--- loncom/cgi/plot.gif	2001/12/11 13:47:36	1.3
+++ loncom/cgi/plot.gif	2016/08/19 05:15:21	1.15
@@ -1,6 +1,6 @@
-#!/usr/bin/perl 
+#!/usr/bin/perl
 #
-# $Id: plot.gif,v 1.3 2001/12/11 13:47:36 matthew Exp $
+# $Id: plot.gif,v 1.15 2016/08/19 05:15:21 musolffc Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -24,212 +24,60 @@
 #
 # http://www.lon-capa.org/
 #
-###########################################################################
-#
-# CGI-BIN interface to GD, used for making mathematical plots.
-#
-# User specifies the following variables (given are defaults):
-#    height   = "100"
-#    width    = "100"
-#    xmin     = "-10.0"
-#    xmax     = " 10.0"
-#    ymin     = "-10.0"
-#    ymax     = " 10.0"
-#    transparent   (doesn't work with gif?)
-#    frame    
-#    drawaxes 
-#    drawtics 
-#    vtic_every = "1.0"
-#    htic_every = "1.0"
-#    xseries1  = "x1,x2,x3,x4,x5,...,xn"
-#    yseries1  = "y1,y2,y3,y4,y5,...,yn"
-#    xseries2  = ..
-#    yseries2  = ..
-#    ...
-#    label1 = "x,y,size,text"
-#    label2 = "x,y,size,text"
-#    label3 = "x,y,size,text"
-#    ...
-#
-#    size of a labelN is one of :
-#       giant, large, medium, small, tiny
-#
-###########################################################################
-use GD;
-
-my @inputs = split(/&/,$ENV{'QUERY_STRING'});
-foreach $input (@inputs) {
-    ($var,$val) = split /\=/,$input,2;
-    if (! defined($val)) {
-	$val = 1;
-    }
-    $In{lc($var)}=$val;
-}
-
-$height = &grab('height',100,\%In);
-$width  = &grab('width',100,\%In);
-$axis->{'xmin'} = &grab('xmin',-10,\%In);
-$axis->{'xmax'} = &grab('xmax', 10,\%In);
-$axis->{'ymin'} = &grab('ymin',-10,\%In);
-$axis->{'ymax'} = &grab('ymax', 10,\%In);
-$axis->{'xlen'} = $axis->{'xmax'} - $axis->{'xmin'};
-$axis->{'ylen'} = $axis->{'ymax'} - $axis->{'ymin'};
-$vtic_every = &grab('vtic_every',1.0,\%In);
-$htic_every = &grab('htic_every',1.0,\%In);
-
-my $image = new GD::Image($width,$height);
-
-# allocate standard colors
-my @BGvalues = split /,/,&grab('bgcolor','255,255,255',\%In);
-my @FGvalues = split /,/,&grab('fgcolor','0,0,0',\%In);
-my $bgcolor = $image->colorAllocate(@BGvalues);
-my $fgcolor = $image->colorAllocate(@FGvalues);       
-
-# Draw a fgcolor frame around the picture
-&drawtics($htic_every,$vtic_every) if (exists($In{'drawtics'}));
-&drawaxes($axis)                   if (exists($In{'drawaxis'}));
-&drawframe(1)                          if (exists($In{'frame'}));
-# make the background transparent if needed (this doesn't work, at least
-# not for gif images, don't know if it works for png)
-$image->transparent($bgcolor)       if (exists($In{'transparent'}));
-
-## Take care of labels and data series
-foreach (keys %In) {
-    if (/^label/) {
-	my ($x,$y,$size,$text) = split/,/,$In{$_};
-	&drawstring($text,$x,$y,$fgcolor,$size);
-	delete ($In{$_});
-	next;
-    } elsif (/^xseries/) {
-	$xname = $_;
-	$yname = $xname;
-	$yname =~ s/^x/y/;
-	(@X)=split/,/,$In{$xname};
-	(@Y)=split/,/,$In{$yname};
-	delete ($In{$xname});
-	delete ($In{$yname});	
-	if ($#X != $#Y) {
-	    &drawstring("size of $xname and $yname do not match",
-		       10,10,$fgcolor,"giant");
-	    next;
-	}
-	&drawcurve(\@X,\@Y);
-    }
-}
+use strict;
+use bytes;
 
+$|=1;
 
-# Tell the browser our mime-type
-print <<END;
-Content-type: image/gif
+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 |");
+    my $image_content= '';
+    while (my $line = <$plot>) {
+        $image_content .= $line;
+    }
+    my $length = bytes::length($image_content);
+    print <<"END";
+Content-type: image/$output
+Content-length: $length
 
