autohiberd

autohiberd

#!/bin/sh

os="$(uname -s | tr '[:upper:]' '[:lower:]')"
bat_percent_to_hiber=5

ac_stat()
{
	#  description: get status of ac power availability.

	ac_stat=
	os="$(uname -s | tr '[:upper:]' '[:lower:]')"

	case "${os}" in
		linux)
			ac_stat=$(cat /sys/class/power_supply/AC/online)
			;;
		*)
			return 1
	esac

	echo "${ac_stat}"
	return 0
}

bat_percent()
{
	#  description: get percentage of battery power availability.
	#
	#  math formula to calculate percentage of battery power
	#  avaiability when more than one battery is present on system:
	#  ( bat0 + bat1 + ... ) / 2

	bat_cap_i=    #  power capacity of individual batteries
	bat_cap_sum=  #  sum of power capacity of all individual batteries
	bat_cap_per=  #  percentage of total battery power availability
	os="$(uname -s | tr '[:upper:]' '[:lower:]')"

	case "${os}" in
		linux)
			bat_cap_i="$(cat /sys/class/power_supply/BAT*/capacity)"
			;;
		*)
			return 1
	esac

	if [ "$(echo "$bat_cap_i" | wc -w)" -gt 1 ]
	then
		bat_cap_sum="$(echo ${bat_cap_i} | tr ' ' '+' | bc)"
		bat_cap_per="$(echo ${bat_cap_sum}/2 | bc)"
	else
		bat_cap_per="${bat_cap_i}"
	fi

	echo "${bat_cap_per}"
	return 0
}

while :
do
	bat_percent > /dev/null 2>&1 || ac_stat > /dev/null 2>&1 || {
		printf '%s: unsupported platform\n' "$(basename "$0")" >&2
		exit 2
	}

	if [ "$(bat_percent)" -le ${bat_percent_to_hiber} ] && [ "$(ac_stat)" -eq 0 ]
	then
		case "${os}" in
			linux)
				if [ -f /usr/lib/systemd/systemd ]
				then
					systemctl hibernate
					sleep 120
				fi
				;;
		esac
	fi	

	sleep 2
done

<<0
	autohiberd
	==========
	A POSIX script that hibernates a system when the following conditions are met:
	
	- No AC power connected.
	- Low availability of battery power.
	
	In the case of (systemd) Linux support, no equivalent to OpenBSD's apmd exists,
	hence why this program was originally created.

	Licensing (MIT)
	---------------
	Copyright (c) 2022 Steven Peguero
	
	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:
	
	The above copyright notice and this permission notice shall be included in all
	copies or substantial portions of the Software.
	
	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	SOFTWARE.
0