#!/usr/bin/perl

use strict;
use warnings;
use Text::Table;
use Data::Dumper;
use List::Util qw{max};
use Fcntl qw(:flock); # import LOCK_* and SEEK_END constants

$| = 1;

my $value = (); #create anonymous string_ref
my %hash = (); 

sub hash_sub {

    foreach my $arg (@_) {

	open (READ, "<" , $arg)
	    or die ("Could not open: ".$arg." - $!\n");
	
	flock(READ, LOCK_EX)
	    or die "Could not lock '".$arg."' - $!\n";

	if (-z "".$arg."") {
	    print "File '".$arg."' is empty!\n";
	    # -z  File has zero size (is empty).
	}

	my @doc_read = <READ>;

	chomp @doc_read;

	foreach $_ (@doc_read) {
	    my @result = split (':', $_);

	    if (/^\s*$/) { # /^\s*$/ check for "blank" lines may contain spaces or tabs
		next;
	    }

	    push (@$value , $result[3]);
	}
	$hash{$arg} = $value;
	$value = (); # emptying the string_ref for the next ARGV

	close (READ)
	    or die ("Could not close: ".$arg." - $!\n");
    }

    my $max_idx = max map $#$_, values %hash;

    my $tb = Text::Table->new;

    for my $i (0 .. $max_idx) {
	$tb->add( map $hash{$_}[$i], sort keys %hash);
    }
    return $tb;
}

my $h_table = hash_sub(@ARGV);
print $h_table;