Re: init.ly, what does it do?

[Simon Albrecht]

On 08.01.2017 20:33, Br. Samuel Springuel wrote:
> use the same ly source for two different projects and yet produce 
> different output versions by simply invoking lilypond with the 
> appropriate --init option on the source. 

I think often all you need is a clever \include structure and invoking 
different .ly files, which apply different settings and both include the 
same content, like

% print-large.ly
\version "2.19.53"
#(set-global-staff-size 20)
\include "score.ily"

% print-small.ly
\version "2.19.53"
#(set-global-staff-size 11)
\include "score.ily"

% score.ily
\include "music.ily"
\score {
  \music
}
%%%%%%%%%%%%%%%%


Another option might be using the -e option to initialise a Scheme 
variable, which then triggers a switch inside your .ly file.

HTH, Simon