I'd like to query my monitor to change my xorg.conf file on-the-fly. I have a box that I connect to two different monitors. One is a 1680x1050 monitor (DVI-D), the other is 1920x1080 HDTV (HDMI). I'd like to extract/parse the monitor name to use the correct xorg.conf.

This is with 13.0 32-bit. I'm using NVIdia 185.18.31 proprietary drivers. As this is the new X system, my xorg.conf is minimal only to support the proprietary drivers.

I looked at xorgsetup, which basically is a wrapper for 'X -configure'. I don't want to create a new xorg.conf, just extract/parse the EDID info from the monitor in a human readable manner.

Perhaps the easiest solution is to let 'X -configure' create a new xorg.conf, extract the monitor name, delete the new xorg.conf, and install the correct pre-made xorg.conf.

I admit that with the new X I might not need this information, but what the heck.

Another reason for knowing this is so I can reconfigure Xine on-the-fly to use the correct audio port (HDMI or external speakers).

Thanks again.

A few things I found by googling:

http://john.fremlin.de/programs/linux/read-edid/ <-- Looks good.
http://wiki.mandriva.com/en/Tools/monitor-edid <-- I arrived to the previous link through here.

Thanks, I saw that link too, but I read somewhere that read-edid won't work with AMD 64 setups.

Doesn't that information (VendorName and ModelName) appear in the Monitor section of xorg.conf? If so, are you asking for a script which will extract (using eg SED, AWK, etc) and print the information?

Indeed, the second link mentions that it has to go through some kind of emulation.

No, I want to extract the information from the monitor so I can use the correct xorg.conf before starting X. I have two prebuilt xorg.conf files, one for each monitor. I swap the files before starting X when I move the machine. I started doing this long ago when I wanted to swap video drivers, say toggling between nv and nvidia. Was much faster and handier than always manually editing xorg.conf.

You might try using a program called 'ddcxinfo' but I was unable to 'make' it on Slackware 13.

The following commands will use Xorg to probe the monitor and output a line of EDID data which should uniquely identify each of your monitors (and not change over time). The outputted line contains the manufacturer, model, and serial number -- though it is encoded in hexadecimal format.

The approach is rather ugly and may not suit your purposes, but I thought I'd post it just in case.

Actually, the probeonly option might suffice. Although I get different results depending upon which version of X I'm using. Regardless, the info I need from the resulting Xorg.x.log is available.

I notice there is one consistent snippet regardless of which monitor or computer I run the probe, or which version of X:

(--) NVIDIA(0): Connected display device(s) on GeForce 6150 at PCI:0:5:0:
(--) NVIDIA(0): Samsung SyncMaster (CRT-0)

or:

(--) NVIDIA(0): Connected display device(s) on GeForce 8300 at PCI:2:0:0:
(--) NVIDIA(0): Acer X193W+ (DFP-0)

The Samsung is an LCD monitor but uses the VGA adapter, hence the CRT designation. I haven't yet tested this probing with the HDTV.

From there I can use grep to return a line number for the "Connected display device..." line. For example, line 447. Then I can run 'head -448 /var/log/Xorg.1.log | tail -1' to extract line 448.

Thanks much!

The EDID info is available at /proc/acpi/video/<some unchanging video adapter>/<some unchanging video port name>/EDID

I've used the "state" file in that same location to probe whether a monitor is connected or not in order to do a similar thing.

The EDID data is binary, but I'd imagine you could find an API or something to decode it and that Monitor name is in there somewhere.