Working on URL resolution and meta data handling

app/gnuplot.hs

 #!/usr/bin/env runhaskell
 {-# LANGUAGE OverloadedStrings #-}
--- gnuplot.hs
 
+-- gnuplot.hs
 module Main where
 
-import Text.Pandoc.JSON
-import System.Process
-import System.IO
-import System.Exit
-import System.Directory
+import qualified Data.ByteString.Base64 as B64
 import qualified Data.ByteString.Char8 as B
 import qualified Data.ByteString.Lazy.Char8 as L
 import Data.Digest.Pure.MD5
 import Data.List
 import Data.List.Split
-import qualified Data.ByteString.Base64 as B64
+import System.Directory
+import System.Exit
+import System.IO
+import System.Process
+import Text.Pandoc.JSON
 
 -- Compiles an external Gnuplot file to an external PDF file. Returns the name of
 -- the PDF file or an error message.
 compileExternal :: String -> String -> IO (Either String String)
-
 compileExternal cmd infile = do
   let outfile = (Prelude.head (splitOn "." infile)) ++ ".pdf"
   let prelude = "set terminal pdfcairo; set output '" ++ outfile ++ "';"
-  (exitCode, _, err) <- readProcessWithExitCode "gnuplot" ["-d", "-e", prelude, infile] ""
+  (exitCode, _, err) <-
+    readProcessWithExitCode "gnuplot" ["-d", "-e", prelude, infile] ""
   if exitCode == ExitSuccess
-  then return (Right outfile)
-  else return (Left err)
+    then return (Right outfile)
+    else return (Left err)
 
 genUniqueFilename :: String -> String -> String -> FilePath
 genUniqueFilename prefix contents extension =
-    prefix ++ "-" ++ (take 8 $ show $ md5 $ L.pack contents) ++ "." ++ extension
+  prefix ++ "-" ++ (take 8 $ show $ md5 $ L.pack contents) ++ "." ++ extension
 
 -- Compiles an embedded Gnuplot description to an external PDF file with a generated filename.
 -- Returns the name of the PDF file or an error message.
 compileInternal :: String -> String -> IO (Either String String)
-
 compileInternal cmd contents = do
   let outfile = genUniqueFilename cmd contents "pdf"
   exists <- doesFileExist outfile
   if exists
-  then return (Right outfile)
-  else do
+    then return (Right outfile)
+    else do
       let prelude = "set terminal pdfcairo; set output '" ++ outfile ++ "';"
-      (exitCode, _, err) <- readProcessWithExitCode "gnuplot" ["-d"] (prelude ++ contents)
+      (exitCode, _, err) <-
+        readProcessWithExitCode "gnuplot" ["-d"] (prelude ++ contents)
       if exitCode == ExitSuccess
-      then return (Right outfile)
-      else return (Left err)
+        then return (Right outfile)
+        else return (Left err)
 
 -- Creates a Pandoc Image block from the filename or communicates an inline error message.
 generateBlock :: (Either String String) -> IO Block
-
 generateBlock (Right filename) = do
   return (Para [Image nullAttr [] (filename, "Generated from code block")])
-
 generateBlock (Left error) = do
   hPutStrLn stderr msg
   return (Para [Str msg])
-         where msg = "Error in filter 'gnuplot': " ++ error
-
--- Compiles gnuplot code from a code block to an image block
-compileGnuplot :: Maybe Format -> Block -> IO Block
+  where
+    msg = "Error in filter 'gnuplot': " ++ error
 
