Bash: Let me bash that for you, Part 0

I was going to write about some Unix-like shell hints which I usually use like grep, sed, for loop, variables and so on. I noticed that I do usually use lots of bash kung-fu beyond the shadow of a doubt.

I'm not going to start a holly war what shell is the best one - sh, ksh or whatever. I know how to cook bash tasty - it has lots in common with sh but some nuances happen.

That isn't a bash tutorial or so - it's more like commonly used hints and tips.