diff -up collectl-3.5.1/readS.orig collectl-3.5.1/readS
--- collectl-3.5.1/readS.orig	2011-08-02 10:51:09.000000000 +0200
+++ collectl-3.5.1/readS	2011-08-02 10:56:35.000000000 +0200
@@ -5,7 +5,7 @@
 # readS may be copied only under the terms of either the Artistic License
 # or the GNU General Public License, which may be found in the source kit
 
-use Switch;
+use feature qw(switch);
 use Getopt::Std;
 
 my $Version=  '1.0';
@@ -75,13 +75,13 @@ while ($catvar ne '+')
   print "  Oper: $oper  Expr: $expr  Leftover: $catvar\n"    if $debug;
 
   # take appropriate action, aborting when unkown operator
-  switch ($oper)
+  given ($oper)
   {
-    case '+' { $result+=$value; }
-    case '-' { $result-=$value; }
-    case 'X' { $result*=$value; }
-    case '/' { $result/=$value; }
-    else { error("Unkown operator '$oper', aborting..."); }
+    when ('+') { $result+=$value; }
+    when ('-') { $result-=$value; }
+    when ('X') { $result*=$value; }
+    when ('/') { $result/=$value; }
+    default { error("Unkown operator '$oper', aborting..."); }
   }
   print "  Value: $value  Subtotal: $result\n"    if $debug;
 }