--- loncom/cgi/plot.gif	2016/08/19 05:15:21	1.15
+++ loncom/cgi/plot.gif	2020/02/19 18:53:17	1.17
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# $Id: plot.gif,v 1.15 2016/08/19 05:15:21 musolffc Exp $
+# $Id: plot.gif,v 1.17 2020/02/19 18:53:17 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -25,7 +25,6 @@
 # http://www.lon-capa.org/
 #
 use strict;
-use bytes;
 
 $|=1;
 
@@ -48,18 +47,19 @@ if ($output eq '') {
 }
 
 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";
+    if (open(my $plot, "export LANG='en_US.UTF-8'; gnuplot $filename |")) {
+
+        print <<"END";
 Content-type: image/$output
-Content-length: $length
 
-$image_content
 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";
@@ -70,7 +70,7 @@ Content-type: text/html
 <h2>Creating eps plot</h2>
 
 END
-    if (! system ("gnuplot $filename")) {
+    if (! system ("export LANG='en_US.UTF-8'; 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";