HTMLSPECIALCHARS(3) 1 HTMLSPECIALCHARS(3)
htmlspecialchars - Convert special characters to HTML entities
SYNOPSIS
string htmlspecialchars (string $string, [int $flags = ENT_COMPAT | ENT_HTML401], [string $encoding = ini_get("default_charset")], [bool
$double_encode = true])
DESCRIPTION
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 these conversions made. If you require all input substrings that have associated named entities to be
translated, use htmlentities(3) instead.
If the input string passed to this function and the final document share the same character set, this function is sufficient to prepare
input for inclusion in most contexts of an HTML document. If, however, the input can represent characters that are not coded in the final
document character set and you wish to retain those characters (as numeric or named entities), both this function and htmlentities(3)
(which only encodes substrings that have named entity equivalents) may be insufficient. You may have to use mb_encode_numericentity(3)
instead.
The translations performed are:
o '&' (ampersand) becomes '&'
o '"' (double quote) becomes '"' when
ENT_NOQUOTES is not set.
o "'" (single quote) becomes ''' (or ') only when
ENT_QUOTES is set.
o '<' (less than) becomes '<'
o '>' (greater than) becomes '>'
PARAMETERS
o $string
- The string being converted.
o $flags
- A bitmask of one or more of the following flags, which specify how to handle quotes, invalid code unit sequences and the used
document type. The default is ENT_COMPAT | ENT_HTML401.
Available $flags constants
+---------------+---------------------------------------------------+
|Constant Name | |
| | |
| | Description |
| | |
+---------------+---------------------------------------------------+
| | |
| ENT_COMPAT | |
| | |
| | Will convert double-quotes and leave single- |
| | quotes alone. |
| | |
| | |
| ENT_QUOTES | |
| | |
| | Will convert both double and single quotes. |
| | |
| | |
| ENT_NOQUOTES | |
| | |
| | Will leave both double and single quotes uncon- |
| | verted. |
| | |
| | |
| ENT_IGNORE | |
| | |
| | Silently discard invalid code unit sequences |
| | instead of returning an empty string. Using this |
| | flag is discouraged as it may have security |
| | implications. |
| | |
| | |
|ENT_SUBSTITUTE | |
| | |
| | Replace invalid code unit sequences with a Uni- |
| | code Replacement Character U+FFFD (UTF-8) or |
| | &#FFFD; (otherwise) instead of returning an empty |
| | string. |
| | |
| | |
|ENT_DISALLOWED | |
| | |
| | Replace invalid code points for the given docu- |
| | ment type with a Unicode Replacement Character |
| | U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of |
| | leaving them as is. This may be useful, for |
| | instance, to ensure the well-formedness of XML |
| | documents with embedded external content. |
| | |
| | |
| ENT_HTML401 | |
| | |
| | Handle code as HTML 4.01. |
| | |
| | |
| ENT_XML1 | |
| | |
| | Handle code as XML 1. |
| | |
| | |
| ENT_XHTML | |
| | |
| | Handle code as XHTML. |
| | |
| | |
| ENT_HTML5 | |
| | |
| | Handle code as HTML 5. |
| | |
+---------------+---------------------------------------------------+
o $encoding
- An optional argument defining the encoding used when converting characters. If omitted, the default value of the $encoding
varies depending on the PHP version in use. In PHP 5.6 and later, the default_charset configuration option is used as the default
value. PHP 5.4 and 5.5 will use UTF-8 as the default. Earlier versions of PHP use ISO-8859-1. Although this argument is techni-
cally optional, you are highly encouraged to specify the correct value for your code if you are using PHP 5.5 or earlier, or if
your default_charset configuration option may be set incorrectly for the given input. For the purposes of this function, the
encodings 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 encoding, as the characters affected by htmlspecialchars(3) occupy the same positions in all of these
