#!/usr/bin/perl
#
# $Id: plot.gif,v 1.9 2002/03/01 14:03:50 matthew 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/cgi-bin/plot.gif
#
# http://www.lon-capa.org/
#
use strict;

$|=1;

my $tmpdir = '/home/httpd/perl/tmp/';
my %data;
foreach (split/&/,$ENV{'QUERY_STRING'}) {
    my ($name,$value)=split/=/;
    $data{$name}=$value;
}
my $filename = $data{'file'};
# unescape filename
$filename =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;

die if ($filename =~ /\// || $filename !~ /_plot.data$/);
$filename = $tmpdir . $filename;
die "$data{'file'} does not exist\n" if (! -e $filename);

my $output = $data{'output'};
if ($output eq 'gif') {
    open PLOT, "gnuplot $filename |";
    print <<"END";
Content-type: image/gif

END
    while ($_=<PLOT>) {
	print;
    }
} elsif ($output eq 'eps') {
    system ("gnuplot $filename");
} else {
    die "output $output is not a recognized value or has no value\n";
}