An important note below about using this function to secure your application against Cross Site Scripting (XSS) vulnerabilities.
When printing user input in an attribute of an HTML tag, the default configuration of htmlEntities() doesn't protect you against XSS, when using single quotes to define the border of the tag's attribute-value. XSS is then possible by injecting a single quote:
<?php
$_GET['a'] = "#000' onload='alert(document.cookie)";
?>
XSS possible (insecure):
<?php
$href = htmlEntities($_GET['a']);
print "<body bgcolor='$href'>"; # results in: <body bgcolor='#000' onload='alert(document.cookie)'>
?>
Use the 'ENT_QUOTES' quote style option, to ensure no XSS is possible and your application is secure:
<?php
$href = htmlEntities($_GET['a'], ENT_QUOTES);
print "<body bgcolor='$href'>"; # results in: <body bgcolor='#000' onload='alert(document.cookie)'>
?>
The 'ENT_QUOTES' option doesn't protect you against javascript evaluation in certain tag's attributes, like the 'href' attribute of the 'a' tag. When clicked on the link below, the given JavaScript will get executed:
<?php
$_GET['a'] = 'javascript:alert(document.cookie)';
$href = htmlEntities($_GET['a'], ENT_QUOTES);
print "<a href='$href'>link</a>"; # results in: <a href='javascript:alert(document.cookie)'>link</a>
?>
htmlentities
(PHP 4, PHP 5, PHP 7)
htmlentities — 해당하는 모든 문자를 HTML 엔티티로 변환
설명
string htmlentities
( string
$string
[, int $quote_style
[, string $charset
[, bool $double_encode
]]] )htmlentities()는 HTML 문자 엔티티에 존재하는 모든 문자를 엔티티로 변환하는 점을 제외하면, htmlspecialchars()와 완전히 동일합니다.
디코드(역변환)하려면 html_entity_decode()를 사용할 수 있습니다.
인수
-
string -
입력 문자열.
-
quote_style -
htmlspecialchars()와 같게, 두번째에 위치하는 선택적인
quote_style인수는 '홑따옴표'와 "겹따옴표"를 어떻게 처리할지 정의합니다. 아래의 세 상수 중 하나를 가질 수 있으며, 기본값은ENT_COMPAT입니다:사용할 수 있는 quote_style상수상수명 설명 ENT_COMPAT겹따옴표만 변환합니다. ENT_QUOTES홑따옴표와 겹따옴표 모두 변환합니다. ENT_NOQUOTES홑따옴표와 겹따옴표 모두 변환하지 않습니다. -
charset -
htmlspecialchars()와 같게, 세번째에 위치하는 선택적인
charset인수는 변환에 사용할 문자셋을 정의합니다. 현재 기본값은 ISO-8859-1 문자셋입니다.PHP 4.3.0 이상에서 다음 문자셋을 지원합니다.
지원 문자셋 문자셋 다른 이름 설명 ISO-8859-1 ISO8859-1 서부 유럽어, Latin-1. ISO-8859-15 ISO8859-15 서부 유럽어, Latin-9. 유로 사인, Latin-1(ISO-8859-1)에 빠진 프랑스어와 핀란드어 문자 추가. UTF-8 아스키 호환 멀티바이트 8비트 유니코드. cp866 ibm866, 866 DOS-특정 키릴 문자셋. 이 문자셋은 4.3.2부터 지원합니다. cp1251 Windows-1251, win-1251, 1251 윈도우-특정 키릴 문자셋. 이 문자셋은 4.3.2부터 지원합니다. cp1252 Windows-1252, 1252 윈도우 특정 서부 유럽어 문자셋 KOI8-R koi8-ru, koi8r 러시아어. 이 문자셋은 4.3.2부터 지원합니다. BIG5 950 중국어 번체, 주로 대만에서 사용. GB2312 936 중국어 간체, 국가 표준 문자셋. BIG5-HKSCS 홍콩 확장을 포함한 Big5, 중국어 번체. Shift_JIS SJIS, 932 일본어. EUC-JP EUCJP 일본어. Note: 다른 문자셋에 대해서는 ISO-8859-1을 사용합니다.
