1.\" $NetBSD: wcwidth.3,v 1.3 2006/10/14 07:51:01 wiz Exp $ 2.\" FreeBSD: src/lib/libc/locale/wcwidth.3,v 1.6 2004/08/17 04:56:03 trhodes Exp 3.\" 4.\" Copyright (c) 2002 Tim J. Robbins 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $DragonFly: src/lib/libc/locale/wcwidth.3,v 1.1 2008/05/31 04:51:55 swildner Exp $ 29.\" 30.Dd May 30, 2008 31.Dt WCWIDTH 3 32.Os 33.Sh NAME 34.Nm wcwidth 35.Nd "number of column positions of a wide-character code" 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In wchar.h 40.Ft int 41.Fn wcwidth "wchar_t wc" 42.Sh DESCRIPTION 43The 44.Fn wcwidth 45function determines the number of column positions required to 46display the wide character 47.Fa wc . 48.Sh RETURN VALUES 49The 50.Fn wcwidth 51function returns 0 if the 52.Fa wc 53argument is a nul wide character (L'\e0'), 54\-1 if 55.Fa wc 56is not printable, 57otherwise it returns the number of column positions the 58character occupies. 59.Sh EXAMPLES 60This code fragment reads text from standard input and 61breaks lines that are more than 20 column positions wide, 62similar to the 63.Xr fold 1 64utility: 65.Bd -literal -offset indent 66wint_t ch; 67int column, w; 68 69column = 0; 70while ((ch = getwchar()) != WEOF) { 71 w = wcwidth(ch); 72 if (w \*[Gt] 0 \*[Am]\*[Am] column + w \*[Gt]= 20) { 73 putwchar(L'\en'); 74 column = 0; 75 } 76 putwchar(ch); 77 if (ch == L'\en') 78 column = 0; 79 else if (w \*[Gt] 0) 80 column += w; 81} 82.Ed 83.Sh SEE ALSO 84.Xr iswprint 3 , 85.Xr wcswidth 3 86.Sh STANDARDS 87The 88.Fn wcwidth 89function conforms to 90.St -p1003.1-2001 . 91