Re: Magic MIME

[Stefan Monnier <monnier@iro.umontreal.ca>]

> Yes, I remember what a mess was the recognition of image files.  But I think
> that for other binary formats this could by simplified.  If, say, a file
> doesn't start with the "0x8080ffff 0x0000081a" signature there is no sense
> to try treating it as an arc archive even if it has the .arc extension.

Agreed.  But just because a file starts with "0x8080ffff 0x0000081a"
shouldn't be enough of a reason to treat it as an arc archive: we need to
look at the filename as well.

> IIRC, the decision for the image file extensions taking precedence over
> the image file content was based solely on the security holes that some
> image libraries reportedly have.

I don't think so.  I do remember that it was decided not to introduce
the two-sided (file-name and file-contents) method so close to
the release.  So now would be a better time.

We could associate "\\.arc\\'" with '(lisp-arc-mode archive-mode)
and associate "0x8080ffff 0x0000081a" to archive-mode (and some other
pseudo-magic thingy for Arc-the-language).


        Stefan