Added proper command line parsing

shellcheck.hs

@@ -19,11 +19,49 @@ import Control.Monad
 import GHC.Exts
 import GHC.IO.Device
 import ShellCheck.Simple
+import System.Console.GetOpt
 import System.Directory
 import System.Environment
 import System.Exit
 import System.IO
+import qualified Data.Map as Map
 
+data Flag = Flag String String
+
+header = "Usage: shellcheck [OPTIONS...] FILES..."
+options = [
+    Option ['f'] ["format"]
+        (ReqArg (Flag "format") "FORMAT") "output format"
+    ]
+
+printErr = hPutStrLn stderr
+
+parseArguments argv =
+    case getOpt Permute options argv of
+        (opts, files, []) ->
+            if not $ null files
+              then
+                return $ Just (opts, map specials files)
+              else do
+                printErr "No files specified.\n"
+                printErr $ usageInfo header options
+                return $ Nothing
+
+        (_, _, errors) -> do
+            printErr $ (unlines errors) ++ "\n" ++ usageInfo header options
+            return Nothing
+  where
+    specials "-" = "/dev/stdin"
+    specials x = x
+
+formats = Map.fromList [
+    ("tty", forTty)
+    ]
+
+forTty options files = do
+    output <- mapM doFile files
+    return $ and output
+  where
     clear = ansi 0
     ansi n = "\x1B[" ++ (show n) ++ "m"
 
@@ -37,21 +75,23 @@ colorForLevel _ = 0 -- none
 
     colorComment level comment = (ansi $ colorForLevel level) ++ comment ++ clear
 
-doFile path colorFunc = do
+    doFile path = do
         let actualPath = if path == "-" then "/dev/stdin" else path
         exists <- doesFileExist actualPath
         if exists then do
             contents <- readFile actualPath
-        doInput path contents colorFunc
+            doInput path contents
           else do
-        hPutStrLn stderr (colorFunc "error" $ "No such file: " ++ actualPath)
+            colorFunc <- getColorFunc
+            printErr (colorFunc "error" $ "No such file: " ++ actualPath)
             return False
 
-doInput filename contents colorFunc = do
+    doInput filename contents = do
         let fileLines = lines contents
         let lineCount = length fileLines
         let comments = shellCheck contents
         let groups = groupWith scLine comments
+        colorFunc <- getColorFunc
         mapM_ (\x -> do
             let lineNum = scLine (head x)
             let line = if lineNum < 1 || lineNum > lineCount
@@ -74,14 +114,26 @@ getColorFunc = do
         term <- hIsTerminalDevice stdout
         return $ if term then colorComment else const id
 
+getOption [] _ def = def
+getOption ((Flag var val):_) name _ | name == var = val
+getOption (_:rest) flag def = getOption rest flag def
+
 main = do
     args <- getArgs
-    colors <- getColorFunc
+    parsedArgs <- parseArguments args
-    if null args then do
+    status <- process parsedArgs
-        hPutStrLn stderr "shellcheck -- bash/sh script static analysis tool"
+    if status then exitSuccess else exitFailure
-        hPutStrLn stderr "Usage: shellcheck filenames..."
+
-        exitFailure
+process Nothing = return False
-      else do
+process (Just (options, files)) =
-        statuses <- mapM (\f -> doFile f colors) args
+  let format = getOption options "format" "tty" in
-        if and statuses then exitSuccess else exitFailure
+    case Map.lookup format formats of
+        Nothing -> do
+            printErr $ "Unknown format " ++ format
+            printErr $ "Supported formats:"
+            mapM_ (printErr . write) $ Map.keys formats
+            return False
+          where write s = "  " ++ s
+        Just f -> do
+            f options files