htmlspecialchars

(PHP 4, PHP 5, PHP 7, PHP 8)

htmlspecialcharsПреобразовывает специальные символы в HTML-сущности

Описание

htmlspecialchars(
    string $string,
    int $flags = ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401,
    ?string $encoding = null,
    bool $double_encode = true
): string

Ряд символов в HTML несёт отдельный смысл и для сохранения значения такие символы представляют HTML-сущностями. Функция возвращает строку с этими преобразованиями. Вместо этой функции вызывают функцию htmlentities(), когда требуется перевести каждую входную подстроку, у которой есть связанная именованная сущность.

Если у входной строки, которую передали в эту функцию, и результирующего документа одинаковый набор символов, то этой функции хватит, чтобы подготовить входные данные для вставки в бо́льшую часть контекстов HTML-документа. Однако, если данные содержат символы, которые не закодированы в наборе символов результирующего документа, и требуется сохранить эти символы (как числовые или именованные сущности), то как этой функции, так и функции htmlentities() (которые преобразовывают только подстроки, у которых есть эквивалентные именованные сущности), будет недостаточно. Вместо них пользуются функцией mb_encode_numericentity().

Преобразования
Символ Замена
& (амперсанд) &
" (двойные кавычки) ", без флага ENT_NOQUOTES
' (одинарные кавычки) ' для документов стандарта ENT_HTML401 или ' для документов стандартов ENT_XML1, ENT_XHTML или ENT_HTML5, но только с флагом ENT_QUOTES
< (меньше) &lt;
> (больше) &gt;

Список параметров

string

Конвертируемая строка (string).

flags

Битовая маска из следующих флагов, которые определяют, как обрабатывать кавычки, неправильные последовательности кодовых единиц и тип документа. Флаги по умолчанию: ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401.

Доступные значения параметра flags
Название константы Описание
ENT_COMPAT Преобразовывает двойные кавычки, одинарные кавычки не изменяются.
ENT_QUOTES Преобразовывает как двойные, так и одинарные кавычки.
ENT_NOQUOTES Оставляет без изменения как двойные, так и одинарные кавычки.
ENT_IGNORE Без предупреждения отбрасывает неправильные последовательности кодовых единиц вместо возврата пустой строки. Передача этого флага не рекомендуется, поскольку это » небезопасно.
ENT_SUBSTITUTE Заменяет неправильные последовательности кодовых единиц символом замены Юникода вместо возврата пустой строки: U+FFFD для строк в кодировке UTF-8 и &#FFFD; для строк в других кодировках.
ENT_DISALLOWED Заменяет неверные кодовые точки для заданного типа документа символом замены юникода U+FFFD для строк в кодировке UTF-8 или &#FFFD; для строк в других кодировках вместо того, чтобы оставлять всё как есть. Это бывает полезно для правильного оформления XML-документов, в которые встроили внешнее содержимое.
ENT_HTML401 Обрабатывает код по правилам стандарта HTML 4.01.
ENT_XML1 Обрабатывает код по правилам стандарта XML 1.
ENT_XHTML Обрабатывает код по правилам стандарта XHTML.
ENT_HTML5 Обрабатывает код по правилам стандарта HTML 5.

encoding

Необязательный аргумент, который определяет кодировку для преобразования символов.

Функция примет за значение по умолчанию для параметра encoding значение опции конфигурации default_charset, если параметр опустили.

Хотя технически этот аргумент необязателен, настоятельно рекомендуется указать правильное значение для кода, на случай если значение опции default_charset окажется неправильным для входных данных.

Для целей этой функции кодировки ISO-8859-1, ISO-8859-15, UTF-8, cp866, cp1251, cp1252 и KOI8-R практически эквивалентны, при условии, что сама строка string содержит допустимые для заданной кодировки символы, поскольку символы, которые изменяет функция htmlspecialchars(), занимают одинаковые позиции в перечисленных кодировках.

