touchpad-activator

#!/bin/bash

####################################################################################################
##
## touchpad-activator
##
## Utility script which uses xinput to extract information on the internal touchpad and allows
## to change its enabled status. Please note that this script will not work properly if the
## touchpad device of the XPS (2015-build) uses PS2 instead of the I2C bus. This is indeed
## the case if 'xinput --list' shows an entry like this 'DLL0665:01 06CB:76AD UNKNOWN' and
## an entry containing the text "PS2 touchpad". In this case, you have to blacklist the PS2 mode
## by adding the line 'blacklist psmouse' to /etc/modprobe.d/blacklist.conf and executing
## "sudo update-initramfs -u".
##
## This script logs its activity to $LOG_FILE.
##
####################################################################################################

LOG_DIRECTORY="/home/$USER/.touchpad-activator"
LOG_FILE="$LOG_DIRECTORY/touchpad-activator.log"

TOUCHPAD_DEVICE_PATTERN="DLL0665"
TOUCHPAD_DEVICE_ID=`xinput | grep $TOUCHPAD_DEVICE_PATTERN | cut -d'=' -f2 | cut -f2 --complement`
TOUCHPAD_IS_ENABLED=`xinput list-props $TOUCHPAD_DEVICE_ID | grep "Device Enabled" | cut -d':' -f2 | tr -d '[[:space:]]'`

function create_directory_if_nonexisting
{
	if [ ! -d $1 ];
	then
		mkdir $1
		chmod +rw $1
	fi
}

function init_log_file
{
	touch $LOG_FILE
}

function log
{
	echo $1 >> $LOG_FILE
}

function set_enabled_status
{
	xinput --set-prop $TOUCHPAD_DEVICE_ID "Device Enabled" $1
	log "[INFO  ] Enabled status for device $TOUCHPAD_DEVICE_ID has been set to $1."
}

function disable_touchpad
{
	set_enabled_status 0
}

function enable_touchpad
{
	set_enabled_status 1
}

function toggle_touchpad
{
	if [ $TOUCHPAD_IS_ENABLED -eq 0 ]
	then
		enable_touchpad
	else
		disable_touchpad
	fi
}

function status
{
	echo "Touchpad Device ID: "$TOUCHPAD_DEVICE_ID
	if [ $TOUCHPAD_IS_ENABLED -eq 0 ]
	then
		echo "Touchpad Status   : Off"
	else
		echo "Touchpad Status   : On"
	fi
}

function validate
{
	case $TOUCHPAD_DEVICE_ID in
		''|*[!0-9]*)
			log "[ERROR] Device ID '$TOUCHPAD_DEVICE_ID' is not a number."
			exit -1
			;;
	esac

	case $TOUCHPAD_IS_ENABLED in
		''|*[!0-9]*)
			log "[ERROR] Unable to read status for touchpad device with ID '$TOUCHPAD_DEVICE_ID'."
			exit -1
			;;
	esac
}

create_directory_if_nonexisting $LOG_DIRECTORY
init_log_file

validate

if [ -z "$1" ]
then
	toggle_touchpad
else

	case $1 in
		on)
			enable_touchpad
			;;
		off)
			disable_touchpad
			;;
		status)
			status
			;;
		*)
			status
	esac
fi