Change Main Display via Keyboard Shortcut or command line in Mac OS X

Question

I am using OS X 10.11.3 (15D21) with one monitor and one projector.

Mirroring is turned off.

Mac OS X has an option to switch the main display (the display that has the upper menu) via the System Preferences, as depicted in the attached screenshot:

Basically to switch one drags the little menu bar from one side to the other.

My question is: Is there a way to accomplish this switch via the keyboard or better yet as a command from the Terminal?

Solution 1

hmscreens work great. Here's a sample command line to swap monitors:

hmscreens -setMainID `hmscreens -info | grep "Screen ID:" | head -2 | tail -1 | sed 's/[^0-9]*//g'`

Solution 2

The free terminal tool I wrote, displayplacer, allows you to configure the main display via scripts/hotkeys.

Configure your screens how you like, drag the "white bar" to your primary screen in the macOS system settings, and then execute displayplacer list. It will output the command to run to put your screens in their current configuration. The screen with origin:(0,0) is the main display with the "white bar". Run this terminal command through a script or bind to a hotkey using Automator/BetterTouchTool/etc.

This example makes the left screen the primary monitor. Execute a similar command whenever your machine randomly chooses the wrong primary display. displayplacer "id:<leftScreenId> res:1920x1080 scaling:on origin:(0,0) degree:0" "id:<rightScreenId> res:1920x1080 scaling:on origin:(1920,0) degree:0"

Also available via Homebrew brew tap jakehilborn/jakehilborn && brew install displayplacer

Comments

[Simon Sheehan]

What is your goal? To have the dock on both screens?

[PPR]

My goal is to switch the "main" display (the one that has all the windows I've been working with).

[linuxdev2013]

What you want is to keybind that. look in the keyboard settings and under hotkeys select the display management app and set a keybinding to it and save.

[Scott - Слава Україні]

While your program may solve the OP’s problem, we prefer answers that explain how a piece of software can be used to achieve the desired effect.

[Jake Hilborn]

@Scott I updated my answer to address your feedback.

[Admin]

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