Функция поддерживает следующие кодировки:

Кодировки, которые поддерживает функция
Кодировка Псевдонимы Описание
ISO-8859-1 ISO8859-1 Западно-Европейская кодировка с набором символов Latin-1.
ISO-8859-5 ISO8859-5 Кириллическая кодировка с набором символов Latin/Cyrillic; применяют редко.
ISO-8859-15 ISO8859-15 Западно-Европейская кодировка с набором символов Latin-9. Добавляет к набору символов Latin-1 кодировки ISO-8859-1 знак евро, французские и финские буквы.
UTF-8   ASCII-совместимая многобайтовая 8-битная кодировка Unicode.
cp866 ibm866, 866 Кириллическая кодировка, которую применяют в семействе операционных систем DOS.
cp1251 Windows-1251, win-1251, 1251 Кириллическая кодировка, которую применяют в операционных системах Windows.
cp1252 Windows-1252, 1252 Западно-Европейская кодировка, которую применяют в операционных системах Windows.
KOI8-R koi8-ru, koi8r Русская кодировка.
BIG5 950 Кодировка с набором символов Traditional Chinese (Традиционный китайский), которую применяют в основном на Тайване.
GB2312 936 Стандартная национальная кодировка с набором символов Simplified Chinese (Упрощённый китайский).
BIG5-HKSCS   Кодировка Big5 с расширениями для Гонконга с набором символов Traditional Chinese (Традиционный китайский).
Shift_JIS SJIS, SJIS-win, cp932, 932 Японская кодировка.
EUC-JP EUCJP, eucJP-win Японская кодировка.
MacRoman   Кодировка, которую использовала операционная система Mac OS.
''   Пустая строка активирует режим определения кодировки из файла скрипта (Zend multibyte), директивы default_charset и текущей локали (смотрите описание функций nl_langinfo() и setlocale()), в перечисленном порядке. Не рекомендуется использовать.

Замечание: Другие кодировки функция не распознаёт. Вместо других кодировок функция будет использовать кодировку по умолчанию и выдаст предупреждение.

double_encode

Когда параметр double_encode отключён, PHP не будет кодировать существующие HTML-сущности. По умолчанию функция преобразовывает каждый символ.

Возвращаемые значения

Функция возвращает преобразованную строку (string).

Функция вернёт пустую строку, если входная строка string содержит недопустимую для кодировки encoding последовательность кодовых единиц, если только не установили флаг ENT_IGNORE или ENT_SUBSTITUTE.

Список изменений

Версия Описание
8.1.0 Значение по умолчанию для параметра flags изменили с ENT_COMPAT на ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401.

Примеры

Пример #1 Пример использования функции htmlspecialchars()

<?php

$new
= htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES);
echo
$new; // &lt;a href=&#039;test&#039;&gt;Test&lt;/a&gt;

?>

Примечания

Замечание:

Обратите внимание, функция выполняет только описанные преобразования. Для преобразования всех символов вызывают функцию htmlentities().

Замечание:

Когда значение параметра flags неоднозначно, функция применяет следующие правила:

Смотрите также

  • get_html_translation_table() - Возвращает таблицу преобразований, используемую функциями htmlspecialchars и htmlentities
  • htmlspecialchars_decode() - Преобразовывает специальные HTML-сущности обратно в символы
  • strip_tags() - Удаляет HTML- и PHP-теги из строки
  • htmlentities() - Преобразовывает возможные символы в HTML-сущности
  • nl2br() - Вставляет HTML-код разрыва строки перед каждым переводом строки

add a note

User Contributed Notes 21 notes

up
75
Dave
11 years ago
As of PHP 5.4 they changed default encoding from "ISO-8859-1" to "UTF-8". So if you get null from htmlspecialchars or htmlentities

where you have only set
<?php
echo htmlspecialchars($string);
echo
htmlentities($string);
?>

you can fix it by
<?php
echo htmlspecialchars($string, ENT_COMPAT,'ISO-8859-1', true);
echo
htmlentities($string, ENT_COMPAT,'ISO-8859-1', true);
?>

On linux you can find the scripts you need to fix by

grep -Rl "htmlspecialchars\\|htmlentities" /path/to/php/scripts/
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48
Mike Robinson
11 years ago
Unfortunately, as far as I can tell, the PHP devs did not provide ANY way to set the default encoding used by htmlspecialchars() or htmlentities(), even though they changed the default encoding in PHP 5.4 (*golf clap for PHP devs*). To save someone the time of trying it, this does not work:

