Better Bash Scripting in 15 Minutes. The tips and tricks below originally appeared as one of Google’s “Testing on the Toilet” TOTT episodes. This is a revised and augmented version.
Some good bits in here. We’ve implemented some of them in devstack, and I think a few more (like uninitialized and enforcing double brackets on all conditionals) would be helpful. It also makes me think about things to enforce in bash8.
It's always more complicated 
+100 on the double brackets, the simple bracket form is so much error prone and fragile
LikeLike