[vorbis] Why the commotion about file extensions?

[Jens Prüfer]

Am Montag, 14. Juli 2003 14:29 schrieb Nicolas Romantzoff:
> Hi,

Hello,

> I think you just misunderstanding completely why file-types are so
> important...

Frankly, I think I don't :) 

Far from it. I just want the identification of file types to be as accurate as 
possible. 

> When developping an advanced interface system, the user simply doesn't
> want to know which program is able to print that file, view it, or edit
> it... He just wants to print it, or view it, or edit it, no matter how
> the system is setup.

Right. As an aside, I wonder how you tell the system by just double clicking 
on a file that you want to view, edit, print or do whatever with it. That's 
what causes a lot of grief for windows users.

> There are not so many ways of doing this:
> - Parsing the file content for magic things in a big big database =>
> enforces ALL files to contain magic signatures (but how would you see
> the difference for those formats not implementing magic signatures, like
> RAW, TXT, or AU). This would force the system to launch a big bunch of
> processes just to determine the type of the file.

Actually on Linux (Unix) Systems, you have the "file" command, which does 
exactly that. Since I do not click on files in "100 clicks per second" speed, 
I don't see any performance problems whatsoever. That method is very acurate 
and works cross-platform, since it does not rely on any additional resource 
data (Mac) and sure as hell not on some arbitrary three letter extensions.

Of course it is not 100% accurate, but a lot more secure. Tampering with file 
headers usually renders the file unusable, since the operating system or 
application needs the information stored there to "recognize" the file and 
initialize accordingly. If the "file" tool does not recognize the file as 
"executable ELF binary", there is a good chance the OS won't either.

> Sincerely, I hate Microsoft Windows (though with XP it became pretty
> good), but the the last solution is the fastest and the most conveniant,
> though surely not the more secure since anyone can change the name of
> the file (note that this is the reason why by default on windows you
> simply do NOT see the extension, and you cannot change it without a big
> "warning").

Which again is one of the reason why viruses and other malicious code is so 
easy to deploy on Windows systems (sending harmless.txt.exe files).

> BTW, since im developping for all three major systems (with no
> particular preference though Windows is clearly the only profitable
> target)

OK, this is not the place for a general Linux vs. Windows discussion, but I 
could not disagree more clearly on that last remark.

Maybe the main difference between Linux and Windows users is that Linux people  
generally prefer security over speed. 

Cheers

Jens
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