This one-liner is great, it lists the commands you have used by popularity. At present, the 'cd' command wins in my history file with 140. Followed by ls (93) and ssh (56). What are your top 3 commands

Snippet source: ibm

This python class converts a permission mask in symbolic format (the kind a diretcory listing produces, ex.: drwxr-xr-x) to a string that's usable in a chmod command.

ex.: chmod u=rwx,g=rwx,o=rwtx ~/myscripts/convert_mask.py

This can be very useful when recovering permissions from a backup.