Shutdown Pressing Power Button

Prerequisites

First of all, make sure that button module is loaded (check the output of lsmod). If it is not, load it manually with modprobe and to load it automatically at boot time add it to your /etc/rc.conf MODULES array.

Note: Some machines only fire the power button acpi event after the power button is held down for some seconds, e.g. Thinkpads ~ 3 seconds.

First solution

If you want to shutdown your system by simply pressing the power button, do the following:

1. Install the acpid package and add acpid to the DAEMONS array in /etc/rc.conf.
2. Create a file in /etc/acpi/events/ named power with following content:

# /etc/acpi/events/power
# This is called when the user presses the power button

event=button/power (PWR.||PBTN)
action=/sbin/poweroff

To be able to test it, make sure the acpid daemon is started, see Daemon for instructions. To test it without actually shutting down, comment out the poweroff line and check your user/messages logs.

From now on, pressing the power button (lightly, not for a few seconds) should properly shutdown the system. Note that if you have hibernate configured and working you may want to change the last line with:

action=/usr/sbin/hibernate

If you are using a more sophisticated Window Manager, you should use its own shutdown call, so it would save its session etc.

KDE 3

Change the action in /etc/acpi/events/power to:

action=/opt/kde/bin/dcop --all-users --all-sessions ksmserver ksmserver logout 0 2 0

KDE 4

As of KDE 4.4, you can still use dcop as shown above.

Alternatively, you can use Template:Codeline:

1. Delete (or comment out) Template:Codeline.
2. Open System Settings.
3. Go to Advanced>>Power Management.
4. Select "Edit Profiles" and choose the current profile. (In KDE 4.4, the default profile is "Powersave.")
5. Select "Shutdown" as the action for "When power button is pressed."
6. Press Apply.

Note:

• With dcop and PowerDevil, the power button works only when KDE is running. Also, KDE needs to start from KDM (it probably also works when started from GDM). It does not work if you start KDE with a "startx" command.
• The PowerDevil configuration is per user. To configure the power button for other users, repeat these steps for each user's account.

Template:Box YELLOW

Xfce

For Xfce 4.4 change the action line to:

action=echo POWEROFF | /usr/lib/xfce4/xfsm-shutdown-helper

For Xfce 4.8 change the action line to:

action=echo POWEROFF | /usr/lib/xfce4/session/xfsm-shutdown-helper

Note: For a more robust solution (If you are facing frequent WM crashes or working on a sacrificial PC for developing or testing your software...), you should take a look at "/usr/src/linux/Documentation/sysrq.txt", which is a kernel facility for yielding you (the user...) the CPU so that it could be used for any rescue work.

Second solution

1. Install the acpid package and add acpid to the DAEMONS array in /etc/rc.conf.
2. Edit /etc/acpi/handler.sh:

...
case "$1" in
   button/power)
       #echo "PowerButton pressed!">/dev/tty5
       case "$2" in
           PWRF)   logger "PowerButton pressed: $2" 
		    /sbin/poweroff;;
           *)      logger "ACPI action undefined: $2" ;;
       esac
       ;;
...

To be able to test it, make sure the acpid daemon is started, see Daemon for instructions. To test it without actually shutting down, comment out the poweroff line and check your user/messages logs.