a script to get some informations about your battery

knopwob · 2010-01-30 23:53:35

Hey there,

I wanted some informations about my battery in my screen caption. So i have written a small python script for that purpose. Maybe some of you can get some use out of this script, too.
I think, a simple example describes it best:
(i've named my script "battery")
--> battery "%S: %t at %r, health: %h"
charging: 3h,19m at 8W, health: 45%

So here it is:

#!/usr/bin/env python
import sys
#A simple script to get informations about your battery
#It takes a format string and substitutes some characters
#with informations from /proc/acpi/battery/BAT#/*
#
#I think, a simple example describes it best
#battery "%S: %t at %r, health: %h"
#becomes: discharging: 0h,23m at: 12W, health: 45%
#for a list of all substitutions see the dictionary "substitutions" 
#near the end of this code

settings = { "battery" : "BAT0"}
if len(sys.argv) != 2:
    print "ERROR: exactly one argument expected"
    sys.exit(1)

target_string = sys.argv[1]


def extractValue(battery_line):
    #this looks uglier than it is
    return int(battery_line.split(':')[1].strip().split(' ')[0].strip())

#many of the variables below won't be used, but it doesn't hurt to have them anyway

#extract informations from battery info file
batfile = open("/proc/acpi/battery/%s/info" % settings['battery'] )
for line in batfile:
    if 'present' in line:
        present = line.split(':')[1].strip()
    elif 'design capacity' in line:
        design_capacity = extractValue(line)
    elif 'last full capacity' in line:
        last_full_capacity = extractValue(line)
    elif 'battery technology' in line:
        battery_techology = line.split(':')[1].strip()
    elif 'design voltage' in line:
        design_voltage = extractValue(line)
    elif 'design capacity warning' in line:
        design_capacity_warning = extractValue(line)
    elif 'design capacity low' in line:
        design_capacity_low = extractValue(line)
    elif 'capacity granularity 1' in line:
        capacity_granularity_1 = extractValue(line)
    elif 'capacity_granularity_2' in line:
        capacity_granularity_2 = extractValue(line)
    elif 'model number' in line:
        model_number = line.split(':')[1].strip()
    elif 'serial number' in line:
        serial_number = line.split(':')[1].strip()
    elif 'battery type' in line:
        battery_type = line.split(':')[1].strip()
    elif 'OEM info' in line:
        OEM_info = line.split(':')[1].strip()
batfile.close()        

#extract informations from battery alarm file
batfile = open("/proc/acpi/battery/%s/alarm" % settings['battery'])
for line in batfile:
    if 'alarm' in line:
        alarm = extractValue(line)
batfile.close()

#extract informations from battery state file
batfile = open("/proc/acpi/battery/%s/state" % settings['battery'])
for line in batfile:
    if 'capacity state' in line:
        capacity_state = line.split(':')[1].strip()
    elif 'charging state' in line:
        charging_state = line.split(':')[1].strip()
    elif 'present rate' in line:
        present_rate = extractValue(line)
    elif 'remaining capacity' in line:
        remaining_capacity = extractValue(line)
    elif 'present voltage' in line:
        present_voltage = extractValue(line)

#Derive some informations
if charging_state == 'discharging':
    time_remaining = 1.00*remaining_capacity/present_rate
    #change time_remaining into a (hh,mm)tuple
    hours = 0
    while(time_remaining >= 1):
        hours += 1
        time_remaining -= 1
    minutes = int(time_remaining * 60)
    time_remaining = (hours, minutes)

elif charging_state == 'charging':
    time_remaining = 1.00*last_full_capacity/present_rate
    hours = 0
    while(time_remaining >= 1):
        hours += 1
        time_remaining -= 1
    minutes = int(time_remaining * 60)
    time_remaining = (hours, minutes)
else:
    time_remaining = ''

battery_health = (last_full_capacity/design_capacity)


#Create return string

#You can add your own substitutions into this dictionary.
#the value must be a string
substitutions = { 'S' : str(charging_state),
                  't' : "%sh,%sm" % (time_remaining[0], time_remaining[1]),
                  'R' : str(remaining_capacity),
                  'v' : str(present_voltage),
                  'V' : str(design_voltage),
                  'r' : str(int(present_rate/1000)) + 'W',
                  'h' : str(battery_health) + '%',
                  }
#The real substitution happens here
substitute_next = False
escaped = False
result = ""
for i in xrange(0,len(target_string)):
    if substitute_next:
        substitute_next = False
        if substitutions.has_key(target_string[i]):
            result += substitutions[target_string[i]]
        else:
            print "Can't parse your string"
            print "maybe you haven't escaped the '%' sign? Escape it with '\\%'"
            sys.exit(1)
    elif target_string[i] == '%' and not escaped:
        substitute_next = True
    else:
        escaped = False
        if target_string[i] == '\\':
            escaped = True
        else:
            result += target_string[i]

print result

I welcome every critic, suggestions and so on.

I hope my first post in this Forum may be usefull to someone out there

Krause · 2010-01-31 00:04:21

I've made something similar, but nowhere near as complex.

#!/bin/bash
while true; do
        cat /proc/acpi/battery/BAT0/state && sleep 1
        clear
done

For everything else, there's 'acpi -V'.

Edit: This is what happens when I run your script:

$ ./battery "%S: %t at %r, health: %h"
Traceback (most recent call last):
  File "./battery", line 62, in <module>
    alarm = extractValue(line)
  File "./battery", line 23, in extractValue
    return int(battery_line.split(':')[1].strip().split(' ')[0].strip())
ValueError: invalid literal for int() with base 10: 'unsupported'

Last edited by Krause (2010-01-31 00:06:20)

knopwob · 2010-01-31 00:34:04

damn, i haven't thought about using acpi. That could have saved about an hour of my lifetime

well, anyway. The script doesn't work for your machine, because my script expects something like this

alarm:   3098mWh

in BAT0/alarm
but yours seem to look more like

alarm: unsupported

But since you gave me a better way to get the information i want, i don't see a reason to fix my script
except someone else wants to use it.

Arch Linux

#1 2010-01-30 23:53:35

a script to get some informations about your battery

#2 2010-01-31 00:04:21

Re: a script to get some informations about your battery

#3 2010-01-31 00:34:04

Re: a script to get some informations about your battery

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