rrdtool batch dump command for windows

[cwalton]

I'm sure it's been posted somewhere before, but I couldn't successfully search for it. So, I'm going to post what worked for me in the hopes that it may assist another user somewhere down the line. I copied my rrdtool.exe into the cacti\rra\ directory to make it simpler.

At the command prompt, in directory cacti\rra:

for %x in (*.rrd) do rrdtool dump %x >%~nx.xml