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.\" 29.Dd August 17, 2004 30.Dt WCWIDTH 3 31.Os 32.Sh NAME 33.Nm wcwidth 34.Nd "number of column positions of a wide-character code" 35.Sh LIBRARY 36.Lb libc 37.Sh SYNOPSIS 38.In wchar.h 39.Ft int 40.Fn wcwidth "wchar_t wc" 41.Sh DESCRIPTION 42The 43.Fn wcwidth 44function determines the number of column positions required to 45display the wide character 46.Fa wc . 47.Sh RETURN VALUES 48The 49.Fn wcwidth 50function returns 0 if the 51.Fa wc 52argument is a nul wide character (L'\e0'), 53\-1 if 54.Fa wc 55is not printable, 56otherwise it returns the number of column positions the 57character occupies. 58.Sh EXAMPLES 59This code fragment reads text from standard input and 60breaks lines that are more than 20 column positions wide, 61similar to the 62.Xr fold 1 63utility: 64.Bd -literal -offset indent 65wint_t ch; 66int column, w; 67 68column = 0; 69while ((ch = getwchar()) != WEOF) { 70 w = wcwidth(ch); 71 if (w \*[Gt] 0 \*[Am]\*[Am] column + w \*[Gt]= 20) { 72 putwchar(L'\en'); 73 column = 0; 74 } 75 putwchar(ch); 76 if (ch == L'\en') 77 column = 0; 78 else if (w \*[Gt] 0) 79 column += w; 80} 81.Ed 82.Sh SEE ALSO 83.Xr iswprint 3 , 84.Xr wcswidth 3 85.Sh STANDARDS 86The 87.Fn wcwidth 88function conforms to 89.St -p1003.1-2001 . 90