Add some Clojure-isms to your favorite shell. The idea isn't to give you Lisp in your shell but to give you the Lispy building blocks for operating on files and streams.
Just add this directory to your PATH and you're good to go!
# write the first line of the file to stdout
> first file-path
# drop the first line of ls and write the rest to stdout
> ls | rest
# write only the executable files to stdout
> ls | filter '[ -x $1 ]'