Cool one. "Ctrl + R" also does the same thing to search through past commands and then "Tab" to select the command you are looking for.
!-1:gs/hello/world
which runs the last command with all instances of hello replaced by world. !-1 can be any so called event designator, for instance !n to refer to any specific line number from history or !string for last command containing a particular string.
Seriously people, read the man page for bash. Your shell has so many cool features.
$ echo "hello hello hello world" hello hello hello world $ ^hello^bonjour^ echo "bonjour hello hello world" bonjour hello hello world
Why? The last command is more general, you can just drop the g from the command I wrote to only replace the first occurrence. Besides, :[g]s/old/new should already be familiar to anyone who has used vim, so that is almost like having to learn zero new things.
^-t