#!/usr/bin/perl
#
# $Id: plot.gif,v 1.17 2020/02/19 18:53:17 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') {
if (open(my $plot, "export LANG='en_US.UTF-8'; gnuplot $filename |")) {
print <<"END";
Content-type: image/$output
END
while (my $line = <$plot>) {
print($line);
}
close($plot);
} else {
die "failed to open pipe to run gnuplot\n";
}
} elsif ($output eq 'eps') {
print <<"END";
Content-type: text/html
eps plot creation
Creating eps plot
END
if (! system ("export LANG='en_US.UTF-8'; 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";
}