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howtos:check_battery_state_with_bash_script [d/m/Y H:i] (current)
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 +====== Battery state script ======
 +The idea with this script is to check whether a server running on a laptop has lost its power source and needs to shutdown nicely.
 +===== Prerequisite =====
 +I use the utility called "​acpi"​ to easily draw out the required values. You could also get them directly from /proc but I'm lazy :-)
 +Install acpi with this command:
 +sudo apt-get install acpi
 +===== The script =====
 +The script is very simple and I've put some comments into it to clarify what I'm doing.
 +# Check if we're running on battery - the output will contain the word "​Discharging"​ if we are 
 +# and generate one line thus putting the value "​1"​ into the variable $state ​
 +state=`acpi -b|grep Discharging| wc -l`
 +# Next we retract the percentage value of remaining power
 +procent=`acpi -b|awk -F ", " '​{print $2}'​|sed -e '​s/​\%//​g'​`
 +# If the power value is below 10% of battery capacity and we're running without power
 +# we shutdown the server
 +if [ $procent -lt 10 -a $state -eq 1 ]
 +        logger "​Critical Low Power level - Shutting Down!"
 +        sleep 2
 +        halt
howtos/check_battery_state_with_bash_script.txt · Last modified: d/m/Y H:i (external edit)