In Window, at the command line, you can type start index.html and it will open a web browser and load and display the page. This works for all registered filetypes. (e.g. PDFs, jpg …)
In Linux the same thing is possible, but the mechanism’s different.
If you’re using a gnome-based desktop (e.g. Ubuntu), add this:
# Open files and folders directly from the command line # e.g. gnome-open README.PDF # which with this alias becomes: g README.PDF # This also works with folders # e.g. g . will open the current folder alias g='gnome-open'
either directly to the end of ~/.bashrc or preferably, create a new file called .bash_aliases and put it in there.
Instead of gnome-open, a possibly better way is to use xdg-open. I think this works on many desktops but I’m vague on the details. It certainly works in KDE.