--- DirectedGraphPlugin.pm.orig	2005-04-26 14:59:31.000000000 +0200
+++ DirectedGraphPlugin.pm	2005-04-26 14:51:25.000000000 +0200
@@ -43,10 +43,9 @@
 
 my $HASH_CODE_LENGTH=32;
 my %hashed_math_strings=();
-#my $cmd = '/home/mrjc/packages/graphviz/bin/dot';
-my $cmd = '/usr/bin/dot';
+my $cmd = '/usr/bin/dot -T%FORMAT|S% %INFILE|F% -o %OUTFILE|F%';
 my $tmpFile = '/tmp/'.$pluginName."$$";
-
+	
 # =========================
 sub initPlugin
 {
@@ -110,15 +109,14 @@
     }
     # create the png
     else {
-        $command=system($cmd." -Tpng $tmpFile -o $image");
-        # If you've installed the netpbm package, you could alternatively 
-        # use this command to smooth-scale the image
-        #$command=system($cmd." -Tpng $tmpFile | pngtopnm | pnmscale 0.7 | pnmtopng > $image");
-        if($command) {
+        my ($output, $status) = &TWiki::readFromProcess($cmd,
+	  FORMAT => 'png', INFILE => $tmpFile, OUTFILE => $image);
+        
+        if($status) {
             # errors existed so remove created files
             unlink "$image";
             unlink $tmpFile;
-            return "<nop>DirectedGraph Error: syntax error - $command";
+	    return &showError($status, $output, $hashed_math_strings{"$hash_code"});
         }
     }
 
@@ -132,12 +130,13 @@
         }
         # create the map
         else {
-            $command=system("$cmd -Tcmapx -o $cmapx $tmpFile");
-            if($command) {
+	    my ($output, $status) = &TWiki::readFromProcess($cmd,
+	      FORMAT => 'cmapx', INFILE => $tmpFile, OUTFILE => $cmapx);
+            if($status) {
                 # errors existed so remove created files
                 unlink "$cmapx";
                 unlink $tmpFile;
-                return "<noc>DirectedGraph Error: syntax error";
+		return &showError($status, $output, $hashed_math_strings{"$hash_code"});
             }
         }
     }
@@ -159,4 +158,14 @@
     }
 }
 
+# =========================
+sub showError {
+  my ($status, $output, $text) = @_;
+
+  $output =~ s/^.*: (.*)/$1/;
+  my $line = 1;
+  $text =~ s/\n/sprintf("\n%02d: ", $line++)/ges;
+  $output .= "<pre>$text\n</pre>";
+  return "<font color=\"red\"><nop>DirectedGraph Error ($status): $output</font>";
+}
 1;