Async shell-command-to-string?

[Johan Lindström]

Hi all!

I'd like to run something similar to shell-command-to-string, but 
that runs "asynchronously" in a "subprocess" in the "background". 
I've searched for all those things without finding anything suitable.

async-shell-command-to-string or whatever it would be called would 
take a callback for the string output when the subprocess is done.

Is there anything like that already?

If not, any hints on how to implement it? The async part of 
shell-command looks promising to nick.


/J