(PHP 4 >= 4.0.6, PHP 5)
mb_strimwidth — Get truncated string with specified width
$str
   , int $start
   , int $width
   [, string $trimmarker = ""
   [, string $encoding = mb_internal_encoding()
  ]] )
   Truncates string str to specified width. 
  
strThe string being decoded.
startThe start position offset. Number of characters from the beginning of string. (First character is 0)
widthThe width of the desired trim.
trimmarkerA string that is added to the end of string when string is truncated.
encodingIl parametro encoding 
è la codifica dei caratteri. Se è omesso, verrà utilizzata la 
codifica interna.
   The truncated string. If trimmarker is set,
   trimmarker is appended to the return value.
  
Example #1 mb_strimwidth() example
<?php
echo mb_strimwidth("Hello World", 0, 10, "...");
// outputs Hello W...
?>