#!/usr/bin/perl
# ping cgi-script
# $Id: ping.pl,v 1.5 2003/09/01 03:37:27 albertel Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#


$|=1;

use lib '/home/httpd/lib/perl/';
use LONCAPA::Configuration;

use IO::File;
use IO::Socket;

my %perlvar;

# -------------------------------------------------- Non-critical communication
sub reply {
    my ($cmd,$server)=@_;
    my $peerfile="$perlvar{'lonSockDir'}/$server";
    my $client=IO::Socket::UNIX->new(Peer    =>"$peerfile",
                                     Type    => SOCK_STREAM,
                                     Timeout => 10)
       or return "con_lost";
    print $client "$cmd\n";
    my $answer=<$client>;
    chomp($answer);
    if (!$answer) { $answer="con_lost"; }
    return $answer;
}


# --------------------- Read loncapa.conf (and by default loncapa_apache.conf).
my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
%perlvar=%{$perlvarref};
undef $perlvarref; # remove since sensitive and not needed
delete $perlvar{'lonReceipt'}; # remove since sensitive and not needed
delete $perlvar{'lonSqlAccess'}; # remove since sensitive and not needed

$testhost=$ENV{'QUERY_STRING'};
$testhost=~s/\W//g;

print "Content-type: text/plain\n\n".
      &reply('ping',$testhost)."\n";