showLastLength as a command-line option?

[Jonathan Kulp]

Would it be possible technically to specify the showLastLength value 
when invoking lilypond instead of putting it in the .ly file?  Something 
like

lilypond --lastlength=20 filename.ly

to process only the last 20 bars?  The problem with this particular 
example (and maybe with trying to do this at all) is that it doesn't 
specify the length of each bar, but it could be set to a default of R1 I 
guess.

My original idea was to try to put this into a shell script, but I don't 
have the slightest idea how to go about it.  I'm not a programmer but am 
starting to get some basic scripting chops and I'd like to learn how to 
customize my lilypond experience a bit further.  This is a feature I'd 
LOVE to have.  I'd appreciate any advice or suggestions.

Jon
--
Jonathan Kulp
http://www.jonathankulp.com