lib/hidapi/engine.rb
def get_device(vendor_id, product_id, serial_number = nil, options = {})
      raise ArgumentError, 'vendor_id must be provided' if vendor_id.to_i == 0
      raise ArgumentError, 'product_id must be provided' if product_id.to_i == 0

      if serial_number.is_a?(Hash)
        options = serial_number
        serial_number = nil
      end

      klass = (options || {}).delete(:as) || 'HIDAPI::Device'
      klass = Object.const_get(klass) unless klass == :no_mapping

      list = enumerate(vendor_id, product_id, as: :no_mapping)
      return nil unless list && list.count > 0
      if serial_number.to_s == ''
        if klass != :no_mapping
          return klass.new(list.first)
        else
          return list.first
        end
      end
      list.each do |dev|
        if dev.serial_number == serial_number
          if klass != :no_mapping
            return klass.new(dev)
          else
            return dev
          end
        end
      end
      nil
    end
def get_device(vendor_id, product_id, serial_number = nil, options = {})
      raise ArgumentError, 'vendor_id must be provided' if vendor_id.to_i == 0
      raise ArgumentError, 'product_id must be provided' if product_id.to_i == 0

      if serial_number.is_a?(Hash)
        options = serial_number
        serial_number = nil
      end

      klass = (options || {}).delete(:as) || 'HIDAPI::Device'
      klass = Object.const_get(klass) unless klass == :no_mapping

      list = enumerate(vendor_id, product_id, as: :no_mapping)
      return nil unless list && list.count > 0
      if serial_number.to_s == ''
        if klass != :no_mapping
          return klass.new(list.first)
        else
          return list.first
        end
      end
      list.each do |dev|
        if dev.serial_number == serial_number
          if klass != :no_mapping
            return klass.new(dev)
          else
            return dev
          end
        end
      end
      nil
    end
def get_device ( vendor_id , product_id , serial_number = nil , options = { } ) raise ArgumentError , 'vendor_id must be provided' if vendor_id . to_i == 0 raise ArgumentError , 'product_id must be provided' if product_id . to_i == 0 if serial_number . is_a? ( Hash ) options = serial_number serial_number = nil end klass = ( options || { } ) . delete ( :as ) || 'HIDAPI::Device' klass = Object . const_get ( klass ) unless klass == :no_mapping list = enumerate ( vendor_id , product_id , as : :no_mapping ) return nil unless list && list . count > 0 if serial_number . to_s == '' if klass != :no_mapping return klass . new ( list . first ) else return list . first end end list . each do | dev | if dev . serial_number == serial_number if klass != :no_mapping return klass . new ( dev ) else return dev end end end nil end
Gets the first device with the specified vendor_id, product_id, and optionally serial_number.
Gets the first device with the specified vendor_id product_id and optionally serial_number .