fixed bash prompt hack: now it ignores rc (thanks, straintcmp)

demo.sh

@@ -45,10 +45,10 @@ function wait()
 function prompt()
 {
     invalidcmd="somethingthatshouldbetotallynotacommandinanygivenenvironment"
-    expPS1=$(echo $invalidcmd |
-             bash -i 2>&1     |
-             grep $invalidcmd |
-             head -n 1        |
+    expPS1=$(echo $invalidcmd    |
+             bash --norc -i 2>&1 |
+             grep $invalidcmd    |
+             head -n 1           |
              sed "s/$invalidcmd//g")
     printf "$expPS1"
 }