$re = '/<(\/?[-.0-9_a-z\xb7\xc0-\xd6\xd8-\xf6\xf8-\x{37d}\x{37f}-\x{1fff}\x{200c}-\x{200d}\x{203f}-\x{2040}\x{2070}-\x{218f}\x{2c00}-\x{2fef}\x{3001}-\x{d7ff}\x{f900}-\x{fdcf}\x{fdf0}-\x{fffd}\x{10000}-\x{effff}]*)\s*([^>]*)>/mu';
$str = '<emotion-😍>.
<math-α>
<test.attr="5">
<what value=false>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php