encodings. The following character sets are supported:
Supported charsets
+------------+--------------------------------------+---+
| Charset | | |
| | | |
| | Aliases | |
| | | |
| | Description | |
| | | |
+------------+--------------------------------------+---+
|ISO-8859-1 | | |
| | | |
| | ISO8859-1 | |
| | | |
| | Western European, Latin-1. | |
| | | |
|ISO-8859-5 | | |
| | | |
| | ISO8859-5 | |
| | | |
| | Little used cyrillic charset | |
| | (Latin/Cyrillic). | |
| | | |
|ISO-8859-15 | | |
| | | |
| | ISO8859-15 | |
| | | |
| | Western European, Latin-9. Adds the | |
| | Euro sign, French and Finnish let- | |
| | ters missing in Latin-1 | |
| | (ISO-8859-1). | |
| | | |
| UTF-8 | | |
| | | |
| | | |
| | |T{ | |
| | ASCII compatible multi-byte 8-bit | |
| | Unicode. | |
| | | |
| cp866 | | |
| | | |
| | ibm866, 866 | |
| | | |
| | DOS-specific Cyrillic charset. | |
| | | |
| cp1251 | | |
| | | |
| | Windows-1251, win-1251, 1251 | |
| | | |
| | Windows-specific Cyrillic charset. | |
| | | |
| cp1252 | | |
| | | |
| | Windows-1252, 1252 | |
| | | |
| | Windows specific charset for West- | |
| | ern European. | |
| | | |
| KOI8-R | | |
| | | |
| | koi8-ru, koi8r | |
| | | |
| | Russian. | |
| | | |
| BIG5 | | |
| | | |
| | 950 | |
| | | |
| | Traditional Chinese, mainly used in | |
| | Taiwan. | |
| | | |
| GB2312 | | |
| | | |
| | 936 | |
| | | |
| | Simplified Chinese, national stan- | |
| | dard character set. | |
| | | |
|BIG5-HKSCS | | |
| | | |
| | | |
| | |T{ | |
| | Big5 with Hong Kong extensions, | |
| | Traditional Chinese. | |
| | | |
| Shift_JIS | | |
| | | |
| | SJIS, SJIS-win, cp932, 932 | |
| | | |
| | Japanese | |
| | | |
| EUC-JP | | |
| | | |
| | EUCJP, eucJP-win | |
| | | |
| | Japanese | |
| | | |
| MacRoman | | |
| | | |
| | | |
| | |T{ | |
| | Charset that was used by Mac OS. | |
| | | |
| | | |
| '' | | |
| | | |
| | | |
| | |T{ | |
| | An empty string activates detection | |
| | from script encoding (Zend multi- | |
| | byte), default_charset and current | |
| | locale (see nl_langinfo(3) and set- | |
| | locale(3)), in this order. Not rec- | |
| | ommended. | |
| | | |
+------------+--------------------------------------+---+
Note
Any other character sets are not recognized. The default encoding will be used instead and a warning will be emitted.
o $double_encode
- When $double_encode is turned off PHP will not encode existing html entities, the default is to convert everything.
RETURN VALUES
The converted string.
If the input $string contains an invalid code unit sequence within the given $encoding an empty string will be returned, unless either the
ENT_IGNORE or ENT_SUBSTITUTE flags are set.
CHANGELOG
+--------+---------------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------------------------+
| 5.6.0 | |
| | |
| | The default value for the $encoding parameter |
| | was changed to be the value of the |
| | default_charset configuration option. |
| | |
| 5.4.0 | |
| | |
| | The default value for the $encoding parameter |
| | was changed to UTF-8. |
| | |
| 5.4.0 | |
| | |
| | The constants ENT_SUBSTITUTE, ENT_DISALLOWED, |
| | ENT_HTML401, ENT_XML1, ENT_XHTML and ENT_HTML5 |
| | were added. |
| | |
| 5.3.0 | |
| | |
| | The constant ENT_IGNORE was added. |
| | |
| 5.2.3 | |
| | |
| | The $double_encode parameter was added. |
| | |
+--------+---------------------------------------------------+
EXAMPLES
Example #1
htmlspecialchars(3) example
<?php
$new = htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES);
echo $new; // <a href='test'>Test</a>
?>
NOTES
Note
Note that this function does not translate anything beyond what is listed above. For full entity translation, see htmlentities(3).
SEE ALSO
get_html_translation_table(3), htmlspecialchars_decode(3), strip_tags(3), htmlentities(3), nl2br(3).
PHP Documentation Group HTMLSPECIALCHARS(3)