It’s like using the internet, but instead of downloading stuff, you put it on a disc and then insert that disc into your computer. Pretty cool, right?
So how does this work exactly? Well, let me break it down for you in simpler terms:
1. First, you need to have some physical media (like a CD or DVD) with the software you want to install on it. This is called a “source”.
2. Next, you need to tell APT where this source is located. You can do this by adding a line to your `sources.list` file that looks like this:
# This line specifies the type of package (deb) and the architecture (amd64) for the software source.
# It also includes the URL (http://example.com/software) where the source is located, the release (stable), and the components (main, contrib, non-free) that are available from this source.
deb [arch=amd64] http://example.com/software stable main contrib non-free
This tells APT where the software is located (in this case, at `http://example.com/software`) and which version of Ubuntu it’s compatible with (in this case, “stable”). You can also specify other options like `arch`, `dist`, and `component`.
3. Once you’ve added the source to your `sources.list` file, you need to update APT’s package database by running:
# This script updates APT's package database by running the `apt-get update` command.
# The `sudo` command is used to run the following command with root privileges.
sudo apt-get update # This command updates the package database by retrieving information from the sources specified in the `sources.list` file.
# To add a new source to the `sources.list` file, you can use the `add-apt-repository` command.
# This command allows you to specify the source's URL (in this case, `http://example.com/software`) and other options like `arch`, `dist`, and `component`.
sudo add-apt-repository http://example.com/software # This command adds the specified source to the `sources.list` file.
# After adding a new source, it's important to update the package database to include the new source's information.
# This can be done by running the `apt-get update` command again.
sudo apt-get update # This command updates the package database to include the new source's information.
This will download a list of all the packages available from the sources you specified in your `sources.list` file and store them in a local cache on your computer. This can take a while, especially if you have slow internet or are using an old version of Ubuntu that doesn’t support HTTPS (which is why we added the `http://` prefix to our source URL).
4. Once APT has finished updating its package database, you can install software from your physical media by running:
# This script installs a package using the apt-get command with root privileges
# Update APT's package database to ensure the latest version of the package is installed
$ sudo apt-get update
# Install the specified package
$ sudo apt-get install <package>
This will search for the specified package in all of the sources listed in your `sources.list` file and download it (if necessary) before installing it on your computer. If you have multiple versions of a package available from different sources, APT will automatically choose the best one based on its own internal rules (which are beyond the scope of this tutorial).
5. And that’s pretty much all there is to managing CD and DVD sources in APT! It’s not as complicated as it might seem at first glance, but it can be a bit tricky if you don’t know what you’re doing (which is why we added the `http://` prefix to our source URL). But with a little practice, you should be able to handle most common scenarios without any problems.
Managing CD and DVD sources in APT: simpler than ever before.