We've got space for 26^2 2-letter commands... > for d in $(echo $PATH | tr ":" "\n") ; do ls $d | grep "^..$"; done | sort -u | wc -l > 52 I can fit a f

We've got space for 26^2 2-letter commands... > for d in $(echo $PATH | tr ":" "\n") ; do ls $d | grep "^..$"; done | sort -u | wc -l > 52 I can fit a few more in (edit: I can't work out how to put code in a comment)