<?php
ini_set
('default_charset', $charset); // doesn't work.
?>

Unfortunately, the only way to not have to explicitly provide the second and third parameter every single time this function is called (which gets extremely tedious) is to write your own function as a wrapper:

<?php
define
('CHARSET', 'ISO-8859-1');
define('REPLACE_FLAGS', ENT_COMPAT | ENT_XHTML);

function
html($string) {
return
htmlspecialchars($string, REPLACE_FLAGS, CHARSET);
}

echo
html("ñ"); // works
?>

You can do the same for htmlentities()
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8
Daniel Klein
2 years ago
Because the documentation says

int $flags = ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401

you would think that ENT_HTML401 is important. But as the notes mention, ENT_HTML401 is the default if you don't specify the doc type. This is because ENT_HTML401 === 0. So

int $flags = ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401

is exactly equivalent to

int $flags = ENT_QUOTES | ENT_SUBSTITUTE
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23
Thomasvdbulk at gmail dot com
13 years ago
i searched for a while for a script, that could see the difference between an html tag and just < and > placed in the text,
the reason is that i recieve text from a database,
wich is inserted by an html form, and contains text and html tags,
the text can contain < and >, so does the tags,
with htmlspecialchars you can validate your text to XHTML,
but you'll also change the tags, like <b> to &lt;b&gt;,
so i needed a script that could see the difference between those two...
but i couldn't find one so i made my own one,
i havent fully tested it, but the parts i tested worked perfect!
just for people that were searching for something like this,
it may looks big, could be done easier, but it works for me, so im happy.

<?php
function fixtags($text){
$text = htmlspecialchars($text);
$text = preg_replace("/=/", "=\"\"", $text);
$text = preg_replace("/&quot;/", "&quot;\"", $text);
$tags = "/&lt;(\/|)(\w*)(\ |)(\w*)([\\\=]*)(?|(\")\"&quot;\"|)(?|(.*)?&quot;(\")|)([\ ]?)(\/|)&gt;/i";
$replacement = "<$1$2$3$4$5$6$7$8$9$10>";
$text = preg_replace($tags, $replacement, $text);
$text = preg_replace("/=\"\"/", "=", $text);
return
$text;
}
?>

an example:

<?php
$string
= "
this is smaller < than this<br />
this is greater > than this<br />
this is the same = as this<br />
<a href=\"http://www.example.com/example.php?test=test\">This is a link</a><br />
<b>Bold</b> <i>italic</i> etc..."
;
echo
fixtags($string);
?>

will echo:
this is smaller &lt; than this<br />
this is greater &gt; than this<br />
this is the same = as this<br />
<a href="http://www.example.com/example.php?test=test">This is a link</a><br />
<b>Bold</b> <i>italic</i> etc...

I hope its helpfull!!
up
17
Kenneth Kin Lum
15 years ago
if your goal is just to protect your page from Cross Site Scripting (XSS) attack, or just to show HTML tags on a web page (showing <body> on the page, for example), then using htmlspecialchars() is good enough and better than using htmlentities(). A minor point is htmlspecialchars() is faster than htmlentities(). A more important point is, when we use htmlspecialchars($s) in our code, it is automatically compatible with UTF-8 string. Otherwise, if we use htmlentities($s), and there happens to be foreign characters in the string $s in UTF-8 encoding, then htmlentities() is going to mess it up, as it modifies the byte 0x80 to 0xFF in the string to entities like &eacute;. (unless you specifically provide a second argument and a third argument to htmlentities(), with the third argument being "UTF-8").

