(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:
- '&' (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 '>'
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, provided the string itself is valid for the character set, 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.
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 '' An empty string activates detection from script encoding (Zend multibyte), default_charset and current locale (see nl_langinfo() and setlocale()), in this order. Not recommended.
Note: Any other character sets are not recognized. The default encoding will be used instead and a warning will be emitted.
When double_encode is turned off PHP will not encode existing html entities, the default is to convert everything.
The converted string.
If the input string contains an invalid code unit sequence within the given charset and the ENT_IGNORE flag is not set, then htmlspecialchars() will return an empty string.
|5.2.3||The double_encode parameter was added.|
|4.1.0||The charset parameter was added.|
Example #1 htmlspecialchars() example
$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().
- get_html_translation_table() - Returns the translation table used by htmlspecialchars and htmlentities
- htmlspecialchars_decode() - Convert special HTML entities back to characters
- strip_tags() - Strip HTML and PHP tags from a string
- htmlentities() - Convert all applicable characters to HTML entities
- nl2br() - Inserts HTML line breaks before all newlines in a string