M-/
Completes the token (in emacs) or the directory in bash.
less whatever.tar.gz
This actually lists the files in the compressed archive!

And here’s some useful keystrokes for emacs

Run this:
mysqld_safe --skip-grant-tables --user=root &
Then:

UPDATE mysql.user SET Password=PASSWORD('newpwd') WHERE User='root';
FLUSH PRIVILEGES;

Unfortunately, the info on the mysql site seems to be a bit wrong!

List connections in a useful manner:
netstat -a -tcp

echo ${!file_list} will echo $$file_list, so say $something = john and $cat = ‘something’, echo ${!cat} would be something, gettit?

Specify the display before the application:
DISPLAY=:0 btdownloadgui.py