I have come across a new problem with my program, in which the pattern I have provided it only opens and read's .txt files I assume this is because this is the first on the list.

PHP Code:

function opening($file)
{

$pattern = "(\.txt$)| (\.php$)| (\.html$)| (\.htm$)"; // pattern to match
if(eregi($pattern, $file)){
 $file_handle = fopen($file, "r");
 $contents = file($file);
 while (!feof($file_handle)){
  $data = fgets($file_handle);
  $words = explode(' ' , $data);
  $duplicates = array_unique($words);
  sort($duplicates);
  if(is_bool(strpos($stoplist, '$duplicates[i]')))
  {
  foreach($duplicates as $word)
  {
   $word = serialize($word);
   $sql = "INSERT INTO webdata VALUES('$file','$word')";
   if (mysql_query($sql))
   {
    print "successful <p>";
   }
  }
  }

}
}
else {
echo "Cant open that file type <p>"; }
} 


How can I fix this so it opens all the provided file extensions?

I usually use something like this (just easier from my perspective, so no other reason why):

PHP Code:

$allowed_extensions = array('txt'=>true, 
                            'php'=>true,
                            'htm'=>true,
                            'html'=>true);
$path_parts = pathinfo($file);
if(isset($allowed_extensions[$path_parts['extension']])){ 


You have spaces in your regex. it is looking for files that end in " .php" rather than ".php"

Remove the spaces and it should work