I don't have an internet connection on my PC. So, can I download software on my Android and then install them on Ubuntu 16.04? Please provide a step by step guide.
You can successfully install software without an Internet connection if the software is fully packed with all met dependencies of which is something very hard to achieve!
Otherwise, you have to manually install all dependencies which is something very painful as most packages need many dependencies of which these dependencies packages need other dependencies in order to work (the chain goes on).
Updating Ubuntu offline
Whenever a new version of Ubuntu is released (if you're sticking with LTS, this means every new point release of the LTS (e.g. 14.04.5 LTS), which is where all the updates are included in the install USB/DVD), backup your files, download the new release, make an install USB/DVD with the .iso, boot from the install USB/DVD and, during the install process, there should be an option to upgrade from your previous version of Ubuntu to the one on the install USB/DVD (e.g. upgrading from Ubuntu 16.04 LTS to Ubuntu 16.04.1 LTS), select this option, install as usual. If something goes wrong, run the install USB/DVD for the new version of Ubuntu again but this time select the option to wipe everything and manually restore all the files and software you'd installed previously.
Installing/running specific software (Everything other than Deb)
Given installing Debs offline is a bit of a nightmare since Debs don't bundle dependencies, this is the recommended route if it's possible.
- Search for the software you want online
- Download the Linux version of the software (for the correct architecture, 32-bit or 64-bit)
- Plug your Android device into your computer (probably with a microUSB-to-USB (male-to-male) cable), find the folder where the file was downloaded into on the device (probably Downloads), select it, right-click it and click 'Copy' or 'Cut', find a folder on your computer to save it in, right-click in an empty space and click 'Paste'.
- Follow the install instructions for that software to install/run it.
Installing or updating specific software (Deb)
If you're going to install a Deb package, it's best to get it the official package from the Ubuntu repository.
- Download the relevant Deb package onto the Android device
- Go to Ubuntu Packages Search
- Select your Ubuntu version in the dropdown in the Search section
- Search for the package you want in the Keyword box and click Search (you might want to Google '[program name] Ubuntu package' to find out what the Ubuntu package name for the program is)
- Click the link on the distribution version
- Click on the architecture link for your architecture
- Click on the nearest mirror, that should download the file
- Repeat steps 1.5 and 1.6 for all the dependencies you don't have installed (that could be quite a lot!) (To check what dependencies you do or don't have use
dpkg-query -l packagenamein Terminal. If you get anything other than
dpkg-query: no packages found matching xonoticthen you have the package installed already. Note, you may also need to install the dependencies of the dependencies, and the dependencies of the dependencies of the dependencies etc.)
- Plug your Android device into your computer (probably with a microUSB-to-USB (male-to-male) cable), find the folder where the files were downloaded into on the device (probably Downloads), select them all, right-click them and click 'Copy' or 'Cut', find a folder on your computer to save them in, right-click in an empty space and click 'Paste'.
- Install each package one by one, starting with the lowest dependencies working upwards. Just double-click on each one to install it with Ubuntu Software.