#!/usr/bin/perl
use strict;
use Pod::Usage;
use Getopt::Std;

my @tmp;
my $tmp;
our $PORT;
our $BAUD;
our $PARITY;
our $DATA;
our $STOP;
our $ERR;
our $ERR1;
our $ERR2;
our $ob;

sub FindCOM{
    
    # modern laptops don't have a RS232 port so a RS232 adapter must be used
    # DOS command "mode" finds the number of COM when the RS232 is connected

    open(LISTDIR,"mode |") || die;
    @tmp=<LISTDIR>;
    close(LISTDIR);
      
    # detecting the COM port

    if($tmp[1]=~/COM/){
        
        # variables $ERR, $ERR1 and $ERR2 are temporary
        
        $ERR="n";
        $ERR1="Type a string in the edit line (below) and press <Enter>.";
        $ERR2="(or wait for the remote device to send data).";
       
        $PORT=$tmp[1];
        chomp($PORT);
        $PORT=~s/Status for device //i;
        $PORT=~s/://;
        
        # setting the COM port
        # - variable $PORT
        # - 19200: baud rate
        # - n: none parity
        # - 8: data bits
        # - 1: stop bits
        
        open(LISTDIR,"mode $PORT 19200,n,8,1 |") || die;
        @tmp=<LISTDIR>;
        close(LISTDIR);
        
        $BAUD=$tmp[3];
        chomp($BAUD);
        $BAUD=~s/ //g;
        $BAUD=~s/Baud://i;
        
        $PARITY=$tmp[4];
        chomp($PARITY);
        $PARITY=~s/ //g;
        $PARITY=~s/Parity://i;
        
        $DATA=$tmp[5];
        chomp($DATA);
        $DATA=~s/ //g;
        $DATA=~s/databits://i;
        
        $STOP=$tmp[6];
        chomp($STOP);
        $STOP=~s/ //g;
        $STOP=~s/stopbits://i;
        
        # opening the COM port
        # in the version without Tk the opened COM port from here worked

        $ob = Win32::SerialPort->new ($PORT) || die "\tSERIAL PORT ERROR: $PORT IS BUSY OR NOT AVAILABLE\n\n"; 

    }
    else{
        $ERR="y";
        $ERR1="Failed to initialize the port.";
        $ERR2="Did you forget to connect RS232 adapter to USB?";
    }
}
1;