auto-hibernate script and systemd service

auto-hibernate

#!/usr/bin/env bash

print_usage() {
	echo "	Usage: $0 [upper-threshold]"
}

if [ -z $1 ];
then
	echo "ERROR: upper threshold should be specified"
	print_usage
	exit 1
fi

battery_level=`acpi -b | cut -d ' ' -f 4 | grep -o '[0-9]*'`
battery_state=`acpi -b | cut -d ' ' -f 3 | grep -o '[a-zA-Z]*'`

# can it cause i18n issue??
if [ $battery_state != "Discharging" ];
then
	# no need to continue
	exit 0
fi

echo "current battery level: $battery_level%"

if [ $battery_level -le $1 ];
then
	echo "Battery lower than $1%. Currently at: $(battery_level)%, hibernating"
	/usr/bin/systemctl hibernate
fi

auto-hibernate.service

# file /etc/systemd/system/auto-hibernate.service
[Unit]
Description=Run the auto hibernate script every 5 minutes

[Service]
Restart=always
RestartSec=5m
ExecStart=/usr/bin/auto-hibernate 15

[Install]
WantedBy=multi-user.target