#!/bin/perl
use Device::SerialPort;
use Getopt::Long;
my $port = Device::SerialPort->new("/dev/ttyUSB0");
my $char = "";
my $data = "";
my $warning = "";
my $critical = "";
my $help = "";
my $fahrenheit = "";
my $celsius = "";

GetOptions ('h' => \$help, 'm' => \$celsius, 'f' => \$fahrenheit ,'w=s' => \$warning, 'c=s' => \$critical);

if ( $help ) {
      print "Temperature checker for sensor by Todd\n";
      print "--------------------------------------\n";
      print "-h this help listing\n";
      print "-m get temperature in Celsius\n";
      print "-f get temperature in Fahrenheit\n";
      print "-w # Warning if above this temperature\n";
      print "-c # critical if above this temperature\n";
      exit 0;
    }

$port->baudrate(9600); # you may change this value
$port->databits(8); # but not this and the two following
$port->parity("none");
$port->stopbits(1);

my $tEnd = time()+2; # 2 seconds in future
while (time()< $tEnd) { # end latest after 2 seconds
  my $c = $port->lookfor(); # char or nothing
  next if $c eq ""; # restart if noting
  last;
}

while (1) { # and all the rest of the gremlins as they come in one piece
  my $c = $port->lookfor(); # get the next one
  last if $c eq ""; # or we're done
}
while (1) {
    $char = $port->lookfor();
    if ($char == "Temperature Sensor Ready") {
     if ( $celsius ) {
	$port->write("C\r\n");
     }else{
       	$port->write("F\r\n");
     }
    }else{
       $data = $char;
       last;
    }
}

chop($data);

if ($data > $critical ) {
  print "CRITICAL: Temperature is $data | Temperature=$data;$warning;$crtical;0;100\n";
  exit 2;
  }
if ( $data > $warning ) {
  print "WARNING: Temperature is $data | Temperature=$data;$warning;$crtical;0;100\n";
  exit 1;
  }
if ( $data < $warning ) {
  print "OK: Temperature is $data | Temperature=$data;$warning;$critical;0;100\n";
  exit 0;
  }
print "The Temp s $char\n";
print "Warning is set to $warning\n";
print "Critical is set to $critical\n";
exit 2;