Index: trunk/ippScripts/scripts/chip_imfile.pl
===================================================================
--- trunk/ippScripts/scripts/chip_imfile.pl	(revision 31939)
+++ trunk/ippScripts/scripts/chip_imfile.pl	(revision 31941)
@@ -44,4 +44,7 @@
 my ( $exp_id, $chip_id, $class_id, $chip_imfile_id, $uri, $camera, $outroot, $dbname, $run_state, $reduction, $threads, $verbose,
      $no_update, $save_temps, $no_op, $redirect, $magicked, $deburned );
+
+my $zaplog = 0;
+
 GetOptions(
     'exp_id=s'          => \$exp_id,    # Exposure identifier
@@ -62,4 +65,5 @@
     'no-op'             => \$no_op,     # Don't do any operations?
     'redirect-output'   => \$redirect,
+    'zaplog'            => \$zaplog,
     'save-temps'        => \$save_temps, # Save temporary files?
     ) or pod2usage( 2 );
@@ -90,5 +94,5 @@
 my ($logDest, $traceDest);
 if ($run_state eq 'new') {
-    $logDest = prepare_output("LOG.IMFILE", $outroot, $class_id, 0);
+    $logDest = prepare_output("LOG.IMFILE", $outroot, $class_id, $zaplog);
     $traceDest = prepare_output("TRACE.IMFILE",  $outroot, $class_id, 1);
 } else {
Index: trunk/ippScripts/scripts/diff_skycell.pl
===================================================================
--- trunk/ippScripts/scripts/diff_skycell.pl	(revision 31939)
+++ trunk/ippScripts/scripts/diff_skycell.pl	(revision 31941)
@@ -40,4 +40,6 @@
 my ($skycell_id, $diff_skyfile_id);
 my ($use_convolved);
+my $zaplog = 0;
+
 GetOptions(
     'diff_id=s'         => \$diff_id, # Diff identifier
@@ -55,4 +57,5 @@
     'no-op'             => \$no_op, # Don't do any operations?
     'redirect-output'   => \$redirect,
+    'zaplog'            => \$zaplog, # delete any previous log file
 ) or pod2usage( 2 );
 
@@ -82,4 +85,6 @@
     $logDest .= '.update';
     # ... well we can just do the dirty work here
+    $ipprc->kill_file($logDest);
+} elsif ($zaplog) {
     $ipprc->kill_file($logDest);
 }
Index: trunk/ippScripts/scripts/warp_skycell.pl
===================================================================
--- trunk/ippScripts/scripts/warp_skycell.pl	(revision 31939)
+++ trunk/ippScripts/scripts/warp_skycell.pl	(revision 31941)
@@ -38,4 +38,6 @@
 
 my ($warp_id, $skycell_id, $warp_skyfile_id, $tess_dir, $reduction, $camera, $dbname, $outroot, $threads, $run_state, $magicked, $verbose, $no_update, $no_op, $redirect, $save_temps);
+my $zaplog = 0;
+
 GetOptions(
     'warp_id|i=s'         => \$warp_id, # Warp identifier
@@ -53,4 +55,5 @@
     'no-update'           => \$no_update, # Don't update the database?
     'no-op'               => \$no_op, # Don't do any operations?
+    'zaplog'              => \$zaplog, # delete previous logfile
     'redirect-output'     => \$redirect,
     'save-temps'          => \$save_temps, # Save temporary files?
@@ -74,5 +77,5 @@
 my $do_stats;
 if ($run_state eq 'new') {
-    $logDest = prepare_output("LOG.EXP", $outroot, $skycell_id, 0);
+    $logDest = prepare_output("LOG.EXP", $outroot, $skycell_id, $zaplog);
     $traceDest = prepare_output("TRACE.EXP", $outroot, $skycell_id, 1);
     $do_stats = 1;