[Inkscape-user] Resize an image from the command line

I want to scale an SVG file/object while preserving h/w ratios.

In the gui, this would be done by clicking on the object, choosing object-->transform-->scale-->preserve ratio-->(enter scale) then file-->properties-->resize canvas to fit object. As you can see, that's a lot of work for an operation that should be really simple.

Anyway, I tried figuring out how to use the shell mode, and didn't manage it. I assume I need to use the verb "DialogTransform" but that's as far as I got. Any help would be appreciated.