Connect to GSM Modem - send raw AT commands

#!/usr/bin/perl
use Device::Modem;

my $modem = new Device::Modem( port => '/dev/modem');
if($modem->connect(baudrate => 9600)) {
  print "connected \n";
} else {
  print "connect to modem is failed $! \n";
}

$modem->atsend('AT+CMGL="STO UNSENT"' . Device::Modem::CR);
print $modem->answer();

I just connect to modem and send AT+CMGL (Read SMS message, in this case STO UNSENT [message in unsent folder])