The reason htmlspecialchars($s) already works with UTF-8 string is that, it changes bytes that are in the range 0x00 to 0x7F to &lt; etc, while leaving bytes in the range 0x80 to 0xFF unchanged. We may wonder whether htmlspecialchars() may accidentally change any byte in a 2 to 4 byte UTF-8 character to &lt; etc. The answer is, it won't. When a UTF-8 character is 2 to 4 bytes long, all the bytes in this character is in the 0x80 to 0xFF range. None can be in the 0x00 to 0x7F range. When a UTF-8 character is 1 byte long, it is just the same as ASCII, which is 7 bit, from 0x00 to 0x7F. As a result, when a UTF-8 character is 1 byte long, htmlspecialchars($s) will do its job, and when the UTF-8 character is 2 to 4 bytes long, htmlspecialchars($s) will just pass those bytes unchanged. So htmlspecialchars($s) will do the same job no matter whether $s is in ASCII, ISO-8859-1 (Latin-1), or UTF-8.
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1
Killian Leroux
2 years ago
Thanks Thomasvdbulk for your workaround, I would like to add a precision:

When the HTML contains a link tag without new line before the script doesn't work :/

Your example:

<?php
$string
= "
this is smaller < than this<br />
this is greater > than this<br />
this is the same = as this<br />
<a href=\"http://www.example.com/example.php?test=test\">This is a link</a><br />
<b>Bold</b> <i>italic</i> etc..."
;
echo
fixtags($string);
?>

Works but this doesn't work:

<?php
$string
= "
this is smaller < than this<br />
this is greater > than this<br />
this is the same = as this<br /><a href=\"http://www.example.com/example.php?test=test\">This is a link</a><br />
<b>Bold</b> <i>italic</i> etc..."
;
echo
fixtags($string);
?>

So I add a little workaround at the beginning (before htmlspecialchars):

<?php
$text
= preg_replace('/<a/', "\r\n<a", $text);
?>

I don't like that but I don't find other solution... :/
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10
Felix D.
10 years ago
Another thing important to mention is that
htmlspecialchars(NULL)
returnes an empty string and not NULL!
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5
ASchmidt at Anamera dot net
3 years ago
One MUST specify ENT_HTML5 in addition to double_encode=false to avoid double-encoding.

The reason is that contrary to the documentation, double_encode=false will NOT unconditionally and globally prevent double-encoding of ALL existing entities. Crucially, it will only skip double-encoding for THOSE character entities that are explicitly valid for the document type chosen!

Since ENT_HTML5 references the most expansive list of character entities, it is the only setting that will be most lenient with existing character entities.

<?php
declare(strict_types=1);
$text = 'ampersand(&amp;), double quote(&quot;), single quote(&apos;), less than(&lt;), greater than(&gt;), numeric entities(&#x26;&#x22;&#x27;&#x3C;&#x3E;), HTML 5 entities(&plus;&comma;&excl;&dollar;&lpar;&ncedil;&euro;)';
$result3 = htmlspecialchars( $text, ENT_NOQUOTES | ENT_SUBSTITUTE, 'UTF-8', /*double_encode*/false );
$result4 = htmlspecialchars( $text, ENT_NOQUOTES | ENT_XML1 | ENT_SUBSTITUTE, 'UTF-8', /*double_encode*/false );
$result5 = htmlspecialchars( $text, ENT_NOQUOTES | ENT_XHTML | ENT_SUBSTITUTE, 'UTF-8', /*double_encode*/false );
$result6 = htmlspecialchars( $text, ENT_NOQUOTES | ENT_HTML5 | ENT_SUBSTITUTE, 'UTF-8', /*double_encode*/false );

echo
"<br />\r\nHTML 4.01:<br />\r\n", $result3,
"<br />\r\nXML 1:<br />\r\n", $result4,
"<br />\r\nXHTML:<br />\r\n", $result5,
"<br />\r\nHTML 5:<br />\r\n", $result6, "<br />\r\n";
?>

will produce:

HTML 4.01 (will NOT recognize single quote, but Euro):
ampersand(&), double quote("), single quote(&apos;), less than(<), greater than(>), numeric entities(&"'<>), HTML 5 entities(&plus;&comma;&excl;&dollar;&lpar;&ncedil;€)

XML 1 (WILL recognize single quote, but NOT Euro):
ampersand(&), double quote("), single quote('), less than(<), greater than(>), numeric entities(&"'<>), HTML 5 entities(&plus;&comma;&excl;&dollar;&lpar;&ncedil;&euro;)

