bat

Generally a cat replacement for viewing files, but fancier.

To open a file in a pager (like less):

bat flake.nix

To open a file without a page (like cat):

bat flake.nix --pager=never

To use bat as a previewer for fzf:

fzf [...] --preview "bat --color=always --style=numbers --line-range=:500 {}"