Module: LinuxStat::Battery

Defined in:
lib/linux_stat/battery.rb

Overview

Shows various battery related information of the current system.

Constant Summary collapse

PATH = 
"/sys/class/power_supply/BAT0".freeze

Class Method Summary collapse

Class Method Details

.charge ⇒ Object

Returns the charge of the battery.

If the battery is not present or the information is not available, it will return nil.



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# File 'lib/linux_stat/battery.rb', line 107

def charge
  @@charge_now_file ||= File.join(PATH, 'charge_now')
  @@charge_full_file ||= File.join(PATH, 'charge_full')

  @@charge_now_readable ||= File.readable?(@@charge_now_file) && File.readable?(@@charge_full_file)
  return nil unless @@charge_now_readable

  charge_now = IO.read(@@charge_now_file).to_i
  charge_full = IO.read(@@charge_full_file).to_i

  percentage = charge_now.*(100).fdiv(charge_full)
  percentage > 100 ? 100.0 : percentage < 0 ? 0.0 : percentage
end

.charge_full_design_wh ⇒ Object

Returns the charge full design WH of the battery as Integer However if the info isn’t available or there’s no BAT0 in the system, this will return nil



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# File 'lib/linux_stat/battery.rb', line 124

def charge_full_design_wh
    # voltage min design
    @@vmd_f ||= File.join(PATH, 'voltage_min_design'.freeze)
    v_m_d = File.readable?(@@vmd_f) ? IO.read(@@vmd_f).to_i : nil

    # charge full design
    @@cfd_f ||= File.join(PATH, 'charge_full_design'.freeze)
    c_f_d = File.readable?(@@cfd_f) ? IO.read(@@cfd_f).to_i : nil

    if v_m_d && c_f_d
      v_m_d.fdiv(1_000_000).*(c_f_d.fdiv(1_000_000)).round(2)
    else
      nil
    end
end

.charge_full_wh ⇒ Object

Returns the charge full WH of the battery as Integer However if the info isn’t available or there’s no BAT0 in the system, this will return nil



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# File 'lib/linux_stat/battery.rb', line 143

def charge_full_wh
    # voltage min design
    @@vmd_f ||= File.join(PATH, 'voltage_min_design'.freeze)
    v_m_d = File.readable?(@@vmd_f) ? IO.read(@@vmd_f).to_i : nil

    # charge full
    @@cf_f ||= File.join(PATH, 'charge_full'.freeze)
    c_f = File.readable?(@@cf_f) ? IO.read(@@cf_f).to_i : nil

    if v_m_d && c_f
      v_m_d.fdiv(1_000_000).*(c_f.fdiv(1_000_000)).round(2)
    else
      nil
    end
end

.charging? ⇒ Boolean

Returns true if the battery is charging, false if the battery is not charging.

If the battery is not present or the information is not available, it will return nil.

Returns:

  • (Boolean) 


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# File 'lib/linux_stat/battery.rb', line 80

def charging?
  return nil if status.empty?
  %w(full charging unknown).each(&:freeze).include?(status.downcase)
end

.devices_stat ⇒ Object

A linux system can have multiple batteries. This method attempts to find all of them and return a Hash based on the availibility of the information.

This method is somewhat slower than other Battery module singleton methods. Because it does various checks and opens various files from /sys/

For example, a sample output can be like this (taken on a test system):

LinuxStat::Battery.devices_stat
=> {:AC=>{:type=>"Mains", :online=>1}, :BAT0=>{:model=>"DELL CYMGM77", :manufacturer=>"Samsung SDI", :type=>"Battery", :status=>"Full", :capacity=>100, :voltage_min_design=>11.4, :charge_full_design=>3.684, :charge_full_design_wh=>42.0, :voltage_now=>12.558, :charge_now=>2.087, :charge_now_wh=>26.21, :charge_full_wh=>23.79, :charge_percentage=>100.0}, :hidpp_battery_0=>{:model=>"Wireless Keyboard", :manufacturer=>"Logitech", :type=>"Battery", :status=>"Discharging", :online=>1}}

If you need info about lots of batteries, use this method. If the informations are not available, it will return empty Hash for each devices. If the system has no batteries, it will return an empty Hash.



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# File 'lib/linux_stat/battery.rb', line 186

def devices_stat
  h = {}
  Dir["/sys/class/power_supply/*/".freeze].tap(&:sort!).each do |x|
    # model name
    mn_file = File.join(x, 'model_name'.freeze).freeze
    model_name = File.readable?(mn_file) ? IO.read(mn_file).strip : nil

    # manufacturer
    m_f = File.join(x, 'manufacturer'.freeze).freeze
    manufacturer = File.readable?(m_f) ? IO.read(m_f).strip : nil

    # type
    t_f = File.join(x, 'type'.freeze).freeze
    type = File.readable?(t_f) ? IO.read(t_f).strip : nil

    # capacity
    c_file = File.join(x, 'capacity'.freeze).freeze
    capacity = File.readable?(c_file) ? IO.read(c_file).to_i : nil

    # voltage now
    vn_f = File.join(x, 'voltage_now'.freeze).freeze
    voltage_now = File.readable?(vn_f) ? IO.read(vn_f).to_i.fdiv(1_000_000) : nil

    # charge now
    cn_f = File.join(x, 'charge_now'.freeze).freeze
    charge_now = File.readable?(cn_f) ? IO.read(cn_f).to_i.fdiv(1_000_000) : nil

    # voltage min design
    vmd_f = File.join(x, 'voltage_min_design'.freeze).freeze
    v_m_d = File.readable?(vmd_f) ? IO.read(vmd_f).to_i.fdiv(1_000_000) : nil

