Shell Programming and Scripting

#!/usr/bin/perl
use strict;
use warnings;
use threads;
use Time::HiRes qw(usleep nanosleep);

my @downloadingFiles = ();
my $fileNumber = 0;
my $overallTimer = 0;
my $fileSize = 0;
my $temp1 = 0;
my $temp2 = 0;

#this is my timer which should run until 1000, but it actually stops when setupSenderAndReceiver function has terminated. It is monitoring the file size of the file which is being transferred through the socket.
sub GlobalTimer	{
	while($overallTimer <= 1000)	{
	$overallTimer++;
	sleep(1);
	$fileSize = -s "out$fileNumber";
	@downloadingFiles[$fileNumber] = $fileSize;
        $print "$overallTimer";
					}
		}

#this function uses two functions inside it to establish a server and client connection and send a file through a socket.
sub setupSenderAndReceiver{
$temp1 = $_[0];
$temp2 = $_[0];

#this script opens the server port
sub first {
system("/usr/bin/perl myPerlScript2.pl $temp1");
}

#this sends a command to a remote machine to start sending data.
sub second {
my @x = ("bash", "-c", "ssh ip_address_and_details_removed $temp2");
system(@x);
}

#this should instruction both processes to run at the same time and exit the thread upon completion.
my $firstThread = threads->create(\&first);
my $secondThread = threads->create(\&second);
firstThread->join();
secondThread->join();
}

#this is the thread I used to start the overall timer
my $globalT = threads->create(\&GlobalTimer);
$globalT->detach();
#this is the thread I used to create the file transfer
my $start = threads->create(\&setupSenderAndReceiver, $fileNumber);
$start->join();