Alt + . does the same thing as well, with the added advantage that you can keep pressing alt and then hit . several times to go through all the "last arguments" in your history one by one.
Further, holding Alt followed by numeric argument followed by dot, gives you an argument at a specific position. For example, Alt + 1, Alt + . copies the first argument.
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.
I know that this expansion exists, but never use it in practice.
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.
Yes I was also impressed when I found out about this one. However I use it far less frequently than ALT-. . ALT-# is also useful in the frequent cases where I am constructing a complicated commmand but I have to run another command before the current one.
Also keep in mind that most interactive command-line tools are built upon readline and can understand all those bindings (think python REPL, mysql/psql...)
I use that on test machines a lot and had put it in bashrc and heard some cussing from other devs so now I just have to type it every time I spend more than acouple seconds in a terminal :) .
Further, holding Alt followed by numeric argument followed by dot, gives you an argument at a specific position. For example, Alt + 1, Alt + . copies the first argument.