src/Main.hs: if no input file is given, read from stdin

This change makes it play nicely as a Unix program that consumes
streams of bytes. One possible usage is to do a 'curl' of the torrent
file and pipe into the functorrent program.

diff --git a/src/Main.hs b/src/Main.hs
index 12af02e5aa7a97aa4b00089416e8a9fe2da71a1a..867e96268a8e787a2d503666365eabd067025827 100644 (file)
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,8 +1,8 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Main where
 
-import Prelude hiding (log, length, readFile)
-import Data.ByteString.Char8 (ByteString, readFile, unpack)
+import Prelude hiding (log, length, readFile, getContents)
+import Data.ByteString.Char8 (ByteString, getContents, readFile, unpack)
 import System.Environment (getArgs)
 import System.Exit (exitSuccess)
 import System.Directory (doesFileExist)
@@ -25,7 +25,7 @@ usage :: IO ()
 usage = putStrLn "usage: functorrent torrent-file"
 
 parse :: [String] -> IO ByteString
-parse [] = usage >> exit
+parse [] = getContents
 parse [a] = do
   fileExist <- doesFileExist a
   if fileExist