update alternatives x terminal emulator code example

Example 1: set default terminal ubuntu

sudo update-alternatives --install /usr/bin/x-terminal-emulator x-terminal-emulator /opt/Hyper/hyper 50

Example 2: make kitty terminal the default terminal on ubuntu

sudo update-alternatives --install /usr/bin/x-terminal-emulator x-terminal-emulator `which kitty` 50
sudo update-alternatives --config x-terminal-emulator