[apple/libc.git] / locale / FreeBSD / wcwidth.3

.\" Copyright (c) 2002 Tim J. Robbins
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD: src/lib/libc/locale/wcwidth.3,v 1.6 2004/08/17 04:56:03 trhodes Exp $
.\"
.Dd August 17, 2004
.Dt WCWIDTH 3
.Os
.Sh NAME
.Nm wcwidth
.Nd "number of column positions of a wide-character code"
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In wchar.h
.Ft int
.Fn wcwidth "wchar_t wc"
.Sh DESCRIPTION
The
.Fn wcwidth
function determines the number of column positions required to
display the wide character
.Fa wc .
.Sh RETURN VALUES
The
.Fn wcwidth
function returns 0 if the
.Fa wc
argument is a null wide character (L'\e0'),
\-1 if
.Fa wc
is not printable,
otherwise it returns the number of column positions the
character occupies.
.Sh EXAMPLES
This code fragment reads text from standard input and
breaks lines that are more than 20 column positions wide,
similar to the
.Xr fold 1
utility:
.Bd -literal -offset indent
wint_t ch;
int column, w;

column = 0;
while ((ch = getwchar()) != WEOF) {
	w = wcwidth(ch);
	if (w > 0 && column + w >= 20) {
		putwchar(L'\en');
		column = 0;
	}
	putwchar(ch);
	if (ch == L'\en')
		column = 0;
	else if (w > 0)
		column += w;
}
.Ed
.Sh SEE ALSO
.Xr iswprint 3 ,
.Xr wcswidth 3
.Sh STANDARDS
The
.Fn wcwidth
function conforms to
.St -p1003.1-2001 .
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
9385eb3d A	31	.Nm wcwidth
9385eb3d A	32	.Nd "number of column positions of a wide-character code"
5b2abdfb A	33	.Sh LIBRARY
	34	.Lb libc
	35	.Sh SYNOPSIS
9385eb3d	36	.In wchar.h
5b2abdfb	37	.Ft int
9385eb3d	38	.Fn wcwidth "wchar_t wc"
5b2abdfb	39	.Sh DESCRIPTION
9385eb3d A	40	The
	41	.Fn wcwidth
	42	function determines the number of column positions required to
	43	display the wide character
	44	.Fa wc .
5b2abdfb	45	.Sh RETURN VALUES
9385eb3d A	46	The
	47	.Fn wcwidth
	48	function returns 0 if the
	49	.Fa wc
	50	argument is a null wide character (L'\e0'),
	51	\-1 if
	52	.Fa wc
	53	is not printable,
	54	otherwise it returns the number of column positions the
	55	character occupies.
	56	.Sh EXAMPLES
	57	This code fragment reads text from standard input and
	58	breaks lines that are more than 20 column positions wide,
	59	similar to the
	60	.Xr fold 1
	61	utility:
	62	.Bd -literal -offset indent
	63	wint_t ch;
	64	int column, w;
	65
	66	column = 0;
	67	while ((ch = getwchar()) != WEOF) {
3d9156a7 A	68	w = wcwidth(ch);
3d9156a7 A	69	if (w > 0 && column + w >= 20) {
9385eb3d A	70	putwchar(L'\en');
	71	column = 0;
	72	}
	73	putwchar(ch);
	74	if (ch == L'\en')
	75	column = 0;
3d9156a7 A	76	else if (w > 0)
3d9156a7 A	77	column += w;
9385eb3d A	78	}
9385eb3d A	79	.Ed
5b2abdfb	80	.Sh SEE ALSO
9385eb3d A	81	.Xr iswprint 3 ,
	82	.Xr wcswidth 3
	83	.Sh STANDARDS
5b2abdfb	84	The
9385eb3d A	85	.Fn wcwidth
	86	function conforms to
	87	.St -p1003.1-2001 .