I'm writing function that returns document in utf-8 by default, by if you provide special parameter it will return content in utf-16le. I started to write unit test for this function and what I don't understand is how to check if encoding is "utf-8" or "utf-16le". I've tried mb_detect_encoding
but it returns false
even in this code snippet:
$utf16Doc = mb_convert_encoding($doc, "utf-16le", "utf8");
$test = mb_detect_encoding($utf16Doc, "utf-16le");
var_dump($test);
Appreciate any ideas how to check in test that encoding is utf-16le and not utf-8.
A simple way to detect UTF-8/16/32 of file by its BOM (not work with string or file without BOM)
<?php
// Unicode BOM is U+FEFF, but after encoded, it will look like this.
define ('UTF32_BIG_ENDIAN_BOM' , chr(0x00) . chr(0x00) . chr(0xFE) . chr(0xFF));
define ('UTF32_LITTLE_ENDIAN_BOM', chr(0xFF) . chr(0xFE) . chr(0x00) . chr(0x00));
define ('UTF16_BIG_ENDIAN_BOM' , chr(0xFE) . chr(0xFF));
define ('UTF16_LITTLE_ENDIAN_BOM', chr(0xFF) . chr(0xFE));
define ('UTF8_BOM' , chr(0xEF) . chr(0xBB) . chr(0xBF));
function detect_utf_encoding($filename) {
$text = file_get_contents($filename);
$first2 = substr($text, 0, 2);
$first3 = substr($text, 0, 3);
$first4 = substr($text, 0, 3);
if ($first3 == UTF8_BOM) return 'UTF-8';
elseif ($first4 == UTF32_BIG_ENDIAN_BOM) return 'UTF-32BE';
elseif ($first4 == UTF32_LITTLE_ENDIAN_BOM) return 'UTF-32LE';
elseif ($first2 == UTF16_BIG_ENDIAN_BOM) return 'UTF-16BE';
elseif ($first2 == UTF16_LITTLE_ENDIAN_BOM) return 'UTF-16LE';
}
?>
So now you can try like this,
$utf16Doc = mb_convert_encoding($doc, "utf-16le", "utf8");
$test = detect_utf_encoding($utf16Doc);
var_dump($test);
Clearly Stated : This is not my own written answer. I just found it on php.net official site under mb_detect_encoding
by a user http://php.net/manual/en/function.mb-detect-encoding.php#68607 . Hope this will help you somehow
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