How To Ubuntu » Command Line

How to enable the Universe & Multiverse repositories from the command line

Eli — Sun, 17 Jan 2010 21:38:40 +0000

Enabling the Universe & Multiverse repositories will give you access to tons of software that your Ubuntu system doesn’t give you access to by default. Here is how to enable them.

Open a Terminal. Applications > Accessories > Terminal
Type in:
sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak

This makes a copy of the file we’re going to modify, in case we need to restore it later.
Then:
sudo nano /etc/apt/sources.list

You can use nano, or your text editor of choice. For example, if you preferred gedit, you’d enter:

gksudo gedit /etc/apt/sources.list
Now, find the lines that look like these below, and remove the ” # ” that appears in front of them.
- deb http://us.archive.ubuntu.com/ubuntu/ hardy universe
- deb-src http://us.archive.ubuntu.com/ubuntu/ hardy universe
- deb http://us.archive.ubuntu.com/ubuntu/ hardy-updates universe
- deb-src http://us.archive.ubuntu.com/ubuntu/ hardy-updates universe
- deb http://us.archive.ubuntu.com/ubuntu/ hardy multiverse
- deb-src http://us.archive.ubuntu.com/ubuntu/ hardy multiverse
- deb http://us.archive.ubuntu.com/ubuntu/ hardy-updates multiverse
- deb-src http://us.archive.ubuntu.com/ubuntu/ hardy-updates multiverse
Save the file and exit.
Update with the new repository(s):
sudo apt-get update

Now you can install software from the Universe & Multiverse repositories. This software should appear in Add/Remove when you tell it to show you All available applications. Click the picture to enlarge.

Shortcut to root command line access while logged in as un-privileged user

Eli — Tue, 01 Sep 2009 03:27:03 +0000

Let’s say you’re logged into your Ubuntu machine as an unprivileged user, meaning that you don’t have permission to use the sudo command on the command line. As such, you cannot update the system, install a program, or perform other tasks in the terminal that require the sudo command without logging out and then back in as the administrative user, or using the User Switcher. This annoys me. So, how do I execute commands in the terminal that require the sudo command while still logged in as the unprivileged user??

First off, you’ll need ssh. To make sure you have this installed, login to your administrative account (a step that will soon become unnecessary), open a terminal, and enter…

sudo apt-get install openssh-server openssh-client

After this install is finished you can logout, and back in as the unprivileged user.Now you can open a terminal and enter…

ssh [administrative username]@127.0.0.1

You’ll be asked for your password, this is the administrative account’s password, enter it and press enter. Now, you’ll have a command line prompt for the administrative user, as if you had logged in as that user and opened a terminal. You can now update the system, or make whatever change you need to make that requires you to enter your sudo password.

A nice time saving trick.

How to find out which version / release of Ubuntu you have

Eli — Thu, 27 Aug 2009 05:16:21 +0000

Have you ever asked yourself, “How do I find out exactly which version, or release, of Ubunut I have?” There are a few ways of doing this.

The easiest, and most basic, is to open the System Monitor.You do this by going to System > Administration > System Monitor. You then click on the System tab. There you’ll see which version of Ubuntu you’re using, along with your linux kernel, and which version of gnome you have. However, this information can be incomplete. For example, if I do this, I’m told that I have Ubuntu 8.04. Well, I do, but there’s more to it than that.

See, Ubuntu has what’s called point releases for the long term support versions of Ubuntu, which 8.04 is. Check their website here, for an explanation. So, knowing that I have Ubuntu 8.04 does not tell me which point release I have. What can I do if I want that information?? Well, that’s pretty easy too.

I have to open up a terminal. To do that I go into the Accessories menu, and choose Terminal. Then I enter this…

cat /etc/issue.net

And when I do that, I’m told that I have Ubuntu 8.04.3 LTS. This let’s me know that I am using the third point release. This is what I wanted to find out.

Any other ways of doing this that you prefer???

How to lock your screen from the command line

Eli — Thu, 11 Dec 2008 23:35:29 +0000

This could be very useful to you if you’re working in the terminal and need to step away for a moment. You can achieve a locked screen, just like when you do it the graphical way, with this command entered at the command line, or cli…

gnome-screensaver-command --lock

This will instantly launch your screensaver, and lock your computer’s screen. Your password will be required to gain access to your system once this is activated.

That command is pretty long, and typing it out would probably get on my nerves. You can use an alias to effectively shorten it. Here’s how we’ll do that, also at the command line…

Let’s say we want to be able to type in lock, to lock the screen. If I just type in lock, I get nothing. So I need to create an alias for this command. An alias is just like what it sounds like. It’s assigning another name to a certain command. At the command line enter…

gedit .bashrc

There’s a certain section of this file that talks about aliases. You can add this line of text to that section of the file…

alias lock='gnome-screensaver-command --lock'

This tells Ubuntu that when you type in lock, it executes gnome-screensaver-command –lock. Click the Save button and close the text editor. The next time you login, the change will have taken effect. Try it out and see how you like it.

Here’s what it should look like…