Getting unique ID of a user's machine

Hello,
Many thanks all for the help
Here is Dan revisited code and checks. Need some improvements like checking Windows and Ruby version.
@DanRathbun
String.encode needed? Why?
How do you colorize your code on the forum?

so code picture


and code (thanks to Dan. I’ve got colorized code!)

def system_read(str_cmd)
      begin
        filename = nil
        raise('system_read(str_cmd). str_cmd must be a string.') unless str_cmd.is_a?(String)
        raise('system_read(str_cmd). str_cmd must not be empty string.') if str_cmd.length == 0
        str_data = IO::popen(str_cmd) {|io| io.read}.strip()
        bol_exit = ($?.exitstatus == 0)
        if str_data.empty? or !bol_exit
          filename = ENV['TMP'].encode('UTF-8').gsub('\\','/') + "/" + (Time.new.to_f * 1000).to_i.to_s
          bol_exit = system(str_cmd + " > " + filename)
          str_data = File.read(filename).strip()
        end
      return bol_exit, str_data
      rescue => e
        puts e.message
      ensure
        if filename && File::exist?(filename)
          File::delete(filename) rescue nil
        end
      end
    end

    bol_exit, str_data = system_read('echo "Hello world!"')
    puts "    with Sketchup " + Sketchup.version.split(".")[0]+"\n      "+
	bol_exit.to_s + ", ->" + str_data + "<-\n    end with"

now checks
PCintelWin7updatedWin10

    with Sketchup 17
      true, ->"Hello world!"<-
    end with
    with Sketchup 16
      true, ->"Hello world!"<-
    end with
    with Sketchup 15
      true, ->"Hello world!"<-
    end with
    with Sketchup 14
      true, ->"Hello world!"<-
    end with
    with Sketchup 13
      true, ->"Hello world!"<-
    end with
    with Sketchup 8
      true, ->"Hello world!"<-
    end with

PCamdWin10

    with Sketchup 17
      true, ->"Hello world!"<-
    end with
    with Sketchup 8
      true, ->"Hello world!"<-
    end with

PCintelWin7

    with Sketchup 16
      true, ->"Hello world!"<-
    end with
    with Sketchup 8
      true, ->"Hello world!"<-
    end with

all right. good news!

@john_drivenupthewall
may you run the script on your Macs and tell me results please?
@MSP_Greg or any other Windows User facing same issue
may you run the script and tell me results please?

Have a good day
WhyDi