Useful scripts, configs, and other goodies for Linux environment

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Enable global tty read/write privileges for all users

Run the following command in the terminal:

$ sudoedit /etc/udev/rules.d/50-myusb.rules

Add the following lines to the file:

KERNEL=="ttyUSB[0-9]*",MODE="0666"
KERNEL=="ttyACM[0-9]*",MODE="0666"
KERNEL=="tty[0-99]*",MODE="0666"
KERNEL=="ttyS[0-99]*",MODE="0666"

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Add newer versions of packages

In case a program requires pre-compiled system binaries, libraries, or packages which are not directly supported by your distro, but exist in newer distros, there is a way to add those.

Add Ubuntu Jammy (22.04) source index to the machine's source list file:

echo deb http://cz.archive.ubuntu.com/ubuntu jammy main >> /etc/apt/sources.list

Update source index:

sudo apt update

Install required packages, e.g.:

sudo apt install libc6

After installing the packages/libraries, it is IMPORTANT to delete the previosly added to the source index file:

sed '$d' /etc/apt/sources.list

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Install multiple python versions on a Linux machine

Installing multiple versions of Python on a Linux machine can be done through a variety of ways. Here, I'll describe how you can do this using the pyenv utility, which allows you to easily switch between different Python versions.

1. Install pyenv:

First, you'll need to install some dependencies for pyenv and Python build:

sudo apt-get update
sudo apt-get install -y build-essential libssl-dev zlib1g-dev libbz2-dev \
libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \
xz-utils tk-dev libffi-dev liblzma-dev python-openssl git

Then, you can install pyenv using the pyenv-installer script:

curl -L https://github.com/pyenv/pyenv-installer/raw/master/bin/pyenv-installer | bash

2. Add pyenv to bash so command line knows about it:

Add pyenv to your ~/.bashrc:

echo 'export PATH="$HOME/.pyenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init --path)"' >> ~/.bashrc
echo 'eval "$(pyenv virtualenv-init -)"' >> ~/.bashrc

Restart your shell:

exec $SHELL

3. Install Python versions:

Now, you can install the versions of Python you need. For instance, to install Python 3.6.9, you would run:

pyenv install 3.6.9

Do the same for other versions you want to install. Use pyenv install --list to see available versions.

4. Set Python versions:

You can set the global Python version default with pyenv global. For example:

pyenv global 3.6.9

This makes Python 3.6.9 the default python when you open a new terminal.

You can also set local Python versions (for individual projects/directories) with pyenv local. If you're in a project directory and run:

pyenv local 3.8.5

Python 3.8.5 would be the default Python for that directory.

To switch between Python versions on the fly, you can use the pyenv shell command:

pyenv shell 3.8.5

Add the following to .bashrc:

export PYENV_ROOT="$HOME/.pyenv"
command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"
eval "$(pyenv init -)"

This makes Python 3.8.5 the default Python for the current terminal session.

Remember to replace 3.6.9 and 3.8.5 with the actual versions of Python that you want to use. If you're not sure which versions of Python are installed, you can list them with pyenv versions.

Add custom keyboard mapping and functionality using XKB

IMPORTANT: Before doing anything with XKB, make sure to backup your current setup in /usr/share/X11/xkb/. In addition, have a way to be able to input commands in case you are locked out from using the keyboard because of a bad config - best way is to have a CD or USB boot drive from which you can load into an isolated linux environment and mount your drive; at which point you can fix the bad config.

To add setup the arrowless keyboard layout from this repo all you need to do is delete /usr/share/X11/xkb directory and move the xkb_arrowless_setup folder to the same place (should be named xkb).

To initialize the new setup you can either logout/restart, or use command sudo udevadm trigger --subsystem-match=input --action=change.