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.\" 27.Dd August 17, 2004 28.Dt WCWIDTH 3 29.Os 30.Sh NAME 31.Nm wcwidth 32.Nd "number of column positions of a wide-character code" 33.Sh LIBRARY 34.Lb libc 35.Sh SYNOPSIS 36.In wchar.h 37.Ft int 38.Fn wcwidth "wchar_t wc" 39.Sh DESCRIPTION 40The 41.Fn wcwidth 42function determines the number of column positions required to 43display the wide character 44.Fa wc . 45.Sh RETURN VALUES 46The 47.Fn wcwidth 48function returns 0 if the 49.Fa wc 50argument is a null wide character (L'\e0'), 51\-1 if 52.Fa wc 53is not printable, 54otherwise it returns the number of column positions the 55character occupies. 56.Sh EXAMPLES 57This code fragment reads text from standard input and 58breaks lines that are more than 20 column positions wide, 59similar to the 60.Xr fold 1 61utility: 62.Bd -literal -offset indent 63wint_t ch; 64int column, w; 65 66column = 0; 67while ((ch = getwchar()) != WEOF) { 68 w = wcwidth(ch); 69 if (w > 0 && column + w >= 20) { 70 putwchar(L'\en'); 71 column = 0; 72 } 73 putwchar(ch); 74 if (ch == L'\en') 75 column = 0; 76 else if (w > 0) 77 column += w; 78} 79.Ed 80.Sh SEE ALSO 81.Xr iswprint 3 , 82.Xr wcswidth 3 83.Sh STANDARDS 84The 85.Fn wcwidth 86function conforms to 87.St -p1003.1-2001 . 88