This is probably specific to Linux and I am adding it here as it's not a general Audacious message.
Rather than launch a command/script for every single song change, I've been trying to launch a single background script to listen to a named pipe. Audacious/Song Change would then write certain variables to the pipe which the background task would then read, format, and send off to a log file.
But... I've not come up with a way to get Song Change to accept something like, say, "echo '%a - %b - %T' > named-pipe" that actually sends anything to the pipe.
Is this currently possible?