Pipe graphviz into OmniGraffle?

I’m a programmer visualizing my Docker images using a graphviz ‘dot’ file generator called DockViz. Its output is ugly and unbalanced. I’d like to pipe the output into OmniGraffle but I don’t know how to tell it that the standard input is a graphviz file.

This attempt:

dockviz images --dot | open -f -a OmniGraffle

yields the dialog 'The document “open_xxxx.txt” could not be opened. OmniGraffle cannot open files in the “text” format.

I’d rather not create a tempfile with extension .dot or .gv. I tried adding the “-h” bundle identifier argument to open but I get “Unable to find header file matching xyz”

Suggestions please??

Andrew Wolfe