Ping a host and announce its status; requires macOS or suitable replacement for the say command line app.

pingr

#!/usr/bin/env ruby

require 'logger'
require 'open3'
require 'optparse'
require 'ostruct'
require 'thread'

class ShellScript

  ::Version = [0,0,1]

  attr_accessor :options

  def initialize(args)
    @options = OpenStruct.new
    @options.count = nil
    @options.log = '/dev/null' # Send logging data to /dev/null by default.
    @options.log_level = Logger::INFO
    @options.debug = false
    @options.terse = false

    opt_parser = OptionParser.new do |opt|
      opt.banner = <<HEREDOC
NAME
    pingr - ping reporter audibly reports the status of a host

SYNOPSIS
    #{File.basename($0)} [OPTION]... [HOST]...

HEREDOC

      opt.on("-cCOUNT","--count=COUNT","Limit ping check to COUNT pings.") do |count|
        @options.count = count
      end

      opt.on("-d","--debug","Log debug messages.") do
        @options.log_level = Logger::DEBUG
      end

      opt.on("-IINTERFACE","--iface=INTERFACE","Bind ping to INTERFACE for sending.") do |interface|
        @options.interface = interface
      end

      opt.on("-lOUTFILE","--log=OUTFILE","Log debugging information to a filename, STDOUT, or STDERR.") do |filename|
        case filename
        when 'STDOUT'
          @options.log = $stdout
        when 'STDERR'
          @options.log = $stederr
        else
          @options.log = filename
        end
      end

      opt.on("-t","--terse","Terse output; don't bother saying the hostname.") do
        @options.terse = true
      end

      # Default options (these aren't specific to this app).

      opt.on_tail("-h","--help","Print usage information.") do
        $stderr.puts opt_parser
        exit 0
      end

      opt.on_tail("--version", "Show version and exit.") do
        puts ::Version.join('.')
        exit 0
      end
    end

    begin 
      opt_parser.parse!
    rescue OptionParser::InvalidOption => e
      $stderr.puts "Specified #{e}"
      $stderr.puts opt_parser
      exit 64 # EX_USAGE
    end

    if ARGV.size < 1
      $stderr.puts "No IP address provided."
      $stderr.puts opt_parser
      exit 64 # EX_USAGE
    end

    unless say?
      $stderr.puts red("The say command is not available on this system.")
      exit 78 #EX_CONFIG
    end

    @host = ARGV.pop

    @host_say = @options.terse ? nil : @host
    @host_status = nil
    @say_queue = Queue.new

    setup_logger
  end

  def run!
    announce
    ping
  end

  # Update host status; called for every line of output (STDERR and STDOUT) from the ping command.
  def update_status(line)
    previous_status = @host_status
    current_status = parse_line(line)

    return nil if current_status == :ignore

    @host_status = current_status

    if @host_status != previous_status
      case @host_status
      when :up
        add_announcement "Host #{@host_say} is up."
      when :down
        add_announcement "Host #{@host_say} is down."
      else
        add_announcement "Unknown status encountered."
      end
    end
  end

  # Add an announcement to the queue.
  def add_announcement(line)
    @say_queue.clear
    @say_queue << line
  end

  # Parse the output of ping and return a host status.
  def parse_line(line)
    status = :ignore
    case line
    when /^PING/
      status = :ignore
    when /localhost/ # If you've reached localhost, you've screwed something up, or you're testing.
      status = :ignore
    when /timeout/i # Host is down if 'timeout' is found in line.
      status = :down
    when /unreachable/i # Host is down if network is unreachable.
      status = :down
    when /no route to host/i # Host is down if no route exists.
      status = :down
    when /time to live exceeded/i # Host is down if TTL is exceeded.
      status = :down
    when /ttl expired/i # Host is down if TTL is exceeded (Linux version).
      status = :down
    when /bytes from/i # Host is up if 'bytes from' is found in line.
      status = :up
    end

    @logger.debug "Status: #{status.to_s.rjust(6)} Line: '#{line}'"

    return status
  end

  # Ping the host.
  def ping
    cmd = []
    cmd << "ping"
    cmd << "-c #{@options.count}" if @options.count 
    cmd << "#{flag_for_iface} #{options.interface}" if @options.interface
    cmd << @host
    cmd = cmd.join(' ')
    puts "Executing: #{blue(cmd)}"

    # Use Open3#popen2e so we get both stdout and stderr content in one stream.
    Open3.popen2e(cmd) do |stdin, stdout_and_stderr, thread|
      while line = stdout_and_stderr.gets do
        $stderr.puts line
        update_status line.chomp
      end
    end
  end

  # Spawns an announcer thread that looks for enqueued messages and speaks them aloud.
  def announce
    Thread.new do
      loop do
        say @say_queue.pop
      end
    end
  end

  # Say a message aloud.
  def say(msg)
    `say #{msg}`
  end

  # Check to make sure the say command is available on the system.
  def say?
    system('which say > /dev/null 2>&1')
  end

  # Return or setup logger
  def setup_logger
    @logger ||= Logger.new(@options.log)
    @logger.level = @options.log_level
  end

  def flag_for_iface
    case platform
    when :linux
      "-I"
    when :osx
      "-b"
    else
      "-I"
    end
  end

  def platform
    case `uname -a`
    when /Linux/i
      return :linux
    when /Darwin/i
      return :osx
    else
      return :unkown
    end
  end

  ## Embedded library methods; because, scripting!
  def colorize(text, color_code)
    "\e[#{color_code}m#{text}\e[0m"
  end
  def red(text); colorize(text, 31); end
  def green(text); colorize(text, 32); end
  def blue(text); colorize(text, 34); end
end

begin
  if $0 == __FILE__
    ShellScript.new(ARGV).run!
  end
rescue Interrupt
  # Ctrl^C
  Thread.list.each do |thread|
    thread.exit unless thread == Thread.current
  end
  exit 130
rescue Errno::EPIPE
  # STDOUT was closed
  exit 74 # EX_IOERR
end