note 68607 added to function.mb-detect-encoding

Based upon that snippet below using preg_match() I needed something faster and less specific. That function works and is brilliant but it scans the entire strings and checks that it conforms to UTF-8. I wanted something purely to check if a string contains UTF-8 characters so that I could switch character encoding from iso-8859-1 to utf-8. I modified the pattern to only look for non-ascii multibyte sequences in the UTF-8 range and also to stop once it finds at least one multibytes string. This is quite a lot faster. <?php function detectUTF8($string) { return preg_match('%(?: [\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); } ?> ---- Server IP: 85.116.0.130 Probable Submitter: 213.205.138.154 ---- X-Spam-Status: No, hits=3.1 required=5.0 tests=DATE_MISSING,FROM_NO_LOWER autolearn=no version=2.64 ---- Manual Page -- http://www.php.net/manual/en/function.mb-detect-encoding.php Edit -- https://master.php.net/note/edit/68607 Del: integrated -- https://master.php.net/note/delete/68607/integrated Del: useless -- https://master.php.net/note/delete/68607/useless Del: bad code -- https://master.php.net/note/delete/68607/bad+code Del: spam -- https://master.php.net/note/delete/68607/spam Del: non-english -- https://master.php.net/note/delete/68607/non-english Del: in docs -- https://master.php.net/note/delete/68607/in+docs Del: other reasons-- https://master.php.net/note/delete/68607 Reject -- https://master.php.net/note/reject/68607 Search -- https://master.php.net/manage/user-notes.php