XHTML (recognizes single quote and Euro):
ampersand(&), double quote("), single quote('), less than(<), greater than(>), numeric entities(&"'<>), HTML 5 entities(&plus;&comma;&excl;&dollar;&lpar;&ncedil;€)

HTML 5 (recognizes "all" valid character entities):
ampersand(&), double quote("), single quote('), less than(<), greater than(>), numeric entities(&"'<>), HTML 5 entities(+,!$(ņ€)
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11
ivan at lutrov dot com
13 years ago
Be careful, the "charset" argument IS case sensitive. This is counter-intuitive and serves no practical purpose because the HTML spec actually has the opposite.
up
3
qshing1437 at hotmail dot com
4 years ago
If you use htmlspecialchars() to escape any HTML attribute, make sure use double quote instead of single quote for the attribute.

For Example,

> Wrap with Single Quote
<?php
echo "<p title='" . htmlspecialchars("Hello\"s\'world") . "'">

// title will end up Hello"s\ and rest of the text after single quote will be cut off.
?>

> Wrap with Double quote :
<?php
echo '<p title="' . htmlspecialchars("Hello\"s\'world") . '"'>

// title will show up correctly as Hello"s'world
?>
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7
Anonymous
14 years ago
Just a few notes on how one can use htmlspecialchars() and htmlentities() to filter user input on forms for later display and/or database storage...

1. Use htmlspecialchars() to filter text input values for html input tags. i.e.,

echo '<input name=userdata type=text value="'.htmlspecialchars($data).'" />';


2. Use htmlentities() to filter the same data values for most other kinds of html tags, i.e.,

echo '<p>'.htmlentities($data).'</p>';

3. Use your database escape string function to filter the data for database updates & insertions, for instance, using postgresql,

pg_query($connection,"UPDATE datatable SET datavalue='".pg_escape_string($data)."'");


This strategy seems to work well and consistently, without restricting anything the user might like to type and display, while still providing a good deal of protection against a wide variety of html and database escape sequence injections, which might otherwise be introduced through deliberate and/or accidental input of such character sequences by users submitting their input data via html forms.
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4
Anonymous
14 years ago
This may seem obvious, but it caused me some frustration. If you try and use htmlspecialchars with the $charset argument set and the string you run it on is not actually the same charset you specify, you get any empty string returned without any notice/warning/error.

<?php

$ok_utf8
= "A valid UTF-8 string";
$bad_utf8 = "An invalid UTF-8 string";

var_dump(htmlspecialchars($bad_utf8, ENT_NOQUOTES, 'UTF-8')); // string(0) ""

var_dump(htmlspecialchars($ok_utf8, ENT_NOQUOTES, 'UTF-8')); // string(20) "A valid UTF-8 string"

?>

So make sure your charsets are consistent

<?php

$bad_utf8
= "An invalid UTF-8 string";

// make sure it's really UTF-8
$bad_utf8 = mb_convert_encoding($bad_utf8, 'UTF-8', mb_detect_encoding($bad_utf8));

var_dump(htmlspecialchars($bad_utf8, ENT_NOQUOTES, 'UTF-8')); // string(23) "An invalid UTF-8 string"

?>

I had this problem because a Mac user was submitting posts copy/pasted from a program and it contained weird chars in it.
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3
php dot net at orakio dot net
16 years ago
I was recently exploring some code when I saw this being used to make data safe for "SQL".

This function should not be used to make data SQL safe (although to prevent phishing it is perfectly good).

Here is an example of how NOT to use this function:

<?php
$username
= htmlspecialchars(trim("$_POST[username]"));

$uniqueuser = $realm_db->query("SELECT `login` FROM `accounts` WHERE `login` = '$username'");
?>

(Only other check on $_POST['username'] is to make sure it isn't empty which it is after trim on a white space only name)

The problem here is that it is left to default which allows single quote marks which are used in the sql query. Turning on magic quotes might fix it but you should not rely on magic quotes, in fact you should never use it and fix the code instead. There are also problems with \ not being escaped. Even if magic quotes were used there would be the problem of allowing usernames longer than the limit and having some really weird usernames given they are to be used outside of html, this just provide a front end for registering to another system using mysql. Of course using it on the output wouldn;t cause that problem.

