Re: Magic is useless!

[James Henstridge <james daa com au>]

Maciej Stachowiak wrote:

> > Most major file formats already have a detectable magic byte
> > signaturate, though some of the now prospering "human readable"
> > formats using XML or whatever are a thorn in the side (particularly
> > if they are compressed, grr). But this would be a good complement.
>
> XML is reasonably OK, actually, since a proper XML document has a DTD
> declaration at the top that you can look for. The main problem is
> compressed files and archives, since you need to either look inside
> the compression/archiving, or allow suffixes to take precedence for
> those types (returning to the bad old suffix-based world for those
> kinds of files). We really should come up with a solution to this in
> gnome-vfs, since it is a frequent user complaint.
Is it just me, or do file extensions and mime types stored in the 
filesystem as metadata seem equivalent?  Both move with the file in the 
filesystem (provided the app/user doesn't decide to change them), and 
won't be available if just reading from a bytestream (in which case you 
will need to get the information some other way, such as file magic).

The benefit of file extensions is that they are maintained over almost 
every file system type.

James.

--
Email: james daa com au
WWW:   http://www.daa.com.au/~james/