USBSerialからSMSを送信します（ruby2.4.0）

attest.rb

#!/usr/bin/env ruby

require 'serialport'

class AtCommand
  def self.fin_proc
    proc { @sp.close }
  end

  def initialize
    @sp = SerialPort.new('/dev/sms')
    @sp.set_modem_params(115_200, 8, 1, 0)
    ObjectSpace.define_finalizer(self, self.class.fin_proc)
  end

  def ok?
    sleep(0.5)
    line = @sp.readpartial(1024).delete("\r").split("\n")
    puts "<< #{line}"
    line[-1] == 'OK'
  end

  def prompt?
    sleep(0.5)
    line = @sp.readpartial(1024).delete("\r").split("\n")
    line[-1] == '> '
  end

  def sent?
    sleep(5)
    line = @sp.readpartial(1024).delete("\r").split("\n")
    puts "<< #{line}"
    line[1] != 'ERROR'
  end

  def send(msg)
    @sp.write(msg)
    puts ">> #{msg}"
  end

  def pack(msg)
    cpmsg = ''
    msg.each_codepoint { |cp| cpmsg << format('%04x', cp) }
    cpmsg
  end
end

def main
  phone_number = ''
  ac = AtCommand.new

  ac.send("AT+CFUN=1\n")
  return unless ac.ok?

  ac.send("AT+CMGF=1\n")
  return unless ac.ok?

  ac.send("AT+CSMP=1,167,0,8\n")
  return unless ac.ok?

  ac.send("AT+CSCS=\"UCS2\"\n")
  return unless ac.ok?

  ac.send("AT+CMGS=\"#{phone_number}\"\n")
  return unless ac.prompt?

  msg = ac.pack('あ' * 63)
  ac.send(msg + 26.chr)
  return unless ac.sent?
end

main if $PROGRAM_NAME == __FILE__