This blog started out as an install log of RedHat 9 on a Compaq Presario 2538cl laptop (linuxpresario.blogspot.com) . However, I soon started to include little logs to myself when I made configuration changes to software, etc. So, I've moved it over to our domain, and changed its name to Linux Log. Here you will find some tips & tricks related to Linux configuration on a laptop, as well as software related things that I run into. I log here things that worked for me, of course, your mileage may vary.

Any questions/comments? E-mail me at linux_atsign_boshoff|za|net.

Power Management

Hibernate using acpid

October 29, 2003

I've written a little script to hibernate when I hit the power button. On my laptop, everytime you hit the power button it registers two power button events in the acpid log. So I needed to work around it a little, to prevent two consecutive suspend-resume cycles everytime I hit the power. In /etc/acpi/events I have a script "power", which has:

# This is a sample ACPID configuration

event=button[ /]power
#action=sudo /usr/local/sbin/hibernate
action=/etc/acpi/events/start_suspend.sh %e

The %e passes the full entry of the acpi event to the script. I'm not using this yet. Here's the start_suspend.sh script:

#!/usr/bin/perl
$DIR = "/etc/acpi/events";

$counter=`cat $DIR/buttoncounter | bc`;

if ( $counter == 0 ) {
# First button event, suspend computer

$out = `echo 1 > /etc/acpi/events/buttoncounter`;
$out = `sudo /usr/local/sbin/hibernate` || die "Unable to start hibernating: $!";

} else {
# Second button event, insert usb controller module

$out = `echo 0 > /etc/acpi/events/buttoncounter`;

}

What's nice about it is that it makes it easy to run additional things upon resume. I don't need this yet, but I can see how sometimes one would want to do this. As you can tell, it's basically a work-around for my dual-acpi-event-when-power-button-is-pressed problem.

Software Suspend Setup

October 22, 2003

Installed the suspend.sh script today by downloading it from the swsusp mailing list. (Check out the software suspend site).

Then ran suspend.sh --install. Also, since I'd like to be able to suspend without becoming root, I edited /etc/sudoers, and added:

Host_Alias LOCALHOST=localhost,teleo.che.udel.edu
ALL LOCALHOST=NOPASSWD: /usr/local/sbin/hibernate *

It appears to work right off the bat. Woa! It's pretty cool, and definitely cuts down on boot-up and shutdown time. It's really cool not to have to close all windows before turning off the laptop either. I hooked up software suspension to be activated when I press the power button on the laptop: File /etc/acpi/events/power:

event=button[ /]power
action=sudo /usr/local/sbin/hibernate

acpid Installed

June 03, 2003

Installed the acpid utility, which looks for power events and issue commands that you specify. You can get this utility at the acpid event daemon website. Right now, I only have one event, which basically shuts down the computer when you press the power button. I'd like more creative options here, but haven't really thought of any. Let me know if you come up with something useful.

I have a file called power in /etc/acpid/events that contains:

event=button[ /]power
action=shutdown -t 15 -h now "%e"