" "Linux Programmer's Manual"
  14 .SH NAME
  15 wcwidth \- determine columns needed for a wide character
  16 .SH SYNOPSIS
  17 .nf
  18 .B #define _XOPEN_SOURCE
  19 .B #include <wchar.h>
  20 .sp
  21 .BI "int wcwidth(wchar_t " c );
  22 .fi
  23 .SH DESCRIPTION
  24 The \fBwcwidth\fP() function returns the number of columns
  25 needed to represent the wide character \fIc\fP.
  26 If \fIc\fP is a printable wide character, the value
  27 is at least 0.
  28 If \fIc\fP is L'\\0', the value is 0. Otherwise \-1 is returned.
  29 .SH "RETURN VALUE"
  30 The \fBwcwidth\fP() function returns the number of
  31 column positions for \fIc\fP.
  32 .SH "CONFORMING TO"
  33 POSIX.1-2001.
  34
  35 Note that glibc before 2.2.5 used the prototype
  36 .br
  37 .nf
  38 .BI "int wcwidth(wint_t " c );
  39 .fi
  40 .SH NOTES
  41 The behaviour of \fBwcwidth\fP() depends on the LC_CTYPE category of the
  42 current locale.
  43 .SH "SEE ALSO"
  44 .BR iswprint (3),
  45 .BR wcswidth (3),
  46 .BR feature_test_macros (7)