If you have a new distribution of Linux, do these modifications to these files in your home directory. They take effect after next login.
~/.bashrc: alias ls="ls ‐‐color" ~/.cshrc: alias ls 'ls ‐‐color'
That’s it!
You may also want to do an « eval `dircolors $HOME/.colourrc`
», to get your own colours. This file is created with « dircolors -p >$HOME/.colourrc
» and is well commented for further editing.