Smart character limit functions for PHP

gistfile1.php

// Intelligently truncate a string to a certain number of characters.
// Each uppercase or wider-than-normal character reduces the final length.
 
function truncate($string, $length, $ellipsis = true) {
  // Count all the uppercase and other wider-than-normal characters
  $wide = strlen(preg_replace('/[^A-Z0-9_@#%$&]/', '', $string));
  
  // Reduce the length accordingly
  $length = round($length - $wide * 0.2);
  
  // Condense all entities to one character
  $clean_string = preg_replace('/&[^;]+;/', '-', $string);
  if (strlen($clean_string) <= $length) return $string;
  
  // Use the difference to determine where to clip the string
  $difference = $length - strlen($clean_string);
  $result = substr($string, 0, $difference);
  
  if ($result != $string and $ellipsis) {
    $result = add_ellipsis($result);
  }
  
  return $result;
}

// Replaces the last 3 characters of a string with "...". If there is a space
// followed by three letters or less at the end of the string, those will
// also be removed, along with any extra white space.

function add_ellipsis($string) {
  $string = substr($string, 0, strlen($string) - 3);
  return trim(preg_replace('/ .{1,3}$/', '', $string)) . '...';
}

// Truncates a string and guarantees it will display at a maximum number
// of lines (spaces are inserted if necessary so that the string will wrap).
// Uses the truncate() function so uppercase or wider-than-normal characters
// actually make the final string shorter, for layout reasons.

function truncate_lines($string, $line_length, $lines, $ellipsis = true) {
  $result = '';
  $spaces_added = 0;
  
  // Divide up the string into lines
  for ($i=0;$i<$lines;$i++) {
    if (! $next_start) {
      $start = $i * $line_length;
    } else {
      $start = $next_start;
    }
    
    $line = substr($string, $start, $line_length + 1);
    
    // Truncate the line by the appropriate length
    $old_line = $line;
    $line = truncate($line, $line_length, false);
    $difference = strlen($old_line) - strlen($line);
    $next_start = (($i + 1) * $line_length) - $difference + 1;
    
    // If there are no line breaks in this line at all
    if (strlen($line) < strlen($string) and ! strstr($line, ' ')) {
      // Add a space to it, keep track of how many spaces are added
      $line .= ' ';
      $spaces_added ++;
    }
    
    $result .= $line;
  }
  
  $result = substr($result, 0, strlen($result) - $spaces_added);
  
  if ($result != $string and $ellipsis) {
    $result = add_ellipsis($result);
  }
  
  return $result;
}

Thanks