Added a 'runtest' script that is responsible to check if Tcl is available and run the test. This is invoked from Makefile as well.

runtest

@@ -0,0 +1,9 @@
+#!/bin/bash
+TCL=tclsh8.5
+which $TCL
+if [ "$?" != "0" ]
+then
+    echo "You need '$TCL' in order to run the Redis test"
+    exit 1
+fi
+$TCL tests/test_helper.tcl $*

src/Makefile

@@ -207,7 +207,7 @@ dep:
 	$(CC) -MM *.c -I ../deps/hiredis -I ../deps/linenoise
 
 test: redis-server redis-check-aof
-	@(cd ..; (which tclsh8.5 >/dev/null && tclsh8.5 tests/test_helper.tcl --tags "${TAGS}") || echo "You need to install Tcl (tclsh8.5) in order to run tests.")
+	@(cd ..; ./runtest)
 
 bench:
 	./redis-benchmark