Hack and / - Lightning Hacks Strike Twice

My laptop doubles as a tablet, and even though I don't use the tablet mode very often, when I do use it, I like to be able to rotate the screen around to portrait mode and back. Now, dock applications exist that can do this with a few clicks, and I always could just try to remember the right xrandr commands, but instead, I wrote a little script that I then bound to one of the hardware buttons on my laptop display. Each time I press the button, it runs the script and rotates the screen another 90 degrees.

The key to the script is to keep track of your current orientation. When xrandr rotates, it rotates only left, right, inverted or normal, so if you already are rotated to the left and rotate left again, it won't change. To accomplish this, I just write the current orientation to a temporary file. Listing 1 shows the full script.

#!/bin/sh

export ORIENTATION=`cat /tmp/.orientation`

if [ $ORIENTATION -eq "90" ]; then
        xrandr --auto
        xrandr --output LVDS --rotate inverted 
        echo 180 > /tmp/.orientation
        echo "180" | osd_cat --shadow=2 --align=center \
        --pos=bottom --color=green --delay=2 \
        --font=lucidasanstypewriter-bold-24 \
	--offset 40 &
elif [ $ORIENTATION -eq "180" ]; then
        xrandr --auto
        xrandr --output LVDS --rotate left 
        echo 270 > /tmp/.orientation
        echo "270" | osd_cat --shadow=2 --align=center \
        --pos=bottom --color=green --delay=2 \
        --font=lucidasanstypewriter-bold-24 \
        --offset 40 &
elif [ $ORIENTATION -eq "270" ]; then
        xrandr --output LVDS --rotate normal 
        echo "Normal" | osd_cat --shadow=2 --align=center \
        --pos=bottom --color=green --delay=2 \
        --font=lucidasanstypewriter-bold-24 \
        --offset 40 &
        echo 0 > /tmp/.orientation
else
        xrandr --auto
        xrandr --output LVDS --rotate right 
        echo 90 > /tmp/.orientation
        echo "90" | osd_cat --shadow=2 --align=center \
        --pos=bottom --color=green --delay=2 \
        --font=lucidasanstypewriter-bold-24 \
        --offset 40 &
fi

Notice in Listing 1 that I also added an echo piped to osd_cat. This is optional and just displays the current orientation on my screen. If you want to use this, be sure you have the osd_cat utility (it's included with the xosd-bin package in Debian and Ubuntu). The way the script is set up, it will run through each of the orientations in order before it goes back to normal. Because the temporary file will be deleted any time the machine reboots, I made sure to set the default mode to rotate 90 degrees.