[rrd-users] Supressing RRDTool "OK" message in pipe mode

Alex van den Bogaerdt alex at vandenbogaerdt.nl
Fri Feb 27 18:12:42 CET 2009

----- Original Message ----- 
From: "Phix" <mark at phix.me>
To: <rrd-users at lists.oetiker.ch>
Sent: Friday, February 27, 2009 5:09 PM
Subject: [rrd-users] Supressing RRDTool "OK" message in pipe mode

> This isn't a problem as such, more a quirk I am interested in solving. I 
> am
> running rrdtool in pipe mode (which is "rrdtool -" at the command line) 
> and
> passing it a graph definition. It then spits back a binary stream which is
> the PNG file data, but right at the end of this stream, it adds it's usual
> "OK" message, something like "OK u:2.86 s:0.14 r:3.00".
> Obviously, this isn't part of the PNG stream - is there anyway of turning
> this off so it doesn't print this "garbage" at the end? The documentation
> says that when pipe mode is invoked, RRDTool should suppress all other
> output except the PNG stream, but this is not happening in my case (I'm
> running RRDtool 1.2.18).
> Any feedback would be much appreciated.

The "graph" command does suppress any other output, but "rrdtool -" does 

I have no answer to your question about turning this off, but I do have a 
question myself:

I assume you do something like:  echo graph - DEF:... AREA:... | rrdtool -

Why? Why are you doing this in pipe mode?

Maybe I'm missing something here, but I see no benefit in running a single 
rrdtool command in pipe mode.

Changing your command line to "rrdtool graph - DEF:... AREA:..." would solve 
the problem, but does not answer your question.


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