#!/usr/bin/perl
#
# $Id: plot.gif,v 1.14 2013/08/14 00:38:55 raeburn 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 '') {
$output = (split('\.',$0))[-1];
}
if ($output eq 'gif' || $output eq 'png') {
open(my $plot, "gnuplot $filename |");
print <<"END";
Content-type: image/$output
END
while (my $line = <$plot>) {
print($line);
}
} elsif ($output eq 'eps') {
print <<"END";
Content-type: text/html
eps plot creation
Creating eps plot
END
if (! system ("gnuplot $filename")) {
print "An error occurred.
\n".
"I am not going to tell you about it as I have not bothered ".
"to figure out how to get you the error text.\n";
} else {
print "EPS file generated successfully.
\n";
}
print "\n";
} else {
die "output $output is not a recognized value or has no value\n";
}
500 Internal Server Error
Internal Server Error
The server encountered an internal error or
misconfiguration and was unable to complete
your request.
Please contact the server administrator at
root@localhost to inform them of the time this error occurred,
and the actions you performed just before this error.
More information about this error may be available
in the server error log.