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I was wondering if it is possible to set up profiles for my ubuntu laptop such that:

  • Disable apache/mysql/postgresql if running on batterymode
  • Disable all processes that are attempting to connect to the internet, if wireless is disabled.
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up vote 4 down vote accepted

I haven't come across the concept of such a profile in Ubuntu before, so I'm guessing that you can't do this right off the bat.

I could be wrong in assuming this, which would be nice. However, assuming there isn't an app to do this, and I had a strong desire to set this up, here's now I'd go about it.

I'm going to write this with the assumption you're running Gnome, since that's the environment I know best. The underlying process flow should still hold valid if you're in some other desktop or console environment.

Gnome lets you configure some aspects of system behaviour via System > Preferences > Power Management. This calls gnome-power-preferences, and it is enforced by the gnome-power-manager daemon process. From the gnome project page we know that gnome-power-manager depends on HAL to know if the laptop is operating on battery power.


So, fire up gnome-device-manager to see what HAL knows. Find the entry for battery. If you only see a summary tab, enable View > Device Properties. Yup, there are the two keys that we need: *battery.rechargeable.is_discharging* and *battery.rechargeable.is_charging*


Now we know what we need, we have to find out how to access this via the command line. Helpfully HAL comes with command-line tools to access this information. We first run

hal-device | less

and search for the *battery.rechareable.is_discharging* key. Back up so you get the block that details your battery info:

56: udi = '/org/freedesktop/Hal/devices/computer_power_supply_battery_BAT0'
  linux.subsystem = 'power_supply'  (string)
  info.capabilities = { 'battery' } (string list)
  info.subsystem = 'power_supply'  (string)
  info.product = 'DELL CC1546'  (string)
  info.udi = '/org/freedesktop/Hal/devices/computer_power_supply_battery_BAT0'  (string)
  battery.type = 'primary'  (string) = 'Li-ion'  (string) = 'lithium-ion'  (string)
  battery.model = 'DELL CC1546'  (string)
  battery.vendor = 'Panasonic'  (string) = 11100  (0x2b5c)  (int)
  battery.voltage.unit = 'mV'  (string) = 4700  (0x125c)  (int)
  battery.reporting.unit = 'mAh'  (string)
  battery.serial = '1076'  (string)
  battery.present = true  (bool)
  battery.voltage.current = 12712  (0x31a8)  (int)
  battery.reporting.rate = 2765  (0xacd)  (int)
  battery.is_rechargeable = true  (bool)
  battery.rechargeable.is_charging = true  (bool)
  battery.rechargeable.is_discharging = false  (bool)
  battery.reporting.current = 3407  (0xd4f)  (int)
  battery.reporting.last_full = 3963  (0xf7b)  (int)
  battery.charge_level.current = 37817  (0x93b9)  (int)
  info.parent = '/org/freedesktop/Hal/devices/computer'  (string)
  linux.sysfs_path = '/sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT0'  (string) = 52170  (0xcbca)  (int)
  battery.charge_level.percentage = 85  (0x55)  (int)
  battery.remaining_time = 723  (0x2d3)  (int)
  battery.charge_level.rate = 30691  (0x77e3)  (int)
  battery.charge_level.last_full = 43989  (0xabd5)  (int)
  info.category = 'battery'  (string)
  linux.hotplug_type = 2  (0x2)  (int)

Note the udi of the device. Now, query the property you want using the hal-get-property command:

$ hal-get-property --udi /org/freedesktop/Hal/devices/computer_power_supply_battery_BAT0 --key "battery.rechargeable.is_discharging"

Now we know how to access the battery status, stick this in a daemon-like script. Below is a basic template that takes the polling interval as the first parameter. You can fancy it up with error-checking and other nice-to-have constructs at leisure:

#!/usr/bin/env perl

my ($sleep_duration) = @ARGV;
print "Sleep:$sleep_duration\n";

        my $status = qx(hal-get-property --udi /org/freedesktop/Hal/devices/computer_power_supply_battery_BAT0 --key "battery.rechargeable.is_discharging");
        if ($status =~ /true/)
                print "On battery power\n";
                # shut down apache
                # shut down mysql
                # shut down postgresql

        sleep $sleep_duration;
} while (true);

Within the script, you should use the start-up scripts to cleanly shut down mysql etc

sudo /etc/init.d/mysqld stop

How can we improve on this? Once you have run this for a while and ironed out all the kinks, make this a service that starts up at boot. Check this answer here for instructions on adding a script to start automatically at boot-up.

If you decide not to do this, check this question for instructions on how to let this script execute commands that require root permissions.

I realize I have only answered one portion of your question, but you should be able to incorporate the wireless section in similar fashion. Use HAL to understand when wireless is disabled.

I'm not exactly certain how you check and disable all processes that try to connect to the net, but the following commands might help you with that task:

# list all processes using port 80
lsof -i tcp:80

#list programs connected via tcp 
#include -u to include udp connections
sudo netstat -ntp
share|improve this answer
This might just be the best answer I've ever seen on any of the Stack overflow sites. – Allain Lalonde Aug 28 '09 at 19:01
This is great! There are so many uses for this example you provided. A script that can access attributes from the HAL and react accordingly has many possibilities. Thanks... – Matt Cofer Aug 28 '09 at 19:03
Thank you so much, You are purely Awesome – dassouki Aug 29 '09 at 13:49

laptop-mode-tools can do what you're asking for.

       The  start-stop-programs  module  allows  you to start or stop programs
       when the computer switches to a different power state.

                 If this option is enabled, laptop mode tools  will  automati‐
                 cally  start  and stop daemons or other programs for you. The
                 actual   configuration   of   which   daemons   are   to   be
                 stopped/started is done by placing links to the daemons’ init
                 scripts in the following directories:






                 As you have probably guessed, the directories of the form "X-
                 stop-daemons" should contain init scripts of daemons that you
                 want stopped in mode X, while the directories of the form "X-
                 start-daemons"  should  contain  init scripts of daemons that
                 you want started in mode X. Of course, it is possible to  put
                 in  your  own handling of modes as well: the only requirement
                 on the scripts in the directories is  that  they  handle  the
                 "start" and "stop" commands, like init scripts usually do.

                 The  ordering  of  the  script handling is as follows. When a
                 mode is entered, the actions of the previous mode are undone,
                 in  reverse  order.  This means that if the previous mode had
                 done "daemon1 stop", "daemon2 stop" and "daemon3 start", then
                 the  undoing actions will be "daemon3 stop", "daemon2 start",
                 "daemon1 start". After that, the  stop-scripts  for  the  new
                 mode  are  called,  and  then  the  start-scripts are called.
                 Please note that  there  is  no  detection  of  commonalities
                 between  modes at this point, i.e., if the mode you’re coming
                 from and the mode you’re going to both specify that a  daemon
                 "X"  should  be  stopped,  then the daemon will be un-stopped
                 (that is, started) while leaving the previous mode, and  then
                 stopped again.







                 These  options allow you to stop services (through their init
                 scripts) in certain power states. Specify  a  space-separated
                 list  of  service names in these options.  These services are
                 started/stopped together with the files from the  directories
                 mentioned above.

It is possible to disable it's main function (spinning down HDD) from config file, it will still run other actions.

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You can use this command to stop or start services :

sudo /etc/init.d/'preferred services' stop|start|restart
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can you provide a more through example, or perhaps a sample bash script ? – dassouki Aug 28 '09 at 17:27
sudo /etc/init.d/apache2 restart #restart apache webserver – SjB Aug 29 '09 at 7:26

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