sitdown (or standup) with nvidia proprietary driver

gistfile1.sh

#!/bin/bash

if glxinfo | grep -q 'NVIDIA Corporation'; then
    case /$0 in
        */sitdown) xrandr -s 1 ;;
        */standup) xrandr -s 0 ;;
    esac
else
    hdmi=HDMI-1
    dvi=DVI-D-1
    case /$0 in
        */sitdown) xrandr --output $hdmi --auto ; xrandr --output $dvi --off ;;
        */standup) xrandr --output $dvi --auto ; xrandr --output $hdmi --off ;;
    esac
fi

xorg.conf

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "1"
    Option         "metamodes" "DFP-0: nvidia-auto-select +0+0, DFP-1: NULL; DFP-0: NULL, DFP-1: nvidia-auto-select +0+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection