Random tip: in Bash (at least), you can execute the previous command with some changes using ^..^..^, e.g. $ echo john regehr | sed s/hr/xx/ john regexx

Random tip: in Bash (at least), you can execute the previous command with some changes using ^..^..^, e.g. $ echo john regehr | sed s/hr/xx/ john regexx $ ^r/x^r$/^ echo john regehr | sed s/hr$/x/ john regex (The second last line is just bash printing the new command.)