Script for switching laptop displays (see http://westmarch.sjsoft.com/2012/11/laptop-display-switcher/)

simple-dual-display

#!/bin/bash
target_displays="$1"

VGA=VGA-0
LVDS=LVDS-0

if [[ "$target_displays" == "auto" || "$target_displays" == "" ]]
  then
    xrandr_output="`xrandr -q`"
    vga_connected=`echo "$xrandr_output" | grep "^$VGA " | cut -d' ' -f2`
    lvds_connected=`echo "$xrandr_output" | grep "^$LVDS " | cut -d' ' -f2`
    target_displays="external"
    [ "$vga_connected" != "connected" ] && target_displays="laptop"
    echo auto-selected target display "$target_displays"
  elif [[ "$target_displays" == "toggle" ]]; then
    xrandr_output="`xrandr -q`"
    vga_connected=`echo "$xrandr_output" | grep "^$VGA " | cut -d' ' -f2`
    lvds_connected=`echo "$xrandr_output" | grep "^$LVDS " | cut -d' ' -f2`
    if [ "$vga_connected" != "connected" ];
      then
        target_displays="laptop"
        echo vga not connected - displaying on $target_displays
      else
        vga_settings=`echo "$xrandr_output" | grep "^$VGA " | sed 's/(.*$//' | cut -d' ' -f3`
        lvds_settings=`echo "$xrandr_output" | grep "^$LVDS " | sed 's/(.*$//' | cut -d' ' -f3`
        # cycle through laptop, external, laptop+external
        [ "$vga_settings" == "" ] && [ "$lvds_settings" != "" ] && target_displays=external # when laptop only
        [ "$vga_settings" != "" ] && [ "$lvds_settings" == "" ] && target_displays=both # when external only
        [ "$vga_settings" != "" ] && [ "$lvds_settings" != "" ] && target_displays=laptop # when both on
        echo auto-selected target display "$target_displays"
      fi
  fi

if [[ "$target_displays" == "laptop" ]]
  then
    echo turning VGA off
    xrandr --output $VGA --off
    echo turning LVDS on auto
    xrandr --output $LVDS --auto
  elif [[ "$target_displays" == "2" || "$target_displays" == "both" ]]; then
    echo turning VGA on to the right of LVDS
    xrandr --output $VGA --right-of $LVDS --auto
    echo turning LVDS on to the left of LVDS
    xrandr --output $LVDS --left-of $VGA --auto
  elif [[ "$target_displays" == "external" ]]; then
    echo turning LVDS off
    xrandr --output $LVDS --off
    echo turning VGA on auto
    xrandr --output $VGA --auto
  else
    echo unknown option "$@"
    exit 1
  fi
xrandr_output="`xrandr -q`"
vga_settings=`echo "$xrandr_output" | grep "^$VGA connected" | sed 's/(.*$//' | cut -d' ' -f3`
lvds_settings=`echo "$xrandr_output" | grep "^$LVDS connected" | sed 's/(.*$//' | cut -d' ' -f3`
vga_size=${vga_settings%%+*}
lvds_size=${lvds_settings%%+*}
vga_offset=${vga_settings#*x*+}
lvds_offset=${lvds_settings#*x*+}
set | egrep '^(vga|lvds)'

echo done