-
double_encode -
double_encode를 끄면, PHP는 이미 존재하는 html 엔티티를 인코드하지 않습니다. 기본값으로는 모두 변환합니다.
반환값
인코드한 문자열을 반환합니다.
변경점
| 버전 | 설명 |
|---|---|
| 5.2.3 |
double_encode 인수 추가.
|
| 4.1.0 |
charset 인수 추가.
|
| 4.0.3 |
quote_style 인수 추가.
|
예제
Example #1 htmlentities() 예제
<?php
$str = "A 'quote' is <b>bold</b>";
// 출력: A 'quote' is <b>bold</b>
echo htmlentities($str);
// 출력: A 'quote' is <b>bold</b>
echo htmlentities($str, ENT_QUOTES);
?>
참고
- html_entity_decode() - 모든 HTML 엔티티를 해당하는 문자로 변환
- get_html_translation_table() - htmlspecialchars와 htmlentities에서 사용하는 변환표를 반환합니다
- htmlspecialchars() - 특수 문자를 HTML 엔터티로 변환
- nl2br() - 문자열의 모든 줄바꿈 앞에 HTML 줄바꿈 태그를 삽입
- urlencode() - 문자열을 URL 인코드
add a note
User Contributed Notes 21 notes
Sijmen Ruwhof ¶
13 years ago
q (dot) rendeiro (at) gmail (dot) com ¶
17 years ago
I've seen lots of functions to convert all the entities, but I needed to do a fulltext search in a db field that had named entities instead of numeric entities (edited by tinymce), so I searched the tinymce source and found a string with the value->entity mapping. So, i wrote the following function to encode the user's query with named entities.
The string I used is different of the original, because i didn't want to convert ' or ". The string is too long, so I had to cut it. To get the original check TinyMCE source and search for nbsp or other entity ;)
<?php
$entities_unmatched = explode(',', '160,nbsp,161,iexcl,162,cent, [...] ');
$even = 1;
foreach($entities_unmatched as $c) {
if($even) {
$ord = $c;
} else {
$entities_table[$ord] = $c;
}
$even = 1 - $even;
}
function encode_named_entities($str) {
global $entities_table;
$encoded_str = '';
for($i = 0; $i < strlen($str); $i++) {
$ent = @$entities_table[ord($str{$i})];
if($ent) {
$encoded_str .= "&$ent;";
} else {
$encoded_str .= $str{$i};
}
}
return $encoded_str;
}
?>
realcj at g mail dt com ¶
17 years ago
If you are building a loadvars page for Flash and have problems with special chars such as " & ", " ' " etc, you should escape them for flash:
Try trace(escape("&")); in flash' actionscript to see the escape code for &;
% = %25
& = %26
' = %27
<?php
function flashentities($string){
return str_replace(array("&","'"),array("%26","%27"),$string);
}
?>
Those are the two that concerned me. YMMV.
hajo-p ¶
10 years ago
The flag ENT_HTML5 also strips newline chars like \n with htmlentities while htmlspecialchars is not affected by that.
If you want to use nl2br on that string afterwards you might end up searching the problem like i did. This does not apply to other flags like e.g. ENT_XHTML which confused me.
Tested this with PHP 5.4 / 5.5 / 5.6-dev with same results, so it seems that this is an intended "feature".
ustimenko dot alexander at gmail dot com ¶
12 years ago
For those Spanish (and not only) folks, that want their national letters back after htmlentities :)
<?php
protected function _decodeAccented($encodedValue, $options = array()) {
$options += array(
'quote' => ENT_NOQUOTES,
'encoding' => 'UTF-8',
);
return preg_replace_callback(
'/&\w(acute|uml|tilde);/',
create_function(
'$m',
'return html_entity_decode($m[0], ' . $options['quote'] . ', "' .