Another way to make something of a fix would be to use ENT_QUOTE or do:

<?php
$uniqueuser
= $realm_db->query('SELECT `login` FROM `accounts` WHERE `login` = "'.$username.'";');
?>

Eitherway none of these solutions are good practice and are not entirely unflawed. This function should simply never be used in such a fashion.

I hope this will prevent newbies using this function incorrectly (as they apparently do).
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3
ryan at ryano dot net
23 years ago
Actually, if you're using >= 4.0.5, this should theoretically be quicker (less overhead anyway):

$text = str_replace(array("&gt;", "&lt;", "&quot;", "&amp;"), array(">", "<", "\"", "&"), $text);
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2
PoV
9 years ago
Be aware of the encoding of your source files!!!

Some of the suggestions here make reference to workarounds where you hard-code an encoding.

<?php
echo htmlspecialchars('<b>Wörmann</b>'); // Why isn't this working?
?>

As it turns out, it may actually be your text editor that is to blame.

As of PHP 5.4, htmlspecialchars now defaults to the UTF-8 encoding. That said, many text editors default to non-UTF encodings like ISO-8859-1 (i.e. Latin-1) or WIN-1252. If you change the encoding of the file to UTF-8, the code above will now work (i.e. the ö is encoded differently in UTF-8 and ISO-8859-1, and you need the UTF-8 version).

Make sure you are editing in UTF-8 Unicode mode! Check your UI or manual for how to convert files to Unicode. It's also a good idea to figure out where to look in your UI to see what the current file encoding is.
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1
minder at ufive dot unibe dot ch
11 years ago
Problem

In many PHP legacy products the function htmlspecialchars($string) is used to convert characters like < and > and quotes a.s.o to HTML-entities. That avoids the interpretation of HTML Tags and asymmetric quote situations.

Since PHP 5.4 for $string in htmlspecialchars($string) utf8 characters are expected if no charset is defined explicitly as third parameter in the function. Legacy products are mostly in Latin1 (alias iso-8859-1) what makes the functions htmlspecialchars(), htmlentites() and html_entity_decode() to return empty strings if a special character, e. g. a German Umlaut, is present in $string:

PHP<5.4

echo htmlspecialchars('<b>Woermann</b>') //Output: &lt;b&gt;Woermann&lt;b&gt;
echo htmlspecialchars('Wörmann') //Output: &lt;b&gt;Wörmann&lt;b&gt;

PHP=5.4

echo htmlspecialchars('<b>Woermann</b>') //Output: &lt;b&gt;Woermann&lt;b&gt;
echo htmlspecialchars('<b>Wörmann</b>') //Output: empty

Three alternative solutions

a) Not runnig legacy products on PHP 5.4
b) Change all find spots in your code from
htmlspecialchars($string) and *** to
htmlspecialchars($string, ENT_COMPAT | ENT_HTML401, 'ISO-8859-1')
c) Replace all htmlspecialchars() and *** with a new self-made function

*** The same is true for htmlentities() and html_entity_decode();

Solution c

1 Make Search and Replace in the concerned legacy project:
Search for: htmlspecialchars
Replace with: htmlXspecialchars
Search for: htmlentities
Replace with: htmlXentities
Search for: html_entity_decode
Replace with: htmlX_entity_decode
2a Copy and paste the following three functions into an existing already everywhere included PHP-file in your legacy project. (of course that PHP-file must be included only once per request, otherwise you will get a Redeclare Function Fatal Error).

