--- hddtemp_smartctl.orig	2009-04-07 21:40:17.000000000 +0900
+++ hddtemp_smartctl	2009-04-07 21:47:37.000000000 +0900
@@ -80,6 +80,12 @@
 
 use strict;
 
+sub internal_name {
+    my $dev = shift;
+    $dev =~ s|[-/.]|_|g;
+    return $dev;
+}
+
 my $smartctl = exists $ENV{smartctl} ? $ENV{smartctl} : undef;
 
 # If the envvar is not set, look for smartctl
@@ -138,7 +144,7 @@
     print "graph_vlabel temp in °C\n";
     print "graph_category sensors\n";
     print "graph_info This graph shows the temperature in degrees Celsius of the hard drives in the machine.\n";
-    print "$_.label $_\n" foreach @drives;
+    print internal_name($_) .".label $_\n" foreach @drives;
     exit 0;
   }
 }
@@ -156,10 +162,11 @@
   }
 
   my $output = `$cmd`;
+  my $name = internal_name($_);
   if ($output =~ /Current Drive Temperature:\s*(\d+)/) {
-    print "$_.value $1\n";
+    print "$name.value $1\n";
   } elsif ($output =~ /^(194 Temperature_Celsius.*)/m) {
     my @F = split ' ', $1;
-    print "$_.value $F[9]\n";
+    print "$name.value $F[9]\n";
   }
 }