php - UTF8 Encoding problem - With good examples

Question

I have the following character encoding issue, somehow I have managed to save data with different character encoding into my database (UTF8) The code and outputs below show 2 sample strings and how they output. 1 of them would need to be changed to UTF8 and the other already is.

How do/should I go about checking if I should encode the string or not? e.g. I need each string to be outputted correctly, so how do I check if it is already utf8 or whether it needs to be converted?

I am using PHP 5.2, mysql myisam tables:

CREATE TABLE IF NOT EXISTS `entities` (
  ....
  `title` varchar(255) NOT NULL
  ....
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

<?php
$text = $entity['Entity']['title'];
echo 'Original : ', $text."<br />";
echo 'UTF8 Encode : ', utf8_encode($text)."<br />";
echo 'UTF8 Decode : ', utf8_decode($text)."<br />";
echo 'TRANSLIT : ', iconv("ISO-8859-1", "UTF-8//TRANSLIT", $text)."<br />";
echo 'IGNORE TRANSLIT : ', iconv("ISO-8859-1", "UTF-8//IGNORE//TRANSLIT", $text)."<br />";
echo 'IGNORE   : ', iconv("ISO-8859-1", "UTF-8//IGNORE", $text)."<br />";
echo 'Plain    : ', iconv("ISO-8859-1", "UTF-8", $text)."<br />";
?>

Output 1:

Original : France Télécom
UTF8 Encode : France T??l??com
UTF8 Decode : France T?l?com
TRANSLIT : France T??l??com
IGNORE TRANSLIT : France T??l??com
IGNORE : France T??l??com
Plain : France T??l??com

Output 2:###

Original : Cond? Nast Publications
UTF8 Encode : Condé Nast Publications
UTF8 Decode : Cond?ast Publications
TRANSLIT : Condé Nast Publications
IGNORE TRANSLIT : Condé Nast Publications
IGNORE : Condé Nast Publications
Plain : Condé Nast Publications

Thanks for you time on this one. Character encoding and I don't get on very well!

UPDATE:

echo strlen($string)."|".strlen(utf8_encode($string))."|";
echo (strlen($string)!==strlen(utf8_encode($string))) ? $string : utf8_encode($string);
echo "<br />";
echo strlen($string)."|".strlen(utf8_decode($string))."|";
echo (strlen($string)!==strlen(utf8_decode($string))) ? $string : utf8_decode($string);
echo "<br />";

23|24|Cond? Nast Publications
23|21|Cond? Nast Publications

16|20|France Télécom
16|14|France Télécom

Answer 1

This may be a job for the mb_detect_encoding() function.

In my limited experience with it, it's not 100% reliable when used as a generic "encoding sniffer" - It checks for the presence of certain characters and byte values to make an educated guess - but in this narrow case (it'll need to distinguish just between UTF-8 and ISO-8859-1 ) it should work.

<?php
$text = $entity['Entity']['title'];

echo 'Original : ', $text."<br />";
$enc = mb_detect_encoding($text, "UTF-8,ISO-8859-1");

echo 'Detected encoding '.$enc."<br />";

echo 'Fixed result: '.iconv($enc, "UTF-8", $text)."<br />";

?>

you may get incorrect results for strings that do not contain special characters, but that is not a problem.