sed and less can both look at multiple files (sed with --in-place, and less always). sed -r is extended regexp (as opposed to -E in grep - why? who knows), less

sed and less can both look at multiple files (sed with --in-place, and less always). sed -r is extended regexp (as opposed to -E in grep - why? who knows), less -r is to disable control character filtering, and less -R is to disable control character filtering for color codes only.