Completion... but only for the extension part

[Thomas Lauer <thomas.lauer@xxxxxxxxxx>]

Sorry if this is in the Fine Manual but I couldn't find it (and googling
also brought no great enlightenment).

I have directories with many files in them which all have rather long
extensions (12+ chars). There can be quite a few separate extensions,
say "*.winter-music" or "*.spanish-photos"... you get the idea.

So, often I want to complete filenames as normal but sometimes I want to
limit completion to files with just one specific extension, say
"*.indonesian-videos". So... I'd like to type "*.indo" and then press
<whatever> to get "*.indonesian-videos" which in its turn will complete
only those files. The problem is the <whatever> bit... or rather a
function that does that and can be bound to <whatever>. Do I have to
write such a function or is there something in the completion system
that will do this OOTB?

Thanks for looking into that.

T