#!/usr/bin/env perl
use strict;
use warnings;

my $state = 0; 

sub change_state {
        my $state = shift;
        return 1 if $state == 0;
        return 0 if $state == 1;
        die "epic fail"
}

sub read_between_hs {
        my $line=shift;
        if ($line =~ /^(j|E|G)/) {
                print $line;
        }
}

while (<DATA>) {
        my $line = $_;
        $state = change_state($state) if ($line =~ /^h/);
        read_between_hs($line) if ($state);
}

__DATA__
h start printing

x dontprintme
a dontprintme
G printme
j printme
E printme
h stop printing

j not between hs should not print
E dont print me
G dont print me

h start printing
definitely printable
j ahh back to not being ignored
G print
E print
e print -- just kidding
h stop printing