Compile twice with different includes

[Urs Liska]

Hi list,

maybe it's an academic question, but maybe it also triggers the 
curiosity of some Scheme-hackers ;-)

Is it possible to write something (probably a Scheme function) that lets 
LilyPond compile a file twice with a different file included or a 
different command line option?
Or is it possible from within a document to launch a second LilyPond 
instance with an arbitrary command line option set?

The background is: I want to create a scenario where I can compile two 
different pdf files in one run. The two files should have a different 
first-page-number and a different filename suffix. I would like to have 
two versions of a score starting on odd and even pages. (Afterwards I 
want to include the appropriate file in a LaTeX document, depending on 
the page in the document.)

I can imagine doing this with two layout include files (like 
'start-odd.ily' and 'start-even.ily') or with a function that directly 
writes the right commands depending on command line options (like 
'-dstartodd' or 'dstarteven').

So maybe the easiest way would be to have a function that triggers two 
separate lilypond runs on the same file, providing different command 
line options. I'd then have a main .ly file as usual that includes one 
of two style sheets depending on the presence of command line options, 
but I would explicitely run lilypond on a 'master' file that doesn't 
actually contain music but only controls the build process.

Any ideas?

Best
Urs