Just found this on tcl.tk
	Quote:
	
	
		| Fred Limouzin: 2005/04/11 
 The file size command currently (i.e. Tcl8.4.9) does not support
 directories. A pure-Tcl solution involves adding recursively the size of
 files in the current and in sub-directories.
 
 Here's a Tk/GUI script that I wrote this week-end, which fits my
 need. I wanted a gradient-color indication for the size of directories.
 You can position the orange/yellow scale (size at which the color
 indicator is orange/yellow; below that value the indicator is gradient
 going toward green (size=0)) and the red scale (size from which the
 indicator is red!). A scale selector also lets you decide how many
 levels of sub-directories to display. read more...
 | 
	
 Get source code for 
directory size.
There is also a link on that page to source code from the UNIX du (disk usage) TCL implementation.
So, as I understand it, it's actually really not possible to get the size 
all at once. You have to recursively read the size from all files??
Or maybe I don't fully understand yet what I have found above....
DJ