screen resolution?

[Alexander Larsson <alla lysator liu se>]

Is there any way in gtk/gdk to get at the real resolution (in dots per inch) 
of the screen?

xdpyinfo says:
screen #0:
 dimensions:    1152x864 pixels (390x293 millimeters)
 resolution:    75x75 dots per inch

I don't know how accurate this is, but at least there are some data about this 
in the x-server. Better use them than guessing at 72 dpi.

/ Alex