#!/usr/bin/perl -Tw
use strict;

use Term::ReadKey;

# Directory to check
my $data_dir='/path/to/directory';
# Seconds between directory checks
my $poll_wait='5';

TEST:{
	# Process any incoming files
	if (check_directory()){
		process_files();
		redo TEST;
	}
	else{
	# Otherwise check for any key press while waiting
		my $counter=0;
		ReadMode('cbreak');
		CHECK:{
			my ($char);
			# Check if the user pressed a key
			if (defined ($char = ReadKey(-1))){
				ReadMode('normal');
				exit();
			}
			# Is it time to check the incoming directory?
			elsif($counter >= $poll_wait){
				$counter=0;
				ReadMode('normal');
				redo TEST;
			}
			# Sleep a bit before checking the kyb again.
			else{
				sleep(1);
				$counter++;
				redo CHECK;
			}
		}
	}
}
# We should never get here, but this restarts the loop if we do
redo TEST;

sub check_directory{
    print "\nChecking directory...\n";
    opendir DIR, "$data_dir" or die "Problems opening $data_dir: $!";
    while ( my $dir = readdir DIR ) {
        next if ( $dir =~ m/^\.\.?$/ );
        closedir DIR;
        return 1;
    }
    closedir DIR;
    print "Directory Empty\nPress A Key to Stop\n";
    return 0;
}

sub process_files{
	# do somthing like...
	print "The directory has something!\n";
	exit();
}