Hi,

there are two options to enable syntax highlightning in vi/vim.

Just for your current editor session. Open your file

michael@debdev # vi ./src/examples/knxtool.c

and enable highlightning

ESC
:syntax on


Or persitent. Open .vimrc in your home folder

michael@debdev # vi ~/.vimrc

and add

syntax on


To show line numbers add

set number


Michael