I find it difficult to believe an efficiency article that tells me that 'e' is shorter than 'emacs' but to write a 15-line perl script to replace 'uniq -c'. Add to that the cdto script, which replaces pushd crudely and without recursion.

Premature optimization. Spend more time learning about the tools you already have, then figure out how to shave whole seconds (over the course of a year) off using them.