#!/usr/bin/perl #-w

#use warnings;
#use strict;

my @keys = keys %ENV;
my @values = values %ENV;

my $counter=0;
foreach (@keys)
{
	$counter++;
	print "($counter) $_ ";
	next unless ($_);
}

print "\n\nEnter \"all\" to display all enviroment variables. Enter name or number of variable to display single variable.\n";
my $input = (<STDIN>); # () case insensitive 
$input =~ s/\s//gi; # g global, \s whitespace

if ($input =~ /(all)/i) # i case insensitive
{	
	my $count = @keys;
	print STDOUT "$count variables to display:\n";

	my $counter;
	my $i=-1;
	foreach (@keys) 
	{
	  	$i++;
		$counter = $i+1;

		unless ($values[$i]) { $values[$i] = "Empty value."; }
	
		if ($keys[$i]) 
		{
			print STDOUT "\n$counter $keys[$i]:\n$values[$i]\n";
			if ($counter == $count) 
			{
				print STDOUT "\nAll enviroment variables displayed. :)\n";		
			}
		}
		sleep(1);	
	}
}
else
{	
	if ($input =~ /[0-9]/)
	{
		$input = $input-1;
		print "$values[$input]\n";
	}
	else
	{
		$input = uc $input;
		if ($ENV{"$input"})
		{
			print $ENV{"$input"};
		}
		else
		{
			print "Empty value.\n";
		}
	}
}