Associate scripts with Shairport

As wirtten elsewhere, I use a script to turn on and off my external speakers when music from MPD plays and stops.
I would like the same with Shairport.
I found that Shairport offers the options -B and -A that allow the user to execute scripts on play and stop.

I don’t know if it is worth to offer such option to everyone, but in general I thought it was worth to mention it.

For the time being I modified the /etc/init.d/shairport script.