+$image_content
 END
 
-my $BinaryData=$image->png;
-undef $image;
-binmode(STDOUT);
-open IMG,"|pngtopnm|ppmtogif 2>/dev/null"; # convert into a gif image
-print IMG $BinaryData; # output image
-$|=1;                  # be sure to flush before closing
-close IMG;
-
-
-#--------------------------------------------------------------------
-
-sub grab{
-    my ($name,$default,$h) = @_;
-    my $value = $h->{$name};
-    if (defined($value)) {
-	delete ($h->{$name}) ;
-    } else {
-	$value = $default;
-    }
-    return $value;
-}
-
-# transformPoint(x,y) where x,y are in the coordinates of axis will return
-# the coordinates transformed to the image coordinate system.
-sub transformPoint{
-    my ($x,$y) = @_;
-    my ($width,$height) = $image->getBounds();
-    $x = ( $x - $axis->{"xmin"}) * $width / ( $axis->{"xlen"});
-    $y = ( ( $axis->{"ylen"} ) - ($y - $axis->{"ymin"})) 
-	* $height / ( $axis->{"ylen"} );
-    return($x,$y);
-}
-
-sub drawaxes{
-    ($x1,$y1) = &transformPoint($axis->{"xmin"},0,$image,$axis);
-    ($x2,$y2) = &transformPoint($axis->{"xmax"},0,$image,$axis);
-    $image->line($x1,$y1,$x2,$y2,$fgcolor);
-    ($x1,$y1) = &transformPoint(0,$axis->{"ymin"},$image,$axis);
-    ($x2,$y2) = &transformPoint(0,$axis->{"ymax"},$image,$axis);
-    $image->line($x1,$y1,$x2,$y2,$fgcolor);
-}
+} elsif ($output eq 'eps') {
+    print <<"END";
+Content-type: text/html
+
+<html><head><title>eps plot creation</title></head>
+<body>
+<h2>Creating eps plot</h2>
 
-sub drawtics{
-    my ($htic_every,$vtic_every) = @_;
-    my ($width,$height) = $image->getBounds();
-    
-    $ticwidth  = ($width  > 99 ? 5 : int($width /20) + 1);
-    $ticheight = ($height > 99 ? 5 : int($height/20) + 1);
-
-    # Do tics along y-axis
-    for ($ntic = 0; $ntic <=int($axis->{"ylen"}/$vtic_every); $ntic++){
-	my ($x1,$y1) = &transformPoint(0,$axis->{"ymin"}+$ntic*$vtic_every);
-	my ($x2,$y2) = &transformPoint(0,$axis->{"ymin"}+$ntic*$vtic_every);
-	$x1 -= $ticwidth;
-	$x2 += $ticwidth;
-	$image->line($x1,$y1,$x2,$y2,$fgcolor);
-    }
-    # Do tics along x-axis
-    for ($ntic = 0; $ntic <=int($axis->{"xlen"}/$htic_every); $ntic++){
-	my ($x1,$y1) = &transformPoint( $axis->{"xmin"}+$ntic*$htic_every,0);
-	my ($x2,$y2) = &transformPoint( $axis->{"xmin"}+$ntic*$htic_every,0);
-	$y1 -= $ticheight;
-	$y2 += $ticheight;
-	$image->line($x1,$y1,$x2,$y2,$fgcolor);
-    }
-}
-
-sub drawcurve{
-    my ($X,$Y) = @_;
-    for($i=0;$i< (@$X-1);$i++) {
-	($x1,$y1) = &transformPoint($X->[$i  ],$Y->[$i  ]);
-	($x2,$y2) = &transformPoint($X->[$i+1],$Y->[$i+1]);
-	$image->line($x1,$y1,$x2,$y2,$fgcolor);
-    }
-}
-
-sub drawframe{
-    # Draw a frame around the picture.
-    my ($xoffset,$yoffset) = @_;
-    $xoffset = $xoffset || 1;
-    $yoffset = $yoffset || $xoffset;
-    my ($width,$height) = $image->getBounds();
-    $image->rectangle($xoffset-1,$yoffset-1,$width-$xoffset,$height-$yoffset,$fgcolor);
-}
-
-sub drawstring{
-    # Write some text on the image.
-    my ($text,$x,$y,$color,$fontName) = @_;
-    $font = gdGiantFont      if (lc($fontName) eq "giant" ||
-				 lc($fontName) eq "huge"     );
-    $font = gdLargeFont      if (lc($fontName) eq "large");
-    $font = gdMediumBoldFont if (lc($fontName) eq "medium");
-    $font = gdSmallFont      if (lc($fontName) eq "small");
-    $font = gdTinyFont       if (lc($fontName) eq "tiny");
-    if (! defined($font)) {
-	$font = gdGiantFont;
-	$text = "Font size error!";
+END
+    if (! system ("gnuplot $filename")) {
+        print "<h2>An error occurred.</h2>\n".
+            "I am not going to tell you about it as I have not bothered ".
+            "to figure out how to get you the error text.\n";
+    } else {
+        print "<h2>EPS file generated successfully.</h2>\n";
     }
-    ($x,$y) = &transformPoint($x,$y);
-    $image->string($font,$x,$y,$text,$color);
+    print "</body></html>\n";
+} else {
+    die "output $output is not a recognized value or has no value\n";
 }
-
-
-
-
-
-
-
-