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