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
142
143
144
|
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.2 $ -->
<chapter xml:id="mbstring.overload" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
<title>
Function Overloading Feature
</title>
<para>
You might often find it difficult to get an existing PHP application
to work in a given multibyte environment. This happens because most
PHP applications out there are written with the standard string
functions such as <function>substr</function>, which are known to
not properly handle multibyte-encoded strings.
</para>
<para>
mbstring supports a 'function overloading' feature which enables
you to add multibyte awareness to such an application without
code modification by overloading multibyte counterparts on
the standard string functions. For example,
<function>mb_substr</function> is called instead of
<function>substr</function> if function overloading is enabled.
This feature makes it easy to port applications that only support
single-byte encodings to a multibyte environment in many cases.
</para>
<para>
To use function overloading, set
<literal>mbstring.func_overload</literal> in &php.ini; to a
positive value that represents a combination of bitmasks specifying
the categories of functions to be overloaded. It should be set
to 1 to overload the <function>mail</function> function. 2 for string
functions, 4 for regular expression functions. For example,
if it is set to 7, mail, strings and regular expression functions will
be overloaded. The list of overloaded functions are shown below.
<table>
<title>Functions to be overloaded</title>
<tgroup cols="3">
<thead>
<row>
<entry>value of mbstring.func_overload</entry>
<entry>original function</entry>
<entry>overloaded function</entry>
</row>
</thead>
<tbody>
<row>
<entry>1</entry>
<entry><function>mail</function></entry>
<entry><function>mb_send_mail</function></entry>
</row>
<row>
<entry>2</entry>
<entry><function>strlen</function></entry>
<entry><function>mb_strlen</function></entry>
</row>
<row>
<entry>2</entry>
<entry><function>strpos</function></entry>
<entry><function>mb_strpos</function></entry>
</row>
<row>
<entry>2</entry>
<entry><function>strrpos</function></entry>
<entry><function>mb_strrpos</function></entry>
</row>
<row>
<entry>2</entry>
<entry><function>substr</function></entry>
<entry><function>mb_substr</function></entry>
</row>
<row>
<entry>2</entry>
<entry><function>strtolower</function></entry>
<entry><function>mb_strtolower</function></entry>
</row>
<row>
<entry>2</entry>
<entry><function>strtoupper</function></entry>
<entry><function>mb_strtoupper</function></entry>
</row>
<row>
<entry>2</entry>
<entry><function>substr_count</function></entry>
<entry><function>mb_substr_count</function></entry>
</row>
<row>
<entry>4</entry>
<entry><function>ereg</function></entry>
<entry><function>mb_ereg</function></entry>
</row>
<row>
<entry>4</entry>
<entry><function>eregi</function></entry>
<entry><function>mb_eregi</function></entry>
</row>
<row>
<entry>4</entry>
<entry><function>ereg_replace</function></entry>
<entry><function>mb_ereg_replace</function></entry>
</row>
<row>
<entry>4</entry>
<entry><function>eregi_replace</function></entry>
<entry><function>mb_eregi_replace</function></entry>
</row>
<row>
<entry>4</entry>
<entry><function>split</function></entry>
<entry><function>mb_split</function></entry>
</row>
</tbody>
</tgroup>
</table>
</para>
<note>
<para>
It is not recommended to use the function overloading option in
the per-directory context, because it's not confirmed yet to be
stable enough in a production environment and may lead to undefined
behaviour.
</para>
</note>
</chapter>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"../../../manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
|
