Display image from Graphviz without creating an intermediate file? - command-line

Question

I would like to display a graph without writing a file first.
Suppose I have a command foo that produces this on standard out:
digraph foogrph {
a -> b;
a -> c;
}
What I would like to do is pipe foo into dot and then pipe the results into a command that will display the image in a graphical environment.
foo | dot -Tpng | <display command>
I have found a workaround that involves temporary files. In OSX, I can do the following:
foo | dot -Tpng > temp && open temp
But I still have to remove the file from the filesystem.
How can I display an image that is being written to standard out?

Answer 1

With ImageMagick's display command, these work on Ubuntu 12.10 (and most likely other OSes, too):
dot abac.dot -Tsvg | display
dot abac.dot -Tpng | display
SVG has the advantage of smoothly scaling with the window (if that's what you want).

Answer 2

On OSX & iTerm2, you can do the following (assuming imgcat is installed)
dot abac.dot -Tpng | imgcat

Answer 3

On Linux you can also just use -Tx11:cairo to display a direct X11 window.

Answer 4

To complete the accepted answer (which is totally OK), if one want to also avoid using a .dot file :
echo 'digraph { a -> b }' | dot -Tpng | display
(this is for linux only, also I first tried eog that doesn't seem accepting pngs through pipes)
Adapted from rom the documentation of graphviz command line usage.