Sanitize filename and extensions

Jamie,

finally back working on drupal code again (after a few months away) and started playing with your latest fileshare code. Looks like you've done a lot with it, great work!

Any ways, uploading some files with long filenames I noticed that the extensions were being lost (anything after the 50 character limit was cut). Additionally, a file called "filename.psd" would end up as "filenamepsd" because the module removes the "." characters as well, which creates problems after downloading if the OS can't figure out what filetype to use without an extension.

So I updated the _sanitize_filename function to try handle those situations. Not nearly as short and pretty as what you had, but it seems to do the trick. By the way, is there any particular reason for the 50 character limit? Could I extend that limit without messing up some check you had in mind?

Patrick

/**
 * Returns a filename based on the $name paramater that has been
 * striped of special characters, it's spaces changed to underscores,
 * and shortened to 50 characters... but keeping it's extension
 * PD: Updated to keep extensions, based on code by timdw at
 * http://forums.codecharge.com/posts.php?post_id=75694
 */
function _sanitize_filename($name) {
  $special_chars = array ("#","$","%","^","&","*","!","~","‘","\"","’","'","=","?","/","[","]","(",")","|","<",">",";","\\",",",".");
  $name = preg_replace("/^[.]*/","",$name); // remove leading dots
  $name = preg_replace("/[.]*$/","",$name); // remove trailing dots
  
  $lastdotpos=strrpos($name, "."); // save last dot position
  
  $name = str_replace($special_chars, "", $name);  // remove special characters
  
  $name = str_replace(' ','_',$name); // replace spaces with _
  
  $afterdot = "";
  if ($lastdotpos !== false) { // Split into name and extension, if any.
	if ($lastdotpos < (strlen($name) - 1))
		$afterdot = substr($name, $lastdotpos);
    
	$extensionlen = strlen($afterdot);
	
    if ($lastdotpos < (50 - $extensionlen) )
		$beforedot = substr($name, 0, $lastdotpos);
	else
		$beforedot = substr($name, 0, (50 - $extensionlen));
  }
  else   // no extension
   $beforedot = substr($name,0,50);
 
  
  if ($afterdot)
	$name = $beforedot . "." . $afterdot;
  else
	$name = $beforedot;
  
  return $name;

}