Tree command for Mac

With files:

find . -print | sed -e 's;[^/]*/;|____;g;s;____|; |;g'

With directories only:

ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/ /' -e 's/-/|/'