function htmlXspecialchars($string, $ent=ENT_COMPAT, $charset='ISO-8859-1') {
return htmlspecialchars($string, $ent, $charset);
}

function htmlXentities($string, $ent=ENT_COMPAT, $charset='ISO-8859-1') {
return htmlentities($string, $ent, $charset);
}

function htmlX_entity_decode($string, $ent=ENT_COMPAT, $charset='ISO-8859-1') {
return html_entity_decode($string, $ent, $charset);
}

or 2b crate a new PHP-file containing the three functions mentioned above, let's say, z. B. htmlXfunctions.inc.php and include it on the first line of every PHP-file in your legacy product like this: require_once('htmlXfunctions.inc.php').
up
-1
nachitox2000 [at] hotmail [dot] com
14 years ago
I had problems with spanish special characters. So i think in using htmlspecialchars but my strings also contain HTML.
So I used this :) Hope it help

<?php
function htmlspanishchars($str)
{
return
str_replace(array("&lt;", "&gt;"), array("<", ">"), htmlspecialchars($str, ENT_NOQUOTES, "UTF-8"));
}
?>
up
-1
solar-energy
17 years ago
also see function "urlencode()", useful for passing text with ampersand and other special chars through url

(i.e. the text is encoded as if sent from form using GET method)

e.g.

<?php
echo "<a href='foo.php?text=".urlencode("foo?&bar!")."'>link</a>";
?>

produces

<a href='foo.php?text=foo%3F%26bar%21'>link</a>

and if the link is followed, the $_GET["text"] in foo.php will contain "foo?&bar!"
up
-2
_____ at luukku dot com
21 years ago
People, don't use ereg_replace for the most simple string replacing operations (replacing constant string with another).
Use str_replace.
up
-5
support at playnext dot ru
10 years ago
For those having problems after the change of default value of $encoding argument to UTF-8 since PHP 5.4.

If your old non-UTF8 projects ruined - pls consider:
1. http://php.net/manual/en/function.override-function.php
2. http://php.net/manual/ru/function.runkit-function-redefine.php

The idea - you override the built-in htmlspecialchars() function with your customized variant which is able to respect non UTF-8 default encoding. This small piece of code can be then easily inserted somewhere at the start of yout project. No need to rewrite all htmlspecialchars() entries globally.

I've spent several hours with both approaches. Variant 1 looks good especaially in combination with http://www.php.net/manual/en/function.rename-function.php as it allows to call original htmlspecialchars() with just altered default args. The code could be as follows:

<?php
rename_function
('htmlspecialchars', 'renamed_htmlspecialchars');
function
overriden_htmlspecialchars($string, $flags=NULL, $encoding='cp1251', $double_encode=true) {
$flags = $flags ? $flags : (ENT_COMPAT|ENT_HTML401);
return
renamed_htmlspecialchars($string, $flags, $encoding, $double_encode);
}
override_function('htmlspecialchars', '$string, $flags, $encoding, $double_encode', 'return overriden_htmlspecialchars($string, $flags, $encoding, $double_encode);');
?>

Unfortunatelly this didn't work for me properly - my site managed to call overriden function but not every time I reloaded the pages. Moreover other PHP sites crashed under my Apache server as they suddenly started blaming htmlspecialchars() was not defined. I suppose I had to spend more time to make it work thread/request/site/whatever-safe.

So I switched to runkit (variant 2). It worked for me, although even after trying runkit_function_rename()+runkit_function_add() I didn't managed to recall original htmlspecialchars() function. So as a quick solution I decided to call htmlentities() instead:

<?php
function overriden_htmlspecialchars($string, $flags=NULL, $encoding='UTF-8', $double_encode=true) {
$flags = $flags ? $flags : (ENT_COMPAT|ENT_HTML401);
$encoding = $encoding ? $encoding : 'cp1251';
return
htmlentities($string, $flags, $encoding, $double_encode);
}
runkit_function_redefine('htmlspecialchars', '$string, $flags, $encoding, $double_encode', 'return overriden_htmlspecialchars($string, $flags, $encoding, $double_encode);');
?>

You may be able to implement your more powerfull overriden function.
Good luck!
up
-11
Anonymous
19 years ago
function htmlspecialchars_array($arr = array()) {
$rs = array();
while(list($key,$val) = each($arr)) {
if(is_array($val)) {
$rs[$key] = htmlspecialchars_array($val);
}
else {
$rs[$key] = htmlspecialchars($val, ENT_QUOTES);
}
}
return $rs;
}
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