1 files changed, 10 insertions, 6 deletions

diff --git a/src/Trivmix.hs b/src/Trivmix.hs
index 2d6a50a..a754e76 100644
--- a/src/Trivmix.hs
+++ b/src/Trivmix.hs
@@ -37,12 +37,16 @@ data Options = Options
 
 optionParser :: Parser Options
 optionParser = Options <$>
-               strOption ( long "input"
-                           <> metavar "STRING"
-                         )
-               <*> strOption ( long "output"
-                               <> metavar "STRING"
-                             )
+               (fromMaybe "in" <$> optional (strOption ( long "input"
+                                                         <> metavar "STRING"
+                                                       )
+                                            )
+               )
+               <*> (fromMaybe "out" <$> optional (strOption ( long "output"
+                                                              <> metavar "STRING"
+                                                            )
+                                                 )
+                   )
                <*> strOption ( long "client"
                                <> metavar "STRING"
                              )