Double-byte character truncation

Double-byte character truncation, such as truncation of mixed Chinese and English text, etc.

 function substr($string, $length)
 {
 $i = 0;
 $j = 0;

 while($i < $length)
 {
 $char = ord($string[$ j]);
 if($char <= 0x7F)
 {
 $j++;
 }
 else
 {
 $j += 2;
 }
 $i++;
 }
 return substr($string,0, $j);
 }