Linux Blog

Suspend Scripts for the Toshiba Tecra M2

Filed under: Quick Linux Tutorials,Shell Script Sundays — at 12:15 am on Sunday, March 30, 2008

As you may know if you are a regular reader I own a Toshiba Tecra M2. One of the things that annoyed me was I had to turn the brightness up every time my computer came out of standby mode. A fix for this is to adjust the brightness every time the computer comes out of standby mode.

The script is intended to be run under cron. I have mine set up to suspend after 5 minutes of the lid being closed.

if [ $(cat /proc/acpi/button/lid/LID/state | sed 's/state:      //') == "closed" ]; then
VAR=$(cat /proc/acpi/toshiba/lcd | sed 's/brightness:              //' grep -v levels);
sudo su -c "echo mem > /sys/power/state";
if [ $VAR -eq 1 ]; then
elif [ $VAR -eq 7 ]; then
if [ $ACTION == "ADD" ]; then
VAR=$(($VAR + 1));
VAR=$(($VAR - 1));
sudo su -c "echo brightness:$(echo $VAR) > /proc/acpi/toshiba/lcd";

I run this with the following cron entry:

*/5 * * * * sh

The script first checks the current brightness. If the brightness is currently 1 or 7 it adjusts the mathematic operation so that when the laptop is opened the brightness is adjusted. Basically if the brightness is one, it adds one. If the brightness is 7 or any other value it subtracts one. This is currently working out quite well for me. I don’t know how useful this is to any body else, unless you happen to have a Toshiba that is doing the same thing but it should give you a good overall idea of how to perform basic mathematic operations in bash.