$options['encoding'] . '");'
),
$encodedValue
);
}
?>
phil at lavin dot me dot uk ¶
14 years ago
The following will make a string completely safe for XML:
<?php
function philsXMLClean($strin) {
$strout = null;
for ($i = 0; $i < strlen($strin); $i++) {
$ord = ord($strin[$i]);
if (($ord > 0 && $ord < 32) || ($ord >= 127)) {
$strout .= "&#{$ord};";
}
else {
switch ($strin[$i]) {
case '<':
$strout .= '<';
break;
case '>':
$strout .= '>';
break;
case '&':
$strout .= '&';
break;
case '"':
$strout .= '"';
break;
default:
$strout .= $strin[$i];
}
}
}
return $strout;
}
?>
Waygood ¶
12 years ago
When putting values inside comment tags <!-- --> you should replace -- with -- too, as this would end your tag and show the rest of the comment.
n at erui dot eu ¶
12 years ago
html entities does not encode all unicode characters. It encodes what it can [all of latin1], and the others slip through. Љ is the nasty I use. I have searched for a function which encodes everything, but in the end I wrote this. This is as simple as I can get it. Consult an ansii table to custom include/omit chars you want/don't. I'm sure it's not that fast.
// Unicode-proof htmlentities.
// Returns 'normal' chars as chars and weirdos as numeric html entites.
function superentities( $str ){
// get rid of existing entities else double-escape
$str = html_entity_decode(stripslashes($str),ENT_QUOTES,'UTF-8');
$ar = preg_split('/(?<!^)(?!$)/u', $str ); // return array of every multi-byte character
foreach ($ar as $c){
$o = ord($c);
if ( (strlen($c) > 1) || /* multi-byte [unicode] */
($o <32 || $o > 126) || /* <- control / latin weirdos -> */
($o >33 && $o < 40) ||/* quotes + ambersand */
($o >59 && $o < 63) /* html */
) {
// convert to numeric entity
$c = mb_encode_numericentity($c,array (0x0, 0xffff, 0, 0xffff), 'UTF-8');
}
$str2 .= $c;
}
return $str2;
}
wd at NOSPAMwd dot it ¶
12 years ago
Hi there,
after several and several tests, I figured out that dot:
- htmlentities() function remove characters like "à","è",etc when you specify a flag and a charset
- htmlentities() function DOES NOT remove characters like those above when you DO NOT specify anything
So, let's assume that..
<?php
$str = "Hèèèllooo";
$res_1 = htmlentities($str, ENT_QUOTES, "UTF-8");
$res_2 = htmlentities($str);
echo var_dump($res_1); // Result: string '' (length=0)
echo var_dump($res_2); // string 'Hèèèllooo' (length=30)
?>
I used this for a textarea content for comments. Anyway, note that using the "$res_2" form the function will leave unconverted single/double quotes. At this point you should use str_replace() function to perform the characters but be careful because..
<?php
$str = "'Hèèèllooo'";
$res_2 = str_replace("'","'",$str);
$res_2 = htmlentities($str);
echo var_dump($res_2); // string '&#039;Hèèèllooo&#039;'
$res_3 = htmlentities($str);
$res_3 = str_replace("'","'",$res_3);
echo var_dump($res_3); // string ''Hèèèllooo'' --> Nice
?>
Hope it will helps you.
Regards,
W.D.
robin at robinwinslow dot co dot uk ¶
13 years ago
htmlentities seems to have changed at some point between version 5.1.6 and 5.3.3, such that it now returns an empty string for anything containing a pound sign:
$ php -v
PHP 5.1.6 (cli) (built: May 22 2008 09:08:44)
$ php -r "echo htmlentities('£hello', null, 'utf-8');"
£hello
$
$ php -v
PHP 5.3.3 (cli) (built: Aug 19 2010 12:07:49)
$ php -r "echo htmlentities('£hello', null, 'utf-8');"
$
(Returns an empty string the second time)
Just a heads up.
Bassie (: ¶
21 years ago
Note that you'll have use htmlentities() before any other function who'll edit text like nl2br().
