xchange

实际上htmlspecialchars()函数就干了同样的事情。以下摘自PHP手册：
htmlspecialchars
(PHP 3, PHP 4 )

htmlspecialchars --  Convert special characters to HTML entities
Description
string htmlspecialchars ( string string [, int quote_style [, string charset]])


Certain characters have special significance in HTML, and should be represented by HTML entities if they are to preserve their meanings. This function returns a string with some of these conversions made; the translations made are those most useful for everyday web programming. If you require all HTML character entities to be translated, use htmlentities() instead.

This function is useful in preventing user-supplied text from containing HTML markup, such as in a message board or guest book application. The optional second argument, quote_style, tells the function what to do with single and double quote characters. The default mode, ENT_COMPAT, is the backwards compatible mode which only translates the double-quote character and leaves the single-quote untranslated. If ENT_QUOTES is set, both single and double quotes are translated and if ENT_NOQUOTES is set neither single nor double quotes are translated.

The translations performed are:


'&' (ampersand) becomes '&'

'"' (double quote) becomes '"' when ENT_NOQUOTES is not set.

''' (single quote) becomes ''' only when ENT_QUOTES is set.

'<' (less than) becomes '<'

'>' (greater than) becomes '>'

例子 1. htmlspecialchars() example

<?php
$new = htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES);
echo $new; // <a href='test'>Test</a>
?>  



Note that this function does not translate anything beyond what is listed above. For full entity translation, see htmlentities(). Support for the optional second argument was added in PHP 3.0.17 and PHP 4.0.3.

The third argument charset defines character set used in conversion. The default character set is ISO-8859-1. Support for this third argument was added in PHP 4.1.0.

Following character sets are supported in PHP 4.3.0 and later.

表格 1. Supported charsets

Charset Aliases Description
ISO-8859-1 ISO8859-1 Western European, Latin-1  
ISO-8859-15 ISO8859-15 Western European, Latin-9. Adds the Euro sign, French and Finnish letters missing in Latin-1(ISO-8859-1).  
UTF-8   ASCII compatible multi-byte 8-bit Unicode.  
cp866 ibm866, 866 DOS-specific Cyrillic charset. This charset is supported in 4.3.2.  
cp1251 Windows-1251, win-1251, 1251 Windows-specific Cyrillic charset. This charset is supported in 4.3.2.  
cp1252 Windows-1252, 1252 Windows specific charset for Western European.  
KOI8-R koi8-ru, koi8r Russian. This charset is supported in 4.3.2.  
BIG5 950 Traditional Chinese, mainly used in Taiwan.  
GB2312 936 Simplified Chinese, national standard character set.  
BIG5-HKSCS   Big5 with Hong Kong extensions, Traditional Chinese.  
Shift_JIS SJIS, 932 Japanese  
EUC-JP EUCJP Japanese  

注: Any other character sets are not recognized and ISO-8859-1 will be used instead.

小人物大英雄

五个在XML文档中预定义好的实体:

< < 小于号
> > 大于号
& & 和
' ' 单引号
" " 双引号

实体必须以符号"&"开头，以符号";"结尾

我开始还以为'不允许使用呢~所以自定义的函数~