I want QuickTime Player to auto-play a file when I execute that file from Finder.
The default behaviour is to simply load the file and wait for you to press play.
I found a default pref that you can set to force QuickTime X to play movie files automatically.
defaults write com.apple.QuickTimePlayerX MGPlayMovieOnOpen 1
How can you force QuickTime to play all its files automatically, regardless of their type (mp3, wav, aac, etc)