[ggm]

If I wound up on a host in /rescue mode awk would be my go-to to fix up 'convert this to that' changes, maybe even grobble into the piped inputs of other commands to get debug data marshalled up. If you have a bigger system, there are better tools. If you have to live in the small state of a /rescue, knowing how to use sed/ed/grep/awk is data-saving.

Sometimes people observe I'm using three tools with pipes to do one job, and I freely admit grep <pat> file | awk '{print $2}' | sed -e 's/this/that/g' is probably stupid, but I do think of these atoms as tools for the job. Grep aside, sed and awk should be fully interchangeable for many pipe jobs, and when not BEGIN{} ... END{} you could do the whole thing in awk or sed simply. If it has pre- and post- states, Awk is ideal. But.. the mind does what the fingers remember.

Pipes are cheap.