Normally syntax highlighting is the default behavior.
You can enable it manually by hitting :syntax on
But normally you'll have this error because of the missing package.
E319: Sorry, the command is not available in this version
Solution install the vim-gui-common package:
apt install vim-gui-common
After that you should find that the code is highli........
Within vi if you can't exit /etc/vim/vimrc you can type
:syntax off
And to turn it back on:
:syntax on
Many of us have a dark/black background in our terminal/shell making the default syntax unreadable, the solution is to either turn off syntax highlighting with :syntax off or to enable a special option in /etc/vim/vimrc
Edit /etc/vim/vimrc
The "syntax on" enables the highligh........