PHP - Convert from UTF-8 to Unicode hex

Question

Is there an easy way to convert a string in UTF-8 to its unicode? What i'm basically trying to do is to transform 'è' to '00E8'.

Answer 1

You can use json_encode to do that...

$str = "è";
$str = json_encode($str);
print $str;

This will print \u00e8. You can str_replace to remove the \u if you want. You can use strtoupper if you want an E instead of an e.

Answer 2

Here's a little something that I modified from a debugging class of mine

/**
 * Display utf && non-printable characters as hex
 *
 * @param string  $str     string containing binary
 * @param boolean $htmlout add html markup?
 *
 * @return string
 */
public function strInspect($str)
{
    $this->htmlout = $htmlout;
    $regex = <<<EOD
/
( [\x01-\x7F] )                 # single-byte sequences   0xxxxxxx  (ascii 0 - 127)
| (
  (?: [\xC0-\xDF][\x80-\xBF]    # double-byte sequences   110xxxxx 10xxxxxx
    | [\xE0-\xEF][\x80-\xBF]{2} # triple-byte sequences   1110xxxx 10xxxxxx * 2
    | [\xF0-\xF7][\x80-\xBF]{3} # quadruple-byte sequence 11110xxx 10xxxxxx * 3
  ){1,100}                      # ...one or more times
)
| ( [\x80-\xBF] )               # invalid byte in range 10000000 - 10111111   128 - 191
| ( [\xC0-\xFF] )               # invalid byte in range 11000000 - 11111111   192 - 255
| (.)                           # null (including x00 in the regex = fail)
/x
EOD;
    $str_orig = $str;
    $strlen = strlen($str);
    $str = preg_replace_callback($regex, 'strInspectCallback', $str);
    return $str;
}

/**
 * Callback used by strInspect's preg_replace_callback
 *
 * @param array $matches matches
 *
 * @return string
 */
protected function strInspectCallback($matches)
{
    $showHex = false;
    if ($matches[1] !== '') {
        // single byte sequence (may contain control char)
        $str = $matches[1];
        if (ord($str) < 32 || ord($str) == 127) {
            $showHex = true;
            if (in_array($str, array("\t","\n","\r"))) {
                $showHex = false;
            }
        }
    } elseif ($matches[2] !== '') {
        // Valid byte sequence. return unmodified.
        $str = $matches[2];
        $sequences = array(
            "\xef\xbb\xbf", // BOM
            "\xc2\xa0",     // no-break space
            // "\xE2\x80\x89", // thin space
            // "\xE2\x80\xAF", // narrow no-break space
            "\xEF\xBF\xBD",     // "Replacement Character"
        );
        foreach ($sequences as $seq) {
            if ($str === $seq) {
                $showHex = true;
                break;
            }
        }
    } elseif ($matches[3] !== '' || $matches[4] !== '') {
        // Invalid byte
        $str = $matches[3] != ''
            ? $matches[3]
            : $matches[4];
        $showHex = true;
    } else {
        // null char
        $str = $matches[5];
        $showHex = true;
    }
    if ($showHex) {
        $chars = str_split($str);
        foreach ($chars as $i => $c) {
            $chars[$i] = '\x'.bin2hex($c);
        }
        $str = implode('', $chars);
    }
    return $str;
}