!! history substitution gives a copy of the
Most people use it to re-execute the previous command line.
Sometimes I want to repeat a cycle of two commands, one after the other.
To do that, I just type
!-2 (second-previous command) over and over:
vi plot... %
vtroff -w plot... %
!-2vi plot ... %
!-2vtroff -w plot ...
You can cycle through three commands with
!-3, four commands
!-4, and so on.
The best part is that if you can count, you never have to remember what to do next.