If you use nl2br() first, the htmlentities() function will change < br > to <br>.
jake_mcmahon at hotmail dot com ¶
19 years ago
This fuction is particularly useful against XSS (cross-site-scripting-). XSS makes use of holes in code, whether it be in Javascript or PHP. XSS often, if not always, uses HTML entities to do its evil deeds, so this function in co-operation with your scripts (particularly search or submitting scripts) is a very useful tool in combatting "H4X0rz".
admin at wapforum dot rs ¶
13 years ago
A useful little function to convert the symbols in the different inputs.
<?php
function ConvertSimbols($var, $ConvertQuotes = 0) {
if ($ConvertQuotes > 0) {
$var = htmlentities($var, ENT_NOQUOTES, 'UTF-8');
$var = str_replace('\"', '', $var);
$var = str_replace("\'", '', $var);
} else {
$var = htmlentities($var, ENT_QUOTES, 'UTF-8');
}
return $var;
}
?>
Usage with quotes for example message:
$message = ConvertSimbols($message);
Usage without quotes for example link:
$link = ConvertSimbols($link, 1);
Jeff ¶
5 years ago
There is a feature when writing to XML using an AJAX call to PHP that rarely is mentioned. I struggled for many hours using htmlentities() because what was getting written to my XML document was not as expected. I naturally assumed that I should be converting my strings before writing them to XML to adhere to XML rules on illegal characters. To my surprise, when converting with htmlentities() or htmlspecialchars() and then writing to an XML file, the resulting ampersands get converted afterwards! Consider the following example:
<?php
$str = "<b>I am cool</b>" ;
$str = htmlentities($str) ;
?>
When you append $str to an XML element and save() the document, you would expect the XML document's source code to look something like this:
<ele><b>I am cool</b></ele>
But that is not what happens. The resulting ampersands get converted by PHP automatically to & and your source code ends up looking like this:
<ele>&lt;b&gt;I am cool&lt;/b&gt;</ele>
As you can see, this creates problems when trying to output the XML data back to HTML. It is important to remember that when writing to XML this way, special characters like ">" and "<"; PHP converts them automatically and there becomes no need to use htmlentities() in certain cases. I assume this feature is in place to aid with passing data through header queries, to avoid reserved characters conflicting with others in a header query (e.g. & or =). Now I understand this may not be the case with older versions of PHP and that this might be a feature of my version (PHP version 5.6.32). With older versions, I assume using htmlentities() or htmlspecialchars() is a must, as stated with previous notes here. Also I use the charset UTF-8 in my HTML and XML and am not sure if this also effects the results I get.
Anyway, I struggled for many hours with using htmlentities() to convert strings for XML writing and saving, when all I had to do was simply not use the function and let PHP convert my strings for me. I hope this helps because I would think I am not the only one who has struggled with this situation.
h_guillaume at hotmail dot com ¶
13 years ago
I use this function to encode all the xml entities and also all the &something; that are not defined in xml like ™
You can also decode what you encode with my decode function.
My function works a little like the htmlentities.
You can also add other string to the array if you want to exclude them from the encoding.
<?php
function xml_entity_decode($text, $charset = 'Windows-1252'){
// Double decode, so if the value was &trade; it will become Trademark
$text = html_entity_decode($text, ENT_COMPAT, $charset);
$text = html_entity_decode($text, ENT_COMPAT, $charset);
return $text;
}
function xml_entities($text, $charset = 'Windows-1252'){
// Debug and Test
// $text = "test & ™ &trade; abc ® &reg; -";
// First we encode html characters that are also invalid in xml
$text = htmlentities($text, ENT_COMPAT, $charset, false);
// XML character entity array from Wiki
// Note: ' is useless in UTF-8 or in UTF-16
$arr_xml_special_char = array(""","&","'","<",">");
// Building the regex string to exclude all strings with xml special char
$arr_xml_special_char_regex = "(?";
foreach($arr_xml_special_char as $key => $value){
$arr_xml_special_char_regex .= "(?!$value)";
}
$arr_xml_special_char_regex .= ")";
// Scan the array for &something_not_xml; syntax
$pattern = "/$arr_xml_special_char_regex&([a-zA-Z0-9]+;)/";
// Replace the &something_not_xml; with &something_not_xml;
$replacement = '&${1}';
return preg_replace($pattern, $replacement, $text);
}
?>
steve at mcdragonsoftware dot com ¶
12 years ago
I'm glad 5.4 has xml support, but many of us are working with older installations, some of us still have to use PHP4. If you're like me you've been frustrated with trying to use htmlentites/htmlspecial chars with xml output. I was hoping to find an option to force numeric encoding, lacking that, I have written my own xmlencode function, which I now offer:
usage:
$string xmlencode( $string )
it will use htmlspecialchars for the valid xml entities amp, quote, lt, gt, (apos) and return the numeric entity for all other non alpha-numeric characters.
