bat

bat is cat with syntax highlighting, line numbers and Git change markers built in. Type bat file.py and you get a color-coded, numbered view of the file, and long output goes to a pager automatically. Written in Rust by David Peter, who also wrote fd, and dual licensed MIT or Apache 2.0.

Pipe it into another command and it quietly behaves like plain cat, so scripts don't break. The README's recommended alias is alias cat='bat --paging=never'. Every major package manager carries it; on older Debian and Ubuntu releases the binary is called batcat.

Anyone who reads code in a terminal: install it. It costs nothing and changes nothing about how you work. The bat-extras companion scripts bring the same highlighting to grep, diff and man pages.

The catch is copy and paste. The line numbers and margin markers come along when you select text in the terminal. Use bat -p (or --plain) when you need clean output.