Check battery status to notify unplug. Tested on my notebook, Dell mini 12.

check-plug.go

package main

import (
	"fmt"
	"log"
	"os"
)

const (
	PATH_B_STAT = "/sys/class/power_supply/BAT1/status" // Full or Discharging
	PATH_E_NOW  = "/sys/class/power_supply/BAT1/energy_now"
	PATH_E_FULL = "/sys/class/power_supply/BAT1/energy_full"
)

func readIntFromFile(path string) (n int) {
	f, err := os.Open(path)
	if err != nil {
		log.Fatal(err)
	}
	if _, err := fmt.Fscanf(f, "%d", &n); err != nil {
		log.Fatal(err)
	}
	return
}

func main() {
	full := readIntFromFile(PATH_E_FULL)
	curr := readIntFromFile(PATH_E_NOW)

	p := curr * 100 / full
	fmt.Println(p)

	f, err := os.Open(PATH_B_STAT)
	if err != nil {
		log.Fatal(err)
	}

	var stat string
	if _, err := fmt.Fscanln(f, &stat); err != nil {
		log.Fatal(err)
	}

	if stat == "Discharging" {
		os.Exit(1)
	}
}