rvm-prompt in rvm-0.0.62

- old
+ new

@@ -1,5 +1,8 @@
 #!/bin/bash
-if [ ! -z "$(which ruby | awk '/\.rvm/{print}')" ] ; then
-  echo "[$(which ruby | xargs dirname | xargs dirname | xargs basename | tr '-' ':')]"
+if [[ ! -z "$(which ruby | awk '/\.rvm/{print}')" ]] ; then
+  command=$(which ruby)
+  if [[ ! -z "$command" ]] ; then
+    echo "[$(echo $command | xargs dirname | xargs dirname | xargs basename | tr '-' ':')]"
+  fi ; unset command
 fi
 