Generate fake text with optional paragraphs and html

Lorem.php

<?php
function lorem($length = 5, $paragraphs = false, $html = false)
{
  $corpus = array('ad', 'adipisicing', 'aliqua', 'aliquip', 'amet', 'anim', 'aute', 'cillum', 'commodo', 'consectetur', 'consequat', 'culpa', 'cupidatat', 'deserunt', 'do', 'dolor', 'dolore', 'duis', 'ea', 'eiusmod', 'elit', 'enim', 'esse', 'est', 'et', 'eu', 'ex', 'excepteur', 'exercitation', 'fugiat', 'id', 'in', 'incididunt', 'ipsum', 'irure', 'labore', 'laboris', 'laborum', 'lorem', 'magna', 'minim', 'mollit', 'nisi', 'non', 'nostrud', 'nulla', 'occaecat', 'officia', 'pariatur', 'proident', 'qui', 'quis', 'reprehenderit', 'sed', 'sint', 'sit', 'sunt', 'tempor', 'ullamco', 'ut', 'velit', 'veniam', 'voluptate');

  // If HTML tag given, figure out the closing tag
  $open_tag = $closing_tag = false;
  
  if ($html)
  {
    $open_tag = $html;
    if (preg_match('/^<([a-z]+)/i', $open_tag, $matches))
    {
      $closing_tag = sprintf('</%s>', $matches[1]);
    } else {
      throw new Exception('Couldn\'t derive closing tag. Bad input?');
    }
  }


  // Expand corpus size to fit requested length
  while (count($corpus) < $length)
  {
    $corpus = array_merge($corpus, $corpus);
  }
  
  if ($length > 1)
  {
    $keys = array_rand($corpus, $length - 1);
    $out = array('Lorem');
    
    foreach($keys as $idx => $k)
    {
      if (mt_rand(1,15) == 1)
      {
        $out[] = '. '.ucfirst($corpus[$k]);
      }
      elseif (mt_rand(1,12) == 1)
      {
        $out[] = ', '.$corpus[$k];
      } else {
        $out[] = $corpus[$k];
      }
    }
    
    $out = ($html ? $open_tag : '') . str_replace(array(' .', ' ,'), array('.', ','), join($out, ' ').'.') . ($html ? $closing_tag : '');
    
    if ($paragraphs) {
      $out = preg_replace_callback('/\. /', function($matches) use ($html, $open_tag, $closing_tag){
        static $dotcount = 0;
        static $paralength = null;
        
        if (!$paralength)
        {
          $paralength = mt_rand(5,7);
        }
        
        if ((++$dotcount % $paralength) == 0)
        {
          return $matches[0].($html ? $closing_tag.PHP_EOL.PHP_EOL.$open_tag : PHP_EOL.PHP_EOL);
        } 
        else
        {
          return $matches[0];
        }
        
      }, $out);
      
      
    }
    
    return $out;
    
  } 
  else
  {
    return $html ? sprintf('%sLorem%s', $open_tag, $closing_tag) : 'Lorem.';
  }
  
}

/* Self-test */
if (basename($_SERVER['SCRIPT_NAME']) == basename(__FILE__))
{
  $length = isset($_SERVER['argv'][1]) ? intval($_SERVER['argv'][1]) : 40;
  echo lorem($length, true, '<p class="lorem">').PHP_EOL;
}