Re: [flexcoders] Get file type before upload

2009-01-17 Thread Paul Andrews
- Original Message - 
From: oneworld95 oneworl...@yahoo.com
To: flexcoders@yahoogroups.com
Sent: Friday, January 16, 2009 9:21 PM
Subject: [flexcoders] Get file type before upload


 Hi. Is there a way to discover the file type before you do an upload
 on a FileReference object? I know we can read the file extension but
 users can fiddle with that. Is there a way to read something on the
 file to ensure it's an image type of JPG, PNG, or GIF? Thanks.

Not as far as I know. If users mess up file extensions for upload, it's 
their lookout, surely?

Paul 



Re: [flexcoders] Get file type before upload

2009-01-17 Thread Guy Morton
Not really...if they upload a file with  .jpg extension that is  
actually a windows exe file containing malware it might be *your*  
lookout. Windows might be a bit smarter about this sort of thing these  
days (I hope) but I wouldn't rely on it.


I'd suggest you send it to the server and use a CGI to check it's type  
once it's there, and overwrite the file extension (or delete it) if  
need be. Both perl and PHP have modules for reading a file and  
returning it's actual type (File::MimeInfo::Magic and FileInfo  
respectively), as does Java.


File extensions are not a safe or adequate way to determine file type.  
Non-MS OSs don't use them to decide what data is inside a file and you  
shouldn't trust them either.


Guy


On 18/01/2009, at 12:10 AM, Paul Andrews wrote:


- Original Message -
From: oneworld95 oneworl...@yahoo.com
To: flexcoders@yahoogroups.com
Sent: Friday, January 16, 2009 9:21 PM
Subject: [flexcoders] Get file type before upload

 Hi. Is there a way to discover the file type before you do an upload
 on a FileReference object? I know we can read the file extension but
 users can fiddle with that. Is there a way to read something on the
 file to ensure it's an image type of JPG, PNG, or GIF? Thanks.

Not as far as I know. If users mess up file extensions for upload,  
it's

their lookout, surely?

Paul







[flexcoders] Get file type before upload

2009-01-16 Thread oneworld95
Hi. Is there a way to discover the file type before you do an upload
on a FileReference object? I know we can read the file extension but
users can fiddle with that. Is there a way to read something on the
file to ensure it's an image type of JPG, PNG, or GIF? Thanks.