PGF service: new command: download

This makes it possible to download PGF files from servers where the PGF service
is installed.

I am also considering making commmand=download the default instead of
command=grammar.

src/server/FastCGIUtils.hs

@@ -3,9 +3,8 @@ module FastCGIUtils (--initFastCGI, loopFastCGI,
                      throwCGIError, handleCGIErrors,
                      stderrToFile,logError,
                      outputJSONP,outputEncodedJSONP,
-                     outputPNG,
-                     outputHTML,
-                     outputPlain,
+                     outputPNG,outputBinary,
+                     outputHTML,outputPlain,
                      splitBy) where
 
 import Control.Concurrent
@@ -177,14 +176,19 @@ outputPNG x = do
        setHeader "Content-Type" "image/png"
        outputFPS x
 
+outputBinary :: BS.ByteString -> CGI CGIResult
+outputBinary x = do
+       setHeader "Content-Type" "application/binary"
+       outputFPS x
+
 outputHTML :: String -> CGI CGIResult
 outputHTML x = do
-       setHeader "Content-Type" "text/html"
+       setHeader "Content-Type" "text/html; charset=utf-8"
        outputStrict $ UTF8.encodeString x
 
 outputPlain :: String -> CGI CGIResult
 outputPlain x = do
-       setHeader "Content-Type" "text/plain"
+       setHeader "Content-Type" "text/plain; charset=utf-8"
        outputStrict $ UTF8.encodeString x
 
 outputStrict :: String -> CGI CGIResult

src/server/PGFService.hs

@@ -51,11 +51,12 @@ cgiMain' cache path =
     do pgf <- liftIO $ readCache cache path
        command <- liftM (maybe "grammar" (urlDecodeUnicode . UTF8.decodeString))
                         (getInput "command")
-       pgfMain pgf command
+       pgfMain path pgf command
 
-pgfMain :: PGF -> String -> CGI CGIResult
-pgfMain pgf command =
+pgfMain :: FilePath -> PGF -> String -> CGI CGIResult
+pgfMain path pgf command =
     case command of
+      "download"       -> outputBinary =<< liftIO (BS.readFile path)
       "parse"          -> outputJSONP =<< doParse pgf `fmap` getText `ap` getCat `ap` getFrom `ap` getLimit
       "complete"       -> outputJSONP =<< doComplete pgf `fmap` getText `ap` getCat `ap` getFrom `ap` getLimit
       "linearize"      -> outputJSONP =<< doLinearize pgf `fmap` getTree `ap` getTo