[rrd-developers] Patch to get more metadata out of 'rrdtool graph'

Tobias Oetiker tobi at oetiker.ch
Sat Aug 25 00:23:25 CEST 2007

Hi Mark,

I will be glad to accept such a patch ... BUT ... it has to be done

rrd_graph may not print anyting directly. it must return its
information to the caller who is then responsible for dealing with
it ... look how this is done currently for the size of the graph
and the return data for PRINT: ... unfortunately this code does not
realy lend it self to extension, so I guess what would have to be
done, is to add an option to rrdtool which enables a different kind
of return values ... (this is necessary to  NOT break existing

have a look at rrd_info.c to see what kind of interface for
returning arbitrary data I would like to see ...

in that way  rrdtool could retorn a ton of data about the graph and
all its properties to the caller ...


Yesterday Mark Plaksin wrote:

> Here's a small patch against the 1.3 trunk which makes life easier for
> my buddy's Google Maps-like web interface to RRDs.  It's Google
> Maps-like in that you can drag the graph part of the image left and
> right in time.  Demo site & code coming soon.
> The patch adds three options to the 'rrdtool graph' command-line:
> a) '-1' makes rrdtool display the scale (im->minval,im->maxval) of the
> graph.  This is used by the next option.  Sample output:
> 	scale: 0.00,99.00
> b) '-2 MIN,MAX' forces the scale to MIN and MAX.  To force the scale to
> be what was returned in the example above you would use:
> 	rrdtool graph -2 0.00,99.00
> c) '-3' Display the coordinates of the upper-left corner of the graph
> part of the image and the length and height of the graph (in pixels).
> Sample output:
> 	graph_coords: 57,30,400,100
> Obviously argument names are random :)
> Would you add this or something like it?  It might be helpful to be able
> to get arbitrary properties of the graph and/or image out via the
> command-line but these three options are doing the trick for us at the
> moment.
> Thanks & thanks for RRDtool!
> PS:  I have a patch against 1.2 also; let me know if you like that too/instead.

Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten
http://it.oetiker.ch tobi at oetiker.ch ++41 62 213 9902

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