english/libraries/joomla/utilities/string.php
/**
	 * Tests whether a string complies as UTF-8. This will be much
	 * faster than utf8_is_valid but will pass five and six octet
	 * UTF-8 sequences, which are not supported by Unicode and
	 * so cannot be displayed correctly in a browser. In other words
	 * it is not as strict as utf8_is_valid but it's faster. If you use
	 * it to validate user input, you place yourself at the risk that
	 * attackers will be able to inject 5 and 6 byte sequences (which
	 * may or may not be a significant risk, depending on what you are
	 * are doing)
	 *
	 * @param   string  $str  UTF-8 string to check
	 *
	 * @return  boolean  TRUE if string is valid UTF-8
	 *
	 * @see     valid
	 * @see     http://www.php.net/manual/en/reference.pcre.pattern.modifiers.php#54805
	 * @since   11.1
	 */
Tests whether a string complies as UTF-8. This will be much
faster than utf8_is_valid but will pass five and six octet
UTF-8 sequences, which are not supported by Unicode and
so cannot be displayed correctly in a browser. In other words
it is not as strict as utf8_is_valid but it's faster. If you use
it to validate user input, you place yourself at the risk that
attackers will be able to inject 5 and 6 byte sequences (which
may or may not be a significant risk, depending on what you are
are doing)

@param   string  $str  UTF-8 string to check

@return  boolean  TRUE if string is valid UTF-8


Tests whether a string complies as UTF - 8 . This will be much faster than utf8_is_valid but will pass five and six octet UTF - 8 sequences which are not supported by Unicode and so cannot be displayed correctly in a browser . In other words it is not as strict as utf8_is_valid but it ' s faster . If you use it to validate user input you place yourself at the risk that attackers will be able to inject 5 and 6 byte sequences ( which may or may not be a significant risk depending on what you are are doing ) @param string $str UTF - 8 string to check @return boolean TRUE if string is valid UTF - 8
public static function compliant($str)
	{
		if (strlen($str) == 0) {
			return TRUE;
		}
		return (preg_match('/^.{1}/us',$str,$ar) == 1);
	}
public static function compliant ( $ str ) { if ( strlen ( $ str ) == 0 ) { return TRUE ; } return ( preg_match ( '/^.{1}/us' , $ str , $ ar ) == 1 ) ; }
Tests whether a string complies as UTF-8.
Tests whether a string complies as UTF - 8 .
// If even just the first character can be matched, when the /u // modifier is used, then it's valid UTF-8. If the UTF-8 is somehow // invalid, nothing at all will match, even if the string contains // some valid sequences