There are now errors when updating and I cannot install most software due to a corrupted
file. Is there a copy I can download to replace it?
The file would be for Ubuntu 12.04 (Final Beta) in the United States.
You can use this trick. Open a terminal ( Pressing Ctrl+Alt+T ) and do these
Move the corrupted one to the safe place
sudo mv /etc/apt/sources.list ~/
and recreate it
sudo touch /etc/apt/sources.list
Open Software & Updates
This will open
software-properties-gtk with no repository selected.
Then, change the server to Main server or to any other server of your choice. You must enable some repositories from the new window in order to create a new
sources.list file in
After enabling some sources from Ubuntu software tab, you can enable updates. To do so, switch to Updates tab and select one or more updates channel. I recommend selecting the security and updates channels at least. (This image is later added from Ubuntu xenial, so there can be some differences)
Updated with inline content
This is the
sources.list file for 12.04 Precise Pangolin.
###### Ubuntu Main Repos deb http://archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse ###### Ubuntu Update Repos deb http://archive.ubuntu.com/ubuntu/ precise-security main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ precise-updates main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ precise-proposed main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ precise-security main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ precise-updates main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ precise-proposed main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse ###### Ubuntu Partner Repo deb http://archive.canonical.com/ubuntu precise partner deb-src http://archive.canonical.com/ubuntu precise partner ###### Ubuntu Extras Repo deb http://extras.ubuntu.com/ubuntu precise main deb-src http://extras.ubuntu.com/ubuntu precise main
If you're using another release, you need to replace the
precise word with your Ubuntu release name. You can see which name you should use with this command:
lsb_release -c -s
To replace the word, you can use this
sed command (assuming you copied the sources content in
sudo sed -i "s/precise/$(lsb_release -c -s)/" /etc/apt/sources.list
Note 1: the word
deb-src refers to the repository format.
deb is for binary packages and
deb-src is for source packages.
Note 2: Using
# at the start of the line makes that line a comment.
apt will ignore it, so any repositories mentioned on that line will be disabled.
Note 3: There are repository lines which includes all four components:
multiverse. You can disable one or more of them by removing the word.
Note 4: You can find some explanation of the repositories in this my other answer
Select your Country and Ubuntu Release.
For the default set of repositories, you need to enable these repositories.
If you want to install software from Canonical Partner Repositories (closed source software), enable the Ubuntu Partner Repositories (both of them).
Enable any 3rd party repository you wish to enable.
Now, click the Generate List button at the bottom of that page and you'll see your generated sources.list.
Run the following commands in a Terminal.
sudo mv /etc/apt/sources.list /etc/apt/sources.list.old gksudo gedit /etc/apt/sources.list
Copy/paste all the text from the newly generated sources.list to this file. Save it and close Gedit.
Now, update apt.
sudo apt-get update
This will update your repository index with the current sources.list and then you can install any software using Software Center, Synaptic or apt-get.
By default there will be a backup for your sources.list file on the same directory itself.
sudo cp /etc/apt/sources.list.save /etc/apt/sources.list
Answer from similar question here: https://askubuntu.com/a/465210/150936