On Sat, 2004-06-05 at 02:19, Bryce Harrington wrote:
On Fri, 4 Jun 2004, Jeremy C. Reed wrote:
I can submit it. But I don't know if it is possible to create a magic(5) for SVG since they can start so many different ways.
Hmm, good point, though isn't XML by definition supposed to contain indicators of what *type* of XML it is?
Not really. Doctypes used to be sort of helpful, but nowadays with XML namespaces you can have a mixture of namespaces/grammars/schemas.
Think about e.g. SVG-in-XHTML for example. Or XHTML-in-SVG. Or worse, MathML-in-XHTML-in-SVG.
Needless to say this is also giving the MIME folks fits. :P
Does anyone know how to configure magic so the offset is not forced? (For example "<!DOCTYPE svg" could be at 141 position or could be at some other position. Or the "<svg" marker may be at some random place.
I'm also CCing to the Inkscape mailing list in case someone there can answer it.
Just looking for <!DOCTYPE svg isn't really robust -- you'd need match on the appropriate public identifier ("-//W3C//etc..."). That's assuming there is a DOCTYPE declaration.
[ Except when we're writing "pure" SVG, we really shouldn't add a DOCTYPE declaration unless we're prepared to include a complete external DTD subset thingy that covers all the additional elements/attributes in the document (whether introduced by Inkscape or not, which introduces the problem of needing to do Examplotron-style schema inference). ]
Looking for namespace decls is even trickier; you can't assume that the SVG namespace is the default namespace, or that its prefix will be 'svg' (it's not required to be).
Strictly speaking, even the initial <?xml version="1.0"?> declaration is optional (at least in the 1.0 spec -- this is widely viewed as having been a bad idea, in retrospect)
The short answer is that it is far, far outside the capabilities of magic(1) to detect a specific XML application, and there's even a great deal of question about what the appropriate MIME types would be in nontrivial cases.
-mental