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Commit	Line	Data
9385eb3d	1	.\" Copyright (c) 2002 Tim J. Robbins
5b2abdfb A	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	.\"
3d9156a7	25	.\" $FreeBSD: src/lib/libc/locale/wcwidth.3,v 1.6 2004/08/17 04:56:03 trhodes Exp $
5b2abdfb	26	.\"
3d9156a7	27	.Dd August 17, 2004
9385eb3d	28	.Dt WCWIDTH 3
5b2abdfb A	29	.Os
5b2abdfb A	30	.Sh NAME
ad3c9f2a A	31	.Nm wcwidth ,
ad3c9f2a A	32	.Nm wcwidth_l
9385eb3d	33	.Nd "number of column positions of a wide-character code"
5b2abdfb A	34	.Sh LIBRARY
	35	.Lb libc
	36	.Sh SYNOPSIS
9385eb3d	37	.In wchar.h
5b2abdfb	38	.Ft int
ad3c9f2a A	39	.Fo wcwidth
	40	.Fa "wchar_t wc"
	41	.Fc
	42	.In wchar.h
	43	.In xlocale.h
	44	.Ft int
	45	.Fo wcwidth_l
	46	.Fa "wchar_t wc"
	47	.Fa "locale_t loc"
	48	.Fc
5b2abdfb	49	.Sh DESCRIPTION
9385eb3d A	50	The
	51	.Fn wcwidth
	52	function determines the number of column positions required to
	53	display the wide character
	54	.Fa wc .
ad3c9f2a A	55	.Pp
	56	Although the
	57	.Fn wcwidth
	58	function uses the current locale, the
	59	.Fn wcwidth_l
	60	function may be passed a locale directly. See
	61	.Xr xlocale 3
	62	for more information.
5b2abdfb	63	.Sh RETURN VALUES
9385eb3d A	64	The
	65	.Fn wcwidth
	66	function returns 0 if the
	67	.Fa wc
	68	argument is a null wide character (L'\e0'),
	69	\-1 if
	70	.Fa wc
ad3c9f2a A	71	is not printable;
ad3c9f2a A	72	otherwise, it returns the number of column positions the
9385eb3d A	73	character occupies.
	74	.Sh EXAMPLES
	75	This code fragment reads text from standard input and
	76	breaks lines that are more than 20 column positions wide,
	77	similar to the
	78	.Xr fold 1
	79	utility:
	80	.Bd -literal -offset indent
	81	wint_t ch;
	82	int column, w;
	83
	84	column = 0;
	85	while ((ch = getwchar()) != WEOF) {
3d9156a7 A	86	w = wcwidth(ch);
3d9156a7 A	87	if (w > 0 && column + w >= 20) {
9385eb3d A	88	putwchar(L'\en');
	89	column = 0;
	90	}
	91	putwchar(ch);
	92	if (ch == L'\en')
	93	column = 0;
3d9156a7 A	94	else if (w > 0)
3d9156a7 A	95	column += w;
9385eb3d A	96	}
9385eb3d A	97	.Ed
5b2abdfb	98	.Sh SEE ALSO
9385eb3d	99	.Xr iswprint 3 ,
ad3c9f2a A	100	.Xr wcswidth 3 ,
ad3c9f2a A	101	.Xr xlocale 3
9385eb3d	102	.Sh STANDARDS
5b2abdfb	103	The
9385eb3d A	104	.Fn wcwidth
	105	function conforms to
	106	.St -p1003.1-2001 .