[RndTbl] Monitor detection

John Lange john.lange at open-it.ca
Fri Aug 10 11:56:55 CDT 2007

To answer my own question from a while back:

The command is dccprobe.

So something like:

dccprobe |grep "analog signal"

Will tell you if you have a second monitor attached.

For debian/ubuntu (and I assume Fedora) fans, there is some good
information here:


I put the (modified) script from that page in:


And it works like a charm!

But SUSE does not include dccprobe so you will have to find dccprobe
source and compile it yourself. I actually just used the source from the
debian package (because I couldn't find it any place else):


Just untar, cd dccprobe, make. Then copy ddcprobe to someplace useful
like /usr/local/sbin/

Now when I boot my laptop it automatically goes into either Xinerama
mode, or clone dual-head mode depending on if I have another monitor
attached or not.

I also have two small scripts that I can use to force it one way or the
other if I plug in a monitor after booting.


On Wed, 2007-07-11 at 12:21 -0500, John Lange wrote:
> I know someone mentioned this at a distant past MUUG meeting; what is
> the command line tool that will query the attached monitor for its
> settings? I believe this is called DDC?
> I have a laptop and I'd like to have a command line tool that can detect
> if a second monitor is attached.
> Any tips?
> John
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> Roundtable at muug.mb.ca
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