Index: openacs-4/packages/xotcl-request-monitor/tcl/throttle_mod-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-request-monitor/tcl/throttle_mod-procs.tcl,v
diff -u -r1.19 -r1.20
--- openacs-4/packages/xotcl-request-monitor/tcl/throttle_mod-procs.tcl	8 Dec 2008 18:48:36 -0000	1.19
+++ openacs-4/packages/xotcl-request-monitor/tcl/throttle_mod-procs.tcl	26 Dec 2008 01:09:51 -0000	1.20
@@ -829,16 +829,16 @@
   }
   loadAvg updateValue
 
-
-  if {[file readable ${logdir}/counter.log]} {
+  set tail [::util::which tail]
+  if {[file readable ${logdir}/counter.log] && $tail ne ""} {
     #
     # Populate the counters from log file
     #
     ns_log notice "+++ request-monitor: initialize counters"
     
     # Create the file to load. This is per hour = 60*3 + 2 lines
     set number_of_lines [expr {182 * [trend-elements]}]
-    exec /usr/bin/tail -n $number_of_lines ${logdir}/counter.log >${logdir}/counter-new.log
+    exec $tail -n $number_of_lines ${logdir}/counter.log >${logdir}/counter-new.log
     
     set f [open $logdir/counter-new.log]
     while {-1 != [gets $f line]} {