displays

displays is a simple commandline tool to configure displaymodes and mirroring in Mac OS X.

It is easily installed via Python's setuptools.

$ sudo easy_install displays
   [...]

Or run sudo python setup.py install in the source code folder.

Configuring display modes

To list the online displays and its displaymodes, run displays list.

    $ displays list
    #0 display 69676864 main online active builtin
      1280 x 800            
      1152 x 720            
      1024 x 768            
    * 1024 x 768  Stretched 
      1024 x 640            
       800 x 600            
       800 x 600  Stretched 

To set the mode of a display, run display set.

    $ displays set 1280x800

If several modes match the same modeline, you can pick one using the --choose option.

    $ displays set 1024x
    More than one mode matches:

    0  1024 x 768          
    1  1024 x 768 Stretched
    2  1024 x 640          

    Refine the request or use `--choose n' to pick canididate n
    $ displays set 1024x --choose 2

Displaymodes that Mac OS X thinks are not suitable for the desktop GUI are hidden. Use --all (-a) to involve them.

To change the mode of another display, use the option --display. Example:

    $ displays set 1280x1024@75 --display 1

Changes persist for the duration of the loginsession. To apply the changes for every session, use the --permanently flag.

displays can also automatically configure the displaymodes as it thinks is best:

    $ displays auto

Basically, displays will pick the top modes listed by displays list.

Configuring mirroring

A bunch of displays that show the same image are called a mirroring set. If you want display #0 to be in the same mirroring set as display #1, run:

    $ displays mirror --display 0 --master 1

If you do not specify --display or --master, the master display and the first other display will be mirrored.

To remove display #1 from a mirroring set, run:

    $ displays unmirror --display 1

If you do not specify --display then the main display will be unmirrored if it is in a display set. Otherwise another display in a mirroring set will be unmirrored.

Hidden refresh rate, bit depth and hardware flags

If all listed displaymodes have the same refresh rate, the refresh rates are hidden. The same goes for the bit depth. Hardware flags (for instance: Stretched) are only shown when required to differentiate modes.

To override this behaviour, use --full-modes.