#334 Speed-up rules with caching for_app decorator

thefuck/rules/grep_recursive.py

@@ -1,6 +1,9 @@
+from thefuck.utils import for_app
+
+
+@for_app('grep')
 def match(command, settings):
-    return (command.script.startswith('grep')
-            and 'is a directory' in command.stderr.lower())
+    return 'is a directory' in command.stderr.lower()
 
 
 def get_new_command(command, settings):