#MacOSX : Display EDID [UPDATED]

EDID (Extended Display Identification Data) enables Mac OS X to know what kind of monitor is connected to it.
Why are we interested in it? If we know the exact model of LCD connected to our mac we can retrieve who is the manufacter of the panel (which often it is not the brand under the monitor is sold) and its properties (like response time, contrast and brightness) as Apple doesn’t specify they in its own products.

So here we go:

  1. Open Terminal app.
  2. Type (see this comment):
    ioreg -lw0 | grep IODisplayEDID | sed "/[^<]*</s///" | xxd -p -r | strings -6
    ioreg -lw0 -r -c "IODisplayConnect" -n "display0" -d 2 | grep IODisplayEDID | sed "/[^<]*</s///" | xxd -p -r | strings -6
  3. Second line is what we are looking for.

NOTE: if you are interested in how this work, you can type in Terminal (but be ready for a full NERD immersion):

  • man bash
  • man ioreg
  • man grep
  • man sed
  • man xxd
  • man strings

Don’t say i haven’t Warned you! 😀


About whitehatty

Computer Engineer and Scientist interested in Computer Security, Complex Networks, Math, Biology and Medicine. "Think Different" life style. Quake 3 Arena player. NERD by DNA.

Posted on April 28, 2012, in Mac OS X Tips & Tricks and tagged , , , , , , . Bookmark the permalink. 7 Comments.

  1. Thanks for the post! I was looking for something like this. EDID data is useful for getting the physical screen dimensions for calculating DPI. Imagine an app where the “actual size” of a document is 8.5×11″ as it should be 🙂

    Here’s another tip: rather than waiting two seconds for several megabytes of ioreg output to be generated and parsed, here’s a much faster version that only returns the display object. You can replace “display0” with other numbers representing any connected display (0 is always the “main” one).

    ioreg -lw0 -r -c “IODisplayConnect” -n “display0” -d 2 | grep …

  2. I tried both commands and it just drops down to the next line with 0 output. Any idea why this might be?

  3. I used the command line and I got back the name of the display and the serial number. Is there a command that returns the size / physical dimensions of the monitor?

  4. Do you know of a command that can parse the information out of the resulting EDID file?

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