[suprgeek]

A lot of the suggestions in this post are "idempotent" only in the sense of the specific use case that the author is interested in. Please do not take this advise to be generally applicable for the uses of "idempotent" or in general to mean best practice while writing bash scripts.

The advice such as replace rm <FileName> with rm -f <FileName> could lead to Disaster depending on the scenario. So a HUGE YMMV