Can't delete files uploaded via website

[scavok]

This is the first time I've attempted to make a script to upload files. For some reason, I can't delete the files after I upload them. I'm assuming the problem is regarding chmod settings (I'm probably wrong).

When I try to delete one of the files I uploaded by FTP, it says permission denied. When I try to modify the chmod settings, it gives me the error, "Could not change perms on exam2_wans.pdf: Bad file descriptor"

Any ideas?

<?PHP
  include ('includes/header.php');
  if ($submit) {
	$query="SELECT volume FROM volumes";
    $result=mysql_query($query);
    $num=mysql_numrows($result);

$i=0;
$lastvol=0;
while ($i < $num) {
  $volume=mysql_result($result,$i);

  if ($volume > $maxvol)
  {
    $lastvol=$volume;
  }

  $newvol=$lastvol+1;

  $i++;
}

mkdir("/home/andyk/public_html/pem/volumes/" . $newvol, 0777);
$pdfname=uploader(pdf,$newvol);

$query="INSERT INTO volumes (volume,volumetitle,volumepdf,date) VALUES ('$newvol', '$title', '$pdfname', '$date')";
$result=mysql_query($query);
  }

  include ('includes/newvolumeform.php');

  function uploader($fieldname,$folder) {
	$safe_filename = clean_filename($_FILES[$fieldname]['name']);
	$full_path = "/home/andyk/public_html/pem/volumes/".$folder."/".$safe_filename;
	$working_path = "/pem/volumes/".$folder."/".$safe_filename;

if (move_uploaded_file($_FILES[$fieldname]['tmp_name'], $full_path)) {
  print $safe_filename.' successfully uploaded as '.$working_path;
  //return working path
  return $working_path;
} else {
  return false;
}
  }

  function clean_filename($filename) {
	$filename = str_replace('/','',$filename);
	$filename = str_replace(' ','_',$filename);
	$filename = str_replace('?','',$filename);
	$filename = str_replace('!','',$filename);
	$filename = str_replace('\'','',$filename);
	$filename = str_replace('"','',$filename);
	$filename = strtolower($filename);
	return $filename;
  }

  include ('includes/footer.php');
?>

[bastien]

Try changing permissions on the file's folder instead...That is what really on controls deleting of files

[Sxooter]

I don't see where, in your code, you're deleting anything. how are you trying to delete this file?

[madwormer2]

Via FTP.

Try doing it with a PHP script, see if that works?

unlink('file.pdf');

[Sxooter]

yeah, now I see that comment. was a bit late when I wrote that response.

What happens is that php code is executed as a different user than via ftp. so, you have to delete it by that same user.