CosmOS
> one.txt                 13
two.txt                 14
2 files
> renamed
> first.txt               13
two.txt                 14
2 files
> gone
> two.txt                 14
1 file
> no such file
> rename what to what?
> there is no such file, or that name is taken
> halted
Execution halted.
[exit 0]