1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html401/loose.dtd">
<html>
<!-- Created on February, 23 2026 by texi2html 1.78a -->
<!--
Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author)
Karl Berry <karl@freefriends.org>
Olaf Bachmann <obachman@mathematik.uni-kl.de>
and many others.
Maintained by: Many creative people.
Send bugs and suggestions to <texi2html-bug@nongnu.org>
-->
<head>
<title>GNU libunistring: 9. Display width <uniwidth.h></title>
<meta name="description" content="GNU libunistring: 9. Display width <uniwidth.h>">
<meta name="keywords" content="GNU libunistring: 9. Display width <uniwidth.h>">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="texi2html 1.78a">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
pre.display {font-family: serif}
pre.format {font-family: serif}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: serif; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: serif; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.roman {font-family:serif; font-weight:normal;}
span.sansserif {font-family:sans-serif; font-weight:normal;}
ul.toc {list-style: none}
-->
</style>
</head>
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="libunistring_8.html#SEC33" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="libunistring_10.html#SEC56" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="libunistring_toc.html#SEC_Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="libunistring_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="libunistring_21.html#SEC94" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="libunistring_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<hr size="2">
<a name="uniwidth_002eh"></a>
<a name="SEC55"></a>
<h1 class="chapter"> <a href="libunistring_toc.html#TOC55">9. Display width <code><uniwidth.h></code></a> </h1>
<p>This include file declares functions that return the display width, measured
in columns, of characters or strings, when output to a device that uses
non-proportional fonts.
</p>
<a name="IDX780"></a>
<p>Note that for some rarely used characters the actual fonts or terminal
emulators can use a different width. There is no mechanism for communicating
the display width of characters across a Unix pseudo-terminal (tty). Also,
there are scripts with complex rendering, like the Indic scripts. For these
scripts, there is no such concept as non-proportional fonts. Therefore
the results of these functions usually work fine on most scripts and on
most characters but can fail to represent the actual display width.
</p>
<p>These functions are locale dependent. The <var>encoding</var> argument identifies
the encoding (e.g. <code>"ISO-8859-2"</code> for Polish).
</p>
<a name="IDX781"></a>
<a name="IDX782"></a>
<a name="IDX783"></a>
<dl>
<dt><u>Function:</u> int <b>uc_width</b><i> (ucs4_t <var>uc</var>, const char *<var>encoding</var>)</i>
<a name="IDX784"></a>
</dt>
<dd><p>Determines and returns the number of column positions required for <var>uc</var>.
Returns -1 if <var>uc</var> is a control character that has an influence on the
column position when output.
</p></dd></dl>
<dl>
<dt><u>Function:</u> int <b>u8_width</b><i> (const uint8_t *<var>s</var>, size_t <var>n</var>, const char *<var>encoding</var>)</i>
<a name="IDX785"></a>
</dt>
<dt><u>Function:</u> int <b>u16_width</b><i> (const uint16_t *<var>s</var>, size_t <var>n</var>, const char *<var>encoding</var>)</i>
<a name="IDX786"></a>
</dt>
<dt><u>Function:</u> int <b>u32_width</b><i> (const uint32_t *<var>s</var>, size_t <var>n</var>, const char *<var>encoding</var>)</i>
<a name="IDX787"></a>
</dt>
<dd><p>Determines and returns the number of column positions required for first
<var>n</var> units (or fewer if <var>s</var> ends before this) in <var>s</var>. This
function ignores control characters in the string.
</p></dd></dl>
<dl>
<dt><u>Function:</u> int <b>u8_strwidth</b><i> (const uint8_t *<var>s</var>, const char *<var>encoding</var>)</i>
<a name="IDX788"></a>
</dt>
<dt><u>Function:</u> int <b>u16_strwidth</b><i> (const uint16_t *<var>s</var>, const char *<var>encoding</var>)</i>
<a name="IDX789"></a>
</dt>
<dt><u>Function:</u> int <b>u32_strwidth</b><i> (const uint32_t *<var>s</var>, const char *<var>encoding</var>)</i>
<a name="IDX790"></a>
</dt>
<dd><p>Determines and returns the number of column positions required for <var>s</var>.
This function ignores control characters in the string.
</p></dd></dl>
<hr size="6">
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="libunistring_8.html#SEC33" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="libunistring_10.html#SEC56" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="libunistring_toc.html#SEC_Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="libunistring_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="libunistring_21.html#SEC94" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="libunistring_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<p>
<font size="-1">
This document was generated by <em>Bruno Haible</em> on <em>February, 23 2026</em> using <a href="https://www.nongnu.org/texi2html/"><em>texi2html 1.78a</em></a>.
</font>
<br>
</p>
</body>
</html>
|
