#!/usr/bin/perl -wl
# gate : a printer gate
use strict;
use Getopt::Std;
use constant OPEN => 1;
use constant SHUT => 0;

use vars qw($opt_p $opt_o $opt_s $opt_b $opt_l);
local ($opt_p, $opt_o, $opt_s, $opt_b, $opt_l);
getopts(qw(pb:o:s:l:));

unless ($opt_o or $opt_b ){
	usage() unless $opt_p;
}

if (@ARGV){
 open FH, $ARGV[0] or die $!; 
} else { 
 *FH = \*DATA ;
}
my $enter    = $opt_p ? $opt_p : SHUT; # breeze
my $breach   = $opt_b ? $opt_b : 'the burgler breaks in';
my $open     = $opt_o ? $opt_o : 'the butler opens the door';
my $shut     = $opt_s ? $opt_s : 'the bouncer shuts the door';
my $last     = $opt_l ? $opt_l : 'the bellhop is last through the door';

while (my $door = $_ = <FH>){
	chomp ($door,$_);
	exit   if $door =~ /^$shut$/;           # bouncer
	$enter = OPEN  if $door =~ /^$breach$/; # burgler
	$enter and print;
	$enter = OPEN  if $door =~ /^$open$/;   # butler
	exit   if $door =~ /^$last$/;           # bellhop
}

sub usage
{
	print "The door is shut\n",
"$0
    -p (p_neuma is Greek for 'breeze')
    -b (burgler b_reaks in)               <item>
    -o (butler o_pens the door)           <item>
    -s (bouncer s_huts the door)          <item>
    -l (bellhop is l_ast through the door)<item>
";
	die"\n";
}

__END__
apple
banana
pear
peach
grape
orange