[Mediawiki-api] How to use &generator and &export commands ?

[Colonna Francois]

Hello

To export 100 pages starting at "D" I tried to use the following
command :

api.php?action=query&generator=allpages&gapfrom=D&gaplimit=100&export

this has the same result as 

api.php?action=query&generator=allpages&gapfrom=D&gaplimit=100

How can I make the export command work ? 
i.e. get an Xml file similar to that obtained with Special:Export ?

What kind of name this exported file is expected to have ?

Thanks
Francois Colonna