htmlentities
The example for "htmlspecialchars_decode()" below sadly does not work for all PHP4 versions.
Quote from the PHP manual:
"get_html_translation_table() will return the translation table that is used internally for htmlspecialchars() and htmlentities()."
But it does NOT! At least not for PHP version 4.4.2.
This was already reported in a bug report (http://bugs.php.net/bug.php?id=25927), but it was marked as BOGUS.
Proof:
Code:
--------------------
<?php
var_dump(get_html_translation_table(HTML_SPECIALCHARS,ENT_QUOTES));
var_dump(htmlspecialchars('\'',ENT_QUOTES));
?>
--------------------
Output:
--------------------
array
'"' => '"'
''' => '''
'<' => '<'
'>' => '>'
'&' => '&'
'''
--------------------
This comment now is not to report this bug again (though I really believe it is one), but to complete the example and warn people of this pitfall.
To make sure your htmlspecialchars_decode fake for PHP4 works, you should do something like this:
<?php
function htmlspecialchars_decode($string,$style=ENT_COMPAT)
{
$translation = array_flip(get_html_translation_table(HTML_SPECIALCHARS,$style));
if($style === ENT_QUOTES){ $translation['''] = '\''; }
return strtr($string,$translation);
}
?>
Br, Thomas
htmlspecialchars_decode
(PHP 5 >= 5.1.0)
htmlspecialchars_decode — Convert special HTML entities back to characters
Description
string htmlspecialchars_decode
( string
$string
[, int $flags = ENT_COMPAT | ENT_HTML401
] )This function is the opposite of htmlspecialchars(). It converts special HTML entities back to characters.
The converted entities are: &,
" (when ENT_NOQUOTES is not set),
' (when ENT_QUOTES is set),
< and >.
Parameters
-
string -
The string to decode.
-
flags -
A bitmask of one or more of the following flags, which specify how to handle quotes and which document type to use. The default is ENT_COMPAT | ENT_HTML401.
Available flagsconstantsConstant Name Description ENT_COMPATWill convert double-quotes and leave single-quotes alone. ENT_QUOTESWill convert both double and single quotes. ENT_NOQUOTESWill leave both double and single quotes unconverted. ENT_HTML401Handle code as HTML 4.01. ENT_XML1Handle code as XML 1. ENT_XHTMLHandle code as XHTML. ENT_HTML5Handle code as HTML 5.
Return Values
Returns the decoded string.
Changelog
| Version | Description |
|---|---|
| 5.4.0 |
The constants ENT_HTML401, ENT_XML1,
ENT_XHTML and ENT_HTML5 were added.
|
Examples
Example #1 A htmlspecialchars_decode() example
<?php
$str = "<p>this -> "</p>\n";
echo htmlspecialchars_decode($str);
// note that here the quotes aren't converted
echo htmlspecialchars_decode($str, ENT_NOQUOTES);
?>
The above example will output:
<p>this -> "</p> <p>this -> "</p>
See Also
- htmlspecialchars() - Convert special characters to HTML entities
- html_entity_decode() - Convert all HTML entities to their applicable characters
- get_html_translation_table() - Returns the translation table used by htmlspecialchars and htmlentities
add a note
User Contributed Notes
htmlspecialchars_decode - [12 notes]
thomas at xci[ignore_this]teit dot commm ¶
5 years ago
benharold at mac dot com ¶
4 years ago
or of course:
<?php
$var = "Blue & yellow make green.";
$var = (htmlspecialchars_decode($var) == $var) ? htmlspecialchars($var) : $var;
echo $var; // outputs Blue & yellow make green.
// you can do it a bunch of times, it still won't screw you!
$var = (htmlspecialchars_decode($var) == $var) ? htmlspecialchars($var) : $var;
$var = (htmlspecialchars_decode($var) == $var) ? htmlspecialchars($var) : $var;
echo $var; // still outputs Blue & yellow make green.
