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: head/lib/libc/locale/wcwidth.3 133915 2004-08-17 04:56:03Z trhodes $ 26.\" 27.Dd December 27, 2013 28.Dt WCWIDTH 3 29.Os 30.Sh NAME 31.Nm wcwidth , 32.Nm wcwidth_l 33.Nd "number of column positions of a wide-character code" 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In wchar.h 38.Ft int 39.Fn wcwidth "wchar_t wc" 40.In xlocale.h 41.Ft int 42.Fn wcwidth_l "wchar_t wc" "locale_t locale" 43.Sh DESCRIPTION 44The 45.Fn wcwidth 46and 47.Fn wcwidth_l 48functions determine the number of column positions required to 49display the wide character 50.Fa wc . 51.Pp 52The 53.Fn wcwidth_l 54function takes an explicit 55.Fa locale 56argument, whereas the 57.Fn wcwidth 58function uses the current global or per-thread locale. 59.Sh RETURN VALUES 60The 61.Fn wcwidth 62and 63.Fn wcwidth_l 64functions return 0 if the 65.Fa wc 66argument is a null wide character (L'\e0'), 67\-1 if 68.Fa wc 69is not printable, 70otherwise they return the number of column positions the 71character occupies. 72.Sh EXAMPLES 73This code fragment reads text from standard input and 74breaks lines that are more than 20 column positions wide, 75similar to the 76.Xr fold 1 77utility: 78.Bd -literal -offset indent 79wint_t ch; 80int column, w; 81 82column = 0; 83while ((ch = getwchar()) != WEOF) { 84 w = wcwidth(ch); 85 if (w > 0 && column + w >= 20) { 86 putwchar(L'\en'); 87 column = 0; 88 } 89 putwchar(ch); 90 if (ch == L'\en') 91 column = 0; 92 else if (w > 0) 93 column += w; 94} 95.Ed 96.Sh SEE ALSO 97.Xr iswprint 3 , 98.Xr wcswidth 3 , 99.Xr xlocale 3 100.Sh STANDARDS 101The 102.Fn wcwidth 103function conforms to 104.St -p1003.1-2001 . 105