    # charge full design
    cfd_f = File.join(x, 'charge_full_design'.freeze).freeze
    c_f_d = File.readable?(cfd_f) ? IO.read(cfd_f).to_i.fdiv(1_000_000) : nil

    # charge full
    cf_f = File.join(x, 'charge_full'.freeze).freeze
    charge_full = File.readable?(cf_f) ? IO.read(cf_f).to_i.fdiv(1_000_000) : nil

    # status
    s_f = File.join(x, 'status'.freeze).freeze
    status = File.readable?(s_f) ? IO.read(s_f).strip : nil

    # online
    o_f = File.join(x, 'online'.freeze).freeze
    online = File.readable?(o_f) ? IO.read(o_f).to_i : nil

    charge_percentage = if charge_now && charge_full
      charge_now.*(100).fdiv(charge_full).round(2)
    else
      nil
    end

    # full_charge_design (WH)
    c_f_d_wh =  if c_f_d && v_m_d
      v_m_d.*(c_f_d).round(2)
    else
      nil
    end

    c_n_wh = if voltage_now && charge_now
      voltage_now.*(charge_now).round(2)
    else
      nil
    end

    c_f_wh = if v_m_d && charge_full
      v_m_d.*(charge_full).round(2)
    else
      nil
    end

    ret = {}
    ret[:model] = model_name if model_name
    ret[:manufacturer] = manufacturer if manufacturer
    ret[:type] = type if type

    ret[:status] = status if status
    ret[:online] = online if online
    ret[:capacity] = capacity if capacity

    ret[:voltage_min_design] = v_m_d if v_m_d
    ret[:charge_full_design] = c_f_d if c_f_d
    ret[:charge_full_design_wh] = c_f_d_wh if c_f_d_wh

    ret[:voltage_now] = voltage_now if voltage_now
    ret[:charge_now] = charge_now if charge_now

    ret[:charge_now_wh] = c_n_wh if c_n_wh
    ret[:charge_full_wh] = c_f_wh if c_f_wh
    ret[:charge_percentage] = charge_percentage if charge_percentage

    h.merge!(File.split(x)[-1].to_sym => ret)
  end
  h
end

.discharging? ⇒ Boolean

Returns true if the battery is discharging, false if the battery is not discharging.

If the battery is not present or the information is not available, it will return nil.

Returns:

  • (Boolean) 


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# File 'lib/linux_stat/battery.rb', line 89

def discharging?
  return nil if status.empty?
  status.downcase == 'discharging'.freeze
end

.full? ⇒ Boolean

Returns true if the battery status if full, false if the battery status is not full.

If the battery is not present or the information is not available, it will return nil.

Returns:

  • (Boolean) 


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# File 'lib/linux_stat/battery.rb', line 98

def full?
  return nil if status.empty?
  status.downcase == 'full'.freeze
end

.manufacturer ⇒ Object

Returns the manufacturer of the battery.

If the battery is not present or the information is not available, it will return an empty String.



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# File 'lib/linux_stat/battery.rb', line 49

def manufacturer
  @@manufacturer_file ||= File.join(PATH, 'manufacturer')
  return ''.freeze unless manufacturer_readable?
  IO.read(@@manufacturer_file).tap(&:strip!)
end

.model ⇒ Object

Returns the model of the battery.

If the battery is not present or the information isn’t available it will return an empty String.



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# File 'lib/linux_stat/battery.rb', line 38

def model
  @@mn_file = File.join(PATH, 'model_name')
  return ''.freeze unless File.readable?(@@mn_file)

  IO.read(@@mn_file).tap(&:strip!)
end

.present? ⇒ Boolean

Returns true or false based on the presence of the battery.

Returns:

  • (Boolean) 


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# File 'lib/linux_stat/battery.rb', line 10

def present?
  @@present ||= Dir.exist?(PATH)
end

.stat ⇒ Object

Returns the details of the battery.

If the battery is not present it will return an empty Hash.



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# File 'lib/linux_stat/battery.rb', line 18

def stat
  st = status.downcase
  return {} unless present?

  {
    model: model,
    manufacturer: manufacturer,
    technology: technology,
    status: status,
    charge: charge,
    charging: %w(full charging unknown).each(&:freeze).include?(st),
    discharging: st == 'discharging'.freeze,
    full: st == 'full'.freeze,
  }
end

.status ⇒ Object

Returns the status of the battery. The status generally includes either of the full, charging, discharging and unknown states in most cases.

If the battery is not present or the information is not available, it will return an empty frozen String.



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# File 'lib/linux_stat/battery.rb', line 70

def status
  @@status_file ||= File.join(PATH, 'status'.freeze)
  return ''.freeze unless status_readable?
  IO.read(@@status_file).tap(&:strip!)
end

.technology ⇒ Object

Returns the technology of the battery.

If the battery is not present or the information is not available, it will return an empty String.



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# File 'lib/linux_stat/battery.rb', line 59

def technology
  @@technology_file ||= File.join(PATH, 'technology')
  return ''.freeze unless tech_readable?
  IO.read(@@technology_file).tap(&:strip!)
end

.voltage_now ⇒ Object

Returns the voltage of the battery as Integer However if the info isn’t available or there’s no BAT0 in the system, this will return nil



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# File 'lib/linux_stat/battery.rb', line 162

def voltage_now
  @@voltage_file ||= File.join(PATH, 'voltage_now'.freeze)
  @@voltage_readable ||= File.readable?(@@voltage_file)
  return nil unless @@voltage_readable

  IO.read(@@voltage_file, 16).to_f.fdiv(1000000)
end