(PHP 4, PHP 5)
htmlspecialchars — Convert special characters to HTML entities
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 translations performed are:
The string being converted.
The optional second argument, flags, tells the function what to do with single and double quote characters and with invalid multi-byte sequences. 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. In addition, since 5.3.0, these constants can be combined with ENT_IGNORE. In that case, strings that contain invalid code unit sequences have those invalid sequences discarded instead of having the function return an empty string. Avoid using it, as it may have introduce vulnerabilities.
Defines character set used in conversion. The default character set is ISO-8859-1.
For the purposes of this function, the charsets ISO-8859-1, ISO-8859-15, UTF-8, cp866, cp1251, cp1252, and KOI8-R are effectively equivalent, as the characters affected by htmlspecialchars() occupy the same positions in all of these charsets.
Following character sets are supported in PHP 4.3.0 and later.
| 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 |
Note: Any other character sets are not recognized and ISO-8859-1 will be used instead.
When double_encode is turned off PHP will not encode existing html entities, the default is to convert everything.
The converted string.
| Version | Description |
|---|---|
| 5.2.3 | The double_encode parameter was added. |
| 4.1.0 | The charset parameter was added. |
Example #1 htmlspecialchars() example
<?php
$new = htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES);
echo $new; // <a href='test'>Test</a>
?>
Note:
Note that this function does not translate anything beyond what is listed above. For full entity translation, see htmlentities().