Generalize test

extra/io/unix/pipes/pipes-tests.factor

@@ -2,7 +2,7 @@ USING: tools.test io.pipes io.unix.pipes io.encodings.utf8
 io.encodings io namespaces sequences ;
 IN: io.unix.pipes.tests
 
-[ { 0 0 } ] [ { "ls" "grep x" } run-pipeline ] unit-test
+[ { 0 0 } ] [ { "ls" "grep ." } run-pipeline ] unit-test
 
 [ { 0 f 0 } ] [
     {
@@ -12,6 +12,6 @@ IN: io.unix.pipes.tests
             output-stream [ utf8 <encoder> ] change
             input-stream get lines reverse [ print ] each f
         ]
-        "grep x"
+        "grep ."
     } run-pipeline
 ] unit-test