The command line includes a powerful history feature that can make life much easier. To see the recently typed commands, type history. This simply dumps to the screen a hidden file in your /home directory called .bash_history where up to 1,000 commands are recorded. Because this list will scroll off the screen when listed, it’s a good idea to pipe the output into a text reader, such as less:

 $ history|less 

                                To reuse one of your commands, at the command prompt type an exclamation mark ( !; known as a bang in bash-speak) and then the number alongside the entry in the history list. For example, on my system, I noted when viewing the history list that the command cp /etc/fstab ~ /Desktop was command 591. To use it again, I typed !591 at the command prompt. If you ever need to simply repeat a command you’ve just used, type two exclamation marks— !!. 

To actively rifle through your command history, hit Ctrl + r and then start typing the command in which you’re interested. The prompt will “autocomplete” as you type. To use the command, hit Enter . To edit it before using it, hit Esc , and then make your changes. 

                     Hitting the up and down cursor keys will also let you move through the most recently typed commands. Just hit Enter when you find the one you want to reuse.

The easiest way of setting your own picture as a desktop wallpaper is to click and drag the image to the desktop using the middle mouse button (if the image is already on the desktop, then click and drag it a few inches to the left/right). On most modern mice, the middle mouse button is the scroll wheel, which also doubles as a third mouse button. On the menu that appears when you release the button, click Set as Background. 

                                        If that sounds a little too unorthodox for you (it can be hard to use the middle mouse button), you can also use Synaptic to install the nautilus wallpaper package, which adds a simple Set as Wallpaper option to the menu that appears when you right-click an image file. After installation, you’ll need to log out and then in again before the option becomes visible.