How little you know, and some useful commands.

If you ever find yourself counting up-arrows to repeat a sequence of commands (that aren't worth scripting for whatever reason), next time, go to the top of the list and hit Ctrl-O. The result is the the command runs, and the one after it in the history is loaded into you prompt.

dig +short google.com

    % set i = 1
    % echo $i
    1
    % @ i++
    % echo $i
    2
    % @ i *= 2
    % echo $i
    4

    $ ls -l 500.*
    $ ^500^600

    $ ls -l 500.*
    Up-arrow, control-left, delete, 6