How to exclude everything from TimeMachine backup except one folder TimeMachine backs up all my mac and also if I have external hard drives will  back them up too.
My goal is to add some general exclusion list that basically stops it from backup my mac and ONLY want it to backup my external hard drive. 
I thought if I add the hard drive labeled "Macintosh" to exclusion list then it won't backup my mac, but it did!
So basically I have two external hard drives ( A 2TB Lacie and a 2TB Apple AirPort Time Capsule) and I want time machine to only backup my Lacie one to the AirPortTime capsule one but don't want to to backup the rest of my laptop because I won't have enough space for that.
You can use bash script deux_ex_tmachina to help you generate desired blacklist.