#!/usr/bin/perl
use warnings;
use strict;
use Term::ReadKey;

my $char='q';
my @array = ('aa' .. 'zz');
my $print_go = 1;
my $ch;

while(1){

ReadMode ('cbreak');

if (defined ( $ch = ReadKey(-1))){ 
    #input was waiting and it was $ch
     print "$ch\n"; 
     if ($ch eq $char){exit(0)};
     if ($ch eq ' '){ $print_go = 0 }; #space stops print
     if ($ch eq 'g'){ $print_go = 1 };
     if ($ch eq 'x'){ exit };
   print "$ch\n";
   
 }else{
    # no input was waiting
    #your program goes here
 #   print "############################\n";
    
    my $val = shift @array;
    
    if( $print_go ) { print "$val\n" }
    
    select(undef,undef,undef,.1);

}

ReadMode ('normal'); # restore normal tty settings
}