Akii Snow

<?php
// Returns true if $string is valid UTF-8 and false otherwise.
function is_utf8($string) {
// From http://w3.org/International/questions/qa-forms-utf-8.html
return preg_match('%^(?:
[\x09\x0A\x0D\x20-\x7E] # ASCII
| [\xC2-\xDF][\x80-\xBF] # non-overlong 2-byte
| \xE0[\xA0-\xBF][\x80-\xBF] # excluding overlongs
| [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2} # straight 3-byte
| \xED[\x80-\x9F][\x80-\xBF] # excluding surrogates
| \xF0[\x90-\xBF][\x80-\xBF]{2} # planes 1-3
| [\xF1-\xF3][\x80-\xBF]{3} # planes 4-15
| \xF4[\x80-\x8F][\x80-\xBF]{2} # plane 16
)*$%xs', $string);
} // function is_utf8
?>

$field =~
  m/\A(
     [\x09\x0A\x0D\x20-\x7E]            # ASCII
   | [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
   |  \xE0[\xA0-\xBF][\x80-\xBF]        # excluding overlongs
   | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
   |  \xED[\x80-\x9F][\x80-\xBF]        # excluding surrogates
   |  \xF0[\x90-\xBF][\x80-\xBF]{2}     # planes 1-3
   | [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15
   |  \xF4[\x80-\x8F][\x80-\xBF]{2}     # plane 16
  )*\z/x;

PHP&MYSQL