How can I enable non-free packages on Debian? I want to install Sun's Java JDK but it's not available to me.
/etc/apt/sources.list, and you should see lines like the following (URLs will likely vary):
deb http://http.us.debian.org/debian stable main contrib
non-free to the respective URLs you wish to use, i.e.:
deb http://http.us.debian.org/debian stable main contrib non-free
apt-get update will update your local repo with the package listing.
You can also restrict this a little bit if you only want some very specific packages from non-free (firmwares for your hardware for example).
To do so, keep your
/etc/apt/sources.list as described by @Andrew M. Then, use Apt Pinning to disable by default all non-free packages for your current release:
Create a file named
/etc/apt/preferences.d/non-free_policy containing the following directives:
Explanation: Disable packages from non-free tree by default Package: * Pin: release o=Debian,a=stable,l=Debian,c=non-free Pin-Priority: -1
Now, create another file for the specific package you want to get from non-free.
Let's assume you want to add the Intel drivers for wireless cards for instance (package firmware-iwlwifi).
Create a file name
/etc/apt/preferences.d/firmware-iwlwifi_nonfree with these lines:
Explanation: Enable package firmware-iwlwifi from non-free tree Package: firmware-iwlwifi Pin: release o=Debian,a=stable,l=Debian,c=non-free Pin-Priority: 600
This configuration avoids bloating your package with these annoying non-free packages ;)
An alternative way to update the package sources configuration file is to use the
apt-add-repository command (from the
software-properties-common package). If you want non-free package for all sources, run:
sudo apt-add-repository non-free sudo apt-get update
Answer inspired by: https://askubuntu.com/a/553847/67211