Git Blame

$ git blame -L start_line,end_line file —
$ git blame -L start_line,+5 file — you can specify prev / more lines
$ git blame -L "/regex/",+5 file — you can use regex, you can optionally pass in a commit hash id before the file name

Git Revert

$ git revert — rolls back the previous commit, committing immediately
$ git revert -n HEAD — roll back without committing
$ git blame -L "/regex/",+5 file — you can use regex, you can optionally pass in a commit hash id before the file name