fix zstdcat
diff --git a/tests/playTests.sh b/tests/playTests.sh
index c539d56..dfca1de 100755
--- a/tests/playTests.sh
+++ b/tests/playTests.sh
@@ -100,8 +100,10 @@
 
 
 $ECHO "\n**** Pass-Through mode **** "
-$ECHO "Hello world !" | $ZSTD -df
-$ECHO "Hello world !" | $ZSTD -dcf
+$ECHO "Hello world 1!" | $ZSTD -df
+$ECHO "Hello world 2!" | $ZSTD -dcf
+$ECHO "Hello world 3!" > tmp1
+$ZSTD -dcf tmp1
 
 
 $ECHO "\n**** frame concatenation **** "