tracer scripts: silence error message in case PID directory is empty

If the directory has not yet been populated by any of the tracers, the
user doesn't need to know about it.

2 files changed, 4 insertions, 4 deletions

diff --git a/ft-trace-overheads b/ft-trace-overheads
index c1f597d..79453a5 100755
--- a/ft-trace-overheads
+++ b/ft-trace-overheads
@@ -116,11 +116,11 @@ do
         COUNT=$((COUNT + 1))
 done
 
-READY=`ls $DIR/*.pid | wc -l`
+READY=`ls $DIR/*.pid 2>/dev/null | wc -l`
 while [[ $READY != $COUNT ]]
 do
     sleep 0.5
-    READY=`ls $DIR/*.pid | wc -l`
+    READY=`ls $DIR/*.pid 2>/dev/null | wc -l`
 done
 
 rm $DIR/*.pid
diff --git a/st-trace-schedule b/st-trace-schedule
index 3bcd511..52f9400 100755
--- a/st-trace-schedule
+++ b/st-trace-schedule
@@ -92,11 +92,11 @@ do
     COUNT=$((COUNT + 1))
 done
 
-READY=`ls $DIR/*.pid | wc -l`
+READY=`ls $DIR/*.pid 2>/dev/null | wc -l`
 while [[ $READY != $COUNT ]]
 do
     sleep 0.5
-    READY=`ls $DIR/*.pid | wc -l`
+    READY=`ls $DIR/*.pid 2>/dev/null | wc -l`
 done
 
 rm $DIR/*.pid