man3/wcwidth.3

   1 .\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
   2 .\"
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   4 .\" modify it under the terms of the GNU General Public License as
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   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  2011-09-28 "GNU" "Linux Programmer's Manual"
  14 .SH NAME
  15 wcwidth \- determine columns needed for a wide character
  16 .SH SYNOPSIS
  17 .nf
  18 .BR "#define _XOPEN_SOURCE" "       /* See feature_test_macros(7) */"
  19 .B #include <wchar.h>
  20 .sp
  21 .BI "int wcwidth(wchar_t " c );
  22 .fi
  23 .SH DESCRIPTION
  24 The
  25 .BR wcwidth ()
  26 function returns the number of columns
  27 needed to represent the wide character \fIc\fP.
  28 If \fIc\fP is a printable wide character, the value
  29 is at least 0.
  30 If \fIc\fP is null wide character (L\(aq\\0\(aq), the value is 0.
  31 Otherwise \-1 is returned.
  32 .SH RETURN VALUE
  33 The
  34 .BR wcwidth ()
  35 function returns the number of
  36 column positions for \fIc\fP.
  37 .SH CONFORMING TO
  38 POSIX.1-2001.
  39
  40 Note that glibc before 2.2.5 used the prototype
  41 .br
  42 .nf
  43 .BI "int wcwidth(wint_t " c );
  44 .fi
  45 .SH NOTES
  46 The behavior of
  47 .BR wcwidth ()
  48 depends on the
  49 .B LC_CTYPE
  50 category of the
  51 current locale.
  52 .SH SEE ALSO
  53 .BR iswprint (3),
  54 .BR wcswidth (3)