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I am using 2 screens, and wish to invert the colors on both of them without using compiz (I'm using gnome shell).

I can use xcalib -invert -alter as suggested in this question, but it only inverts one of the screens. Is there a way to specify both of them, or even which of them, using xcalib? Is there another way?

With xcalib, you can specify which screen to alter with the -d (-display) or -s (-screen) options, but alas, X seems to be aware of just one screen: when I use the w command I only see one (the usual ":0")

ps: this question was originally posted by k0pernikus as a comment here.


This is the output of xrandr:

Screen 0: minimum 320 x 200, current 3200 x 1200, maximum 8192 x 8192
VGA-0 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 376mm x 301mm
1280x1024 60.0*+ 75.0
1280x960 60.0
1152x864 75.0
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
640x480 72.8 75.0 66.7 60.0
720x400 70.1
DVI-0 connected 1920x1200+1280+0 (normal left inverted right x axis y axis) 518mm x 324mm
1920x1200 60.0*+
1600x1200 60.0
1280x1024 75.0 60.0
1280x960 60.0
1152x864 75.0
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
640x480 72.8 75.0 66.7 60.0
720x400 70.1

I can use -s DVI-0 or -s VGA-0, but they do the same as -s :0

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I have the same problem. There are some commands in my ticket that may help you add some information to your ticket. Lets see if we have a similar setup: unix.stackexchange.com/questions/118477/… –  jcalfee314 Mar 10 '14 at 15:46
I have a work-around... It got more complicated with Ubuntu 14.04. Basically, I invert once (one screen) using -s 0 the I unplug and re-plug my HDMI cable. Then I invert again (same screen same command).. Finally I invert -s HDMI-0.. and both monitors are inverted. I can then toggle one of them with the -s 0. So, aside from this being so ridiculous this holds me over. –  jcalfee314 Aug 26 '14 at 13:59
lol! I once collected a data set from a dynamic website by putting a weight on the 'page-down' key, waiting till memory was all filled up, then hitting ctrl-s (very carefully - the machine was almost completely unresponsive!) –  drevicko Aug 26 '14 at 15:40

1 Answer 1

The display ids in X follow the form :<screen>.<display>. Contrary to intuition, all the monitors in a multiple-monitor setup share a <screen>, but have varying <display>. The screen "first" in the setup is :0.0, and others are :0.1, :0.2, etc. The final command is xcalib -invert -alter -display :0.1

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nice try, but on :0.0 is recognized (same screen as :0), the others I tried all said something like Error - Can't open display :0.1 –  drevicko Apr 17 '14 at 1:52
Could you try :1, and the like? –  user269370 Apr 17 '14 at 3:15
no luck ): Only thing I can find that works is :0 or :0.0 (which are the same monitor). I wonder if Gnome is not playing fair with X?? –  drevicko Apr 17 '14 at 3:31
hmmmm... What is the output of xrandr? –  user269370 Apr 17 '14 at 3:41
'Can't open display' ... that's it! Gnome is doing somthing these tools don't expect! –  drevicko Apr 17 '14 at 8:34

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