?>
Put it in a function. Add it to the method of some abstract data class.
benharold at mac dot com ¶
4 years ago
If you use `htmlspecialchars()` to change things like the ampersand (&) into it's HTML equivalent (&), you might run into a situation where you mistakenly pass the same string to the function twice, resulting in things appearing on your website like, as I call it, the ampersanded amp; "&". Clearly nobody want's "&" on his or her web page where there is supposed to be just an ampersand. Here's a quick and easy trick to make sure this doesn't happen:
<?php
$var = "This is a string that could be passed to htmlspecialchars multiple times.";
if (htmlspecialchars_decode($var) == $var) {
$var = htmlspecialchars($var);
}
echo $var;
?>
Now, if your dealing with text that is a mixed bag (has HTML entities and non-HTML entities) you're on your own.
geoffers at gmail dot com ¶
7 years ago
For PHP4 Compatibility:
<?php
function htmlspecialchars_decode_php4 ($str) {
return strtr($str, array_flip(get_html_translation_table(HTML_SPECIALCHARS)));
}
?>
geoffers@gmail ¶
7 years ago
[Update of previous note, having noticed I forgot to put in quote style]
PHP4 Compatible function:
<?php
function htmlspecialchars_decode_php4 ($str, $quote_style = ENT_COMPAT) {
return strtr($str, array_flip(get_html_translation_table(HTML_SPECIALCHARS, $quote_style)));
}
?>
Anonymous ¶
6 years ago
This should be the best way to do it.
(Reposted because the other one seems a bit slower and because those who used the code under called it htmlspecialchars_decode_php4)
<?php
if ( !function_exists('htmlspecialchars_decode') )
{
function htmlspecialchars_decode($text)
{
return strtr($text, array_flip(get_html_translation_table(HTML_SPECIALCHARS)));
}
}
?>
pinkgothic at gmail dot com ¶
3 years ago
Keep in mind that you should never trust user input - particularly for "mixed-bag" input containing a combination of plain text and markup or scripting code.
Why?
Well, consider someone sending '&<script>alert('XSS');</script>' to your PHP script:
<?php
$var = "&<script>alert('XSS');</script>";
$var = (htmlspecialchars_decode($var) == $var) ? htmlspecialchars($var) : $var;
echo $var;
?>
Since '&' decodes into '&', (htmlspecialchars_decode($var) == $var) will be -false-, thus returning $var without that it's escaped. In consequence, the script-tags are untouched, and you've just opened yourself to XSS.
There is, unfortunately, no reliable way to determine whether HTML is escaped or not that does not come with this caveat that I know of. Rather than try and catch the case 'I've already encoded this', you are better off avoiding double-escaping by simply escaping the HTML as close to the actual output as you can muster, e.g. in the view in an MVC development structure.
Wout ¶
5 years ago
The following replacement for PHP 4 is a little more complete, as the quote_style is taken into account as well:
if (!function_exists("htmlspecialchars_decode")) {
function htmlspecialchars_decode($string, $quote_style = ENT_COMPAT) {
return strtr($string, array_flip(get_html_translation_table(HTML_SPECIALCHARS, $quote_style)));
}
}
TheSin ¶
7 years ago
Here is how you can get this function in php < 5.1, just make sure this function is before you try and call the function.
if (!function_exists('htmlspecialchars_decode')) {
function htmlspecialchars_decode($str, $options="") {
$trans = get_html_translation_table(HTML_SPECIALCHARS, $options);
$decode = ARRAY();
foreach ($trans AS $char=>$entity) {
$decode[$entity] = $char;
}
$str = strtr($str, $decode);
return $str;
}
}
or-k at or-k dot com ¶
7 years ago
that works also with ä and " and so on.
get_html_translation_table(HTML_ENTITIES) => offers more characters than HTML_SPECIALCHARS
function htmlspecialchars_decode_PHP4($uSTR)
{
return strtr($uSTR, array_flip(get_html_translation_table(HTML_ENTITIES, ENT_QUOTES)));
}
se at designlinks dot net ¶
7 years ago
The code supplied by or-k at or-k dot com (14-Sep-2005 09:15) is better served using html_entity_decode() for PHP>=4.3.0.
geoffers@gmail (14-Jul-2005 01:38) offers the best htmlspecialchars_decode() for php4 users.
selimx at live dot com ¶
2 years ago
this function
<?php
function htmlkarakter($string)
{
$string = str_replace(array("<", ">", '&', ''', '"','<', '>'), array("<", ">",'&','\'','"','<','>'), htmlspecialchars_decode($string, ENT_NOQUOTES));
return $string;
}
?>
Before
<description><div class="google-ad1">
<script type='text/javascript'>
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</script>
</div>
after using the function
<div class="google-ad1">
<script type='text/javascript'>
GA_googleFillSlot("EW_News_300x250");
</script>