Re: Checking file type when uploading

On Sat, 2010-09-18 at 11:21 +0200, Peter Lind wrote: > On 17 September 2010 23:25, Jim Lucas <lists@cmsws.com> wrote: > > Catherine Madsen wrote: > >> Hi! > >> > >> I have created a form following the PHP manual to upload files and need > >> to restrict the upload to only PDF. How do I check the file type > >> ($_FILES['userfile']['type']?) and where: on the form page or on > >> the > >> validation page? I want to be able to tell the users that their file > >> doesn't have the right format. Thank you very much for your help! > >> > > You need to use something like http://www.fpdf.org/ to try and > actually open the uploaded file - anyone can fake an extension. > > Regards > Peter > > -- > <hype> > WWW: http://plphp.dk / > http://plind.dk > LinkedIn: http://www.linkedin.com/in/plind > BeWelcome/Couchsurfing: Fake51 > Twitter: http://twitter.com/kafe15 > </hype> > An exec() call to the 'file' command (assuming you're on a Linux server) should give you back the correct file type as well. I just tested mine with file-5.03 on a mis-named file and it correctly detected it. That's not to say a carefully crafted file couldn't trick it, but it might be good as a general checker where it would be a lot of hassle trying to check every single file type by opening it up. Thanks, Ash http://www.ashleysheridan.co.uk