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.Dd August 17, 2004 26.Dt WCWIDTH 3 27.Os 28.Sh NAME 29.Nm wcwidth 30.Nd "number of column positions of a wide-character code" 31.Sh LIBRARY 32.Lb libc 33.Sh SYNOPSIS 34.In wchar.h 35.Ft int 36.Fn wcwidth "wchar_t wc" 37.Sh DESCRIPTION 38The 39.Fn wcwidth 40function determines the number of column positions required to 41display the wide character 42.Fa wc . 43.Sh RETURN VALUES 44The 45.Fn wcwidth 46function returns 0 if the 47.Fa wc 48argument is a null wide character (L'\e0'), 49\-1 if 50.Fa wc 51is not printable, 52otherwise it returns the number of column positions the 53character occupies. 54.Sh EXAMPLES 55This code fragment reads text from standard input and 56breaks lines that are more than 20 column positions wide, 57similar to the 58.Xr fold 1 59utility: 60.Bd -literal -offset indent 61wint_t ch; 62int column, w; 63 64column = 0; 65while ((ch = getwchar()) != WEOF) { 66 w = wcwidth(ch); 67 if (w > 0 && column + w >= 20) { 68 putwchar(L'\en'); 69 column = 0; 70 } 71 putwchar(ch); 72 if (ch == L'\en') 73 column = 0; 74 else if (w > 0) 75 column += w; 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