TIL: Stripping ANSI Escape Codes From Terminal Output

Coloured terminal output is great for human eyes and terrible for log files. ANSI escape codes turn clean text into a mess of [32m and [0m sequences.

command_with_colours | sed -e 's/\x1b\[[0-9;]*m//g' > clean.log

The sed pattern matches the ESC character followed by bracket, optional semicolons, and the letter m. That covers most colour, bold, and underline codes.

command_with_colours | sed -e 's/\x1b\[[0-9;]*[a-zA-Z]//g' > clean.log

The broader pattern catches cursor movement codes too. When piping CI output to files or Slack messages, strip the codes first and save everyone the noise.

Is there a dedicated tool?

Yes. strip-ansi is an npm package. For one off use, the sed one liner is faster than installing anything.