-------------------------------------------
<?php
if( !function_exists( 'xmlentities' ) ) {
function xmlentities( $string ) {
$not_in_list = "A-Z0-9a-z\s_-";
return preg_replace_callback( "/[^{$not_in_list}]/" , 'get_xml_entity_at_index_0' , $string );
}
function get_xml_entity_at_index_0( $CHAR ) {
if( !is_string( $CHAR[0] ) || ( strlen( $CHAR[0] ) > 1 ) ) {
die( "function: 'get_xml_entity_at_index_0' requires data type: 'char' (single character). '{$CHAR[0]}' does not match this type." );
}
switch( $CHAR[0] ) {
case "'": case '"': case '&': case '<': case '>':
return htmlspecialchars( $CHAR[0], ENT_QUOTES ); break;
default:
return numeric_entity_4_char($CHAR[0]); break;
}
}
function numeric_entity_4_char( $char ) {
return "&#".str_pad(ord($char), 3, '0', STR_PAD_LEFT).";";
}
}
?>
Tom Walter ¶
15 years ago
Note that as of 5.2.5 it appears that if the input string contains a character that is not valid for the output encoding you've specified, then this function returns null.
You might expect it to just strip the invalid char, but it doesn't.
You can strip the chars yourself like so:
iconv('utf-8','utf-8',$str);
You can combine that with htmlentities also:
$str = htmlentities(iconv('UTF-8', 'UTF-8//IGNORE', $str, ENT_QUOTES, 'UTF-8');
Should give you a string with htmlentities encoded to utf-8, and any unsupported chars stripped.
2962051004 at qq dot com ¶
5 years ago
<?php
/**
* 将中文转为Html实体
* Convert Chinese in HTML to entity
* Author QiangGe
* Mail 2962051004@qq.com
*
*/
$str = <<<EOT
你好 world
EOT;
function ChineseToEntity($str) {
return preg_replace_callback(
'/[\x{4e00}-\x{9fa5}]/u', // utf-8
// '/[\x7f-\xff]+/', // if gb2312
function ($matches) {
$json = json_encode(array($matches[0]));
preg_match('/\[\"(.*)\"\]/', $json, $arr);
/*
* 通过json_encode函数将中文转为unicode
* 然后用正则取出unicode
* Turn the Chinese into Unicode through the json_encode function, then extract Unicode from regular.
* I think this idea is seamless.
*/
return '&#x'. str_replace('\\u', '', $arr[1]). ';';
}, $str
);
}
echo ChineseToEntity($str);
// 你好 world
chris at ocproducts dot com ¶
7 years ago
This function throws a warning on bad input even if ENT_SUBSTITUTE is set, so be prepared for this.
za at byza dot it ¶
16 years ago
Trouble when using files with different charset?
htmlentities and html_entity_decode can be used to translate between charset!
Sample function:
<?php
function utf2latin($text) {
$text=htmlentities($text,ENT_COMPAT,'UTF-8');
return html_entity_decode($text,ENT_COMPAT,'ISO-8859-1');
}
?>
drallen at cs dot uwaterloo dot ca ¶
13 years ago
A pointer to http://www.php.net/manual/en/function.mb-convert-encoding.php if your intention is to translate *all* characters in a charset to their corresponding HTML entities, not just named characters. Non-named characters will be replaced with HTML numeric encoding. eg:
$text = mb_convert_encoding($text, 'HTML-ENTITIES', "UTF-8");
