You can also `open -R $filename` and it will open the directory in finder with the relevant file selected.
`open .` will work on most Linux systems too.
Don’t think I’ve come a binary named open on a Linux machine. (And under Arch Linux, `pacman -F /usr/bin/open` produces nothing, so no package in the standard repositories contains it.) I’m guessing you’re thinking of `xdg-open .`.
There's also "see ."
Never heard of it, nor can I find any references to it, or Arch Linux packages containing it.
See this. I suspect it's installed by default on Ubuntu.