Convert (doublebyte) string to Hex

Question

Let's say I have the word "Russian" written in Cyrillic. This is would be the quivalent of the following in Hex:

&#1056;&#1091;&#1089;&#1089;&#1082;&#1080;&#1081;

My question is: how do I write a function which will go from "Russian" in Cyrillic to it's hex value as above? Could this same function work also for singel byte characters?

Are you looking for [`htmlspecialchars()`](http://php.net/manual/en/function.htmlspecialchars.php)? — Brad Christie, Aug 10 '11 at 17:05
That won't convert every letter, only applicable special characters. — AlienWebguy, Aug 10 '11 at 17:06
@brad, @alien: use `htmlentities()` which should convert most characters — knittl, Aug 10 '11 at 17:12
Doesn't work with cryllic: `echo htmlentities('русский'); // outputs Ñ€ÑƒÑÑÐºÐ¸Ð¹` — AlienWebguy, Aug 10 '11 at 17:14
`htmlentities` converts nothing of those, [use `mb_encode_numericentity`](http://stackoverflow.com/questions/7014791/convert-doublebyte-string-to-hex/7015137#7015137). — hakre, Aug 10 '11 at 17:34

score 5 · Accepted Answer · answered Aug 10 '11 at 17:28

The 〹 thingies are called HTML Entities. In PHP there is a function that can create these: mb_encode_numericentity^Docs, it's part of the Multibyte String extension (Demo):

$cyrillic = 'русский';

$encoding = 'UTF-8';
$convmap = array(0, 0xffff, 0, 0xffff);
$encoded = mb_encode_numericentity($cyrillic, $convmap, $encoding);

echo $encoded; # &#1088;&#1091;&#1089;&#1089;&#1082;&#1080;&#1081;

However: You need to know the encoding of your Cyrillic string. In this case I've chosen UTF-8, depending on it you need to modify the $encoding parameter of the function and the $convmap array.

AlienWebguy · Answer 2 · 2011-08-10T17:11:28.810

2

Your provided example isn't hex, but if you want to convert to hex, try this:

function strToHex($string)
{
    $hex='';
    for ($i=0; $i < strlen($string); $i++)
    {
        $hex .= dechex(ord($string[$i]));
    }
    return $hex;
}

function hexToStr($hex)
{
    $string='';
    for ($i=0; $i < strlen($hex)-1; $i+=2)
    {
        $string .= chr(hexdec($hex[$i].$hex[$i+1]));
    }
    return $string;
}

echo strToHex('русский'); // d180d183d181d181d0bad0b8d0b9

edited Aug 10 '11 at 17:11

answered Aug 10 '11 at 17:05

AlienWebguy

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One note - control characters (such as \n) cause issue, so you'll need to 0-pad them by changing the " dechex(ord($string[$i])) " bit to " str_pad(dechex(ord($string[$i])), 2, "0", STR_PAD_LEFT) " in the strToHex() call. But a fantastic answer overall - thanks _very_ much for this :-) – Dave Carpeneto Jul 06 '16 at 13:25

Convert (doublebyte) string to Hex

2 Answers2

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