 thrd (_, _, x) = x
 
+-- Compiles gnuplot code from a code block to an image block
+compileGnuplot :: Maybe Format -> Block -> IO Block
 compileGnuplot (Just (Format "latex")) cb@(CodeBlock attribs contents) =
-    case lookup "gnuplot" (thrd attribs) of
-      Just ""     -> compileInternal "gnuplot" contents >>= generateBlock
-      Just infile -> compileExternal "gnuplot" infile >>= generateBlock
-      Nothing                    -> return cb
-
-compileGnuplot (Just (Format "revealjs")) cb@(CodeBlock (id, classes, namevals) contents) =
+  case lookup "gnuplot" (thrd attribs) of
+    Just "block" -> compileInternal "gnuplot" contents >>= generateBlock
+    Just infile -> compileExternal "gnuplot" infile >>= generateBlock
+    Nothing -> return cb
+compileGnuplot (Just (Format "revealjs")) cb@(CodeBlock (id, classes, namevals) contents)
     -- Examine 'dot' attribute.
-    case lookup "dot" namevals of
+ =
+  case lookup "dot" namevals
       -- Empty file name means 'read from code block'.
-      Just "" -> do
+        of
+    Just ""
         -- Pipe content to dot, include result via data
         -- url on an image tag. Otherwise it is difficult to control
         -- the size if the resulting SVG element with CSS.
-        (exitCode, svg, err) <- readProcessWithExitCode "dot" ["-Tsvg"] contents
-        if exitCode == ExitSuccess
-        then return (Para [Image nullAttr [] (svgDataUrl svg, "Generated from code block")])
+     -> do
+      (exitCode, svg, err) <- readProcessWithExitCode "dot" ["-Tsvg"] contents
+      if exitCode == ExitSuccess
+        then return
+               (Para
+                  [ Image
+                      nullAttr
+                      []
+                      (svgDataUrl svg, "Generated from code block")
+                  ])
         else return (Para [Str $ "Error running 'dot': " ++ err])
-
       -- Read from file
-      Just file -> do
-        (exitCode, svg, err) <- readProcessWithExitCode "dot" ["-Tsvg", file] ""
-        if exitCode == ExitSuccess
-        then return (Para [Image nullAttr [] (svgDataUrl svg, "Generated from file " ++ file)])
+    Just file -> do
+      (exitCode, svg, err) <- readProcessWithExitCode "dot" ["-Tsvg", file] ""
+      if exitCode == ExitSuccess
+        then return
+               (Para
+                  [ Image
+                      nullAttr
+                      []
+                      (svgDataUrl svg, "Generated from file " ++ file)
+                  ])
         else return (Para [Str $ "Error running 'dot': " ++ err])
-
       -- Do nothing
-      Nothing -> return cb
-
+    Nothing -> return cb
 compileGnuplot _ cb = return cb
 
 main :: IO ()
@@ -100,4 +109,5 @@ main = toJSONFilter compileGnuplot
 
 -- | Encode a svg snippet into a data url for an image element
 svgDataUrl :: String -> String
-svgDataUrl svg = "data:image/svg+xml;base64," ++ (B.unpack (B64.encode (B.pack svg)))
+svgDataUrl svg =
+  "data:image/svg+xml;base64," ++ (B.unpack (B64.encode (B.pack svg)))

slides.cabal

@@ -15,7 +15,7 @@ cabal-version:       >=1.10
 
 library
   hs-source-dirs:      src
-  exposed-modules:     Watch, Test, Embed, Context, Utilities, Filter, Student, Shuffle
+  exposed-modules:     Watch, Test, Embed, Context, Utilities, Filter, Student, Shuffle, Project
   build-depends:       base
                      , aeson
                      , random
@@ -52,6 +52,7 @@ library
                      , fsnotify
                      , vector
                      , scientific
+                     , transformers
   default-language:    Haskell2010
 
 executable decker
@@ -119,22 +120,22 @@ executable examiner
 --                      , pureMD5
 --   default-language:    Haskell2010
 
--- executable gnuplot-pandoc-filter
---   hs-source-dirs:      app
---   main-is:             Gnuplot.hs
---   ghc-options:         -threaded -rtsopts -with-rtsopts=-N
---   build-depends:       base
---                      , slides
---                      , pandoc-types
---                      , base64-bytestring
---                      , bytestring
---                      , process
---                      , blaze-markup
---                      , blaze-html
---                      , split
---                      , pureMD5
---                      , directory
---   default-language:    Haskell2010
+executable gnuplot-pandoc-filter
+  hs-source-dirs:      app
+  main-is:             Gnuplot.hs
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
+  build-depends:       base
+                     , slides
+                     , pandoc-types
+                     , base64-bytestring
+                     , bytestring
+                     , process
+                     , blaze-markup
+                     , blaze-html
+                     , split
+                     , pureMD5
+                     , directory
+  default-language:    Haskell2010
 
 -- executable macros-pandoc-filter
 --   hs-source-dirs:      app

src/project.hs

+module Project
+  ( provisionResource
+  , removeCommonPrefix
+  , isPrefix
+  ) where
+
+import Control.Monad
+import Control.Monad.Trans.Class
+import Control.Monad.Trans.Maybe
+import Data.Maybe
+import Network.URI
+import System.Directory
+import System.FilePath
+
+data Provisioning
+  = Copy -- Copy to public and relative link
+  | SymbolicLink -- Link to public and relative link
+  | Reference -- Absolute local link
+
+data ResolvedUrl = ResolvedUrl
+  { sourceFile :: FilePath -- Absolute Path to source file
+  , publicFile :: FilePath -- Absolute path to file in public folder
+  , publicUrl :: FilePath -- Relative URL to served file from base
+  }
+
+-- Find the project directory.  
+-- The project directory is the first upwards directory that contains a .git directory entry.
+calcProjectDirectory :: IO FilePath
+calcProjectDirectory = do
+  cwd <- getCurrentDirectory
+  searchGitRoot cwd
+  where
+    searchGitRoot :: FilePath -> IO FilePath
+    searchGitRoot path =
+      if isDrive path
+        then makeAbsolute "."
+        else do
+          hasGit <- doesDirectoryExist (path </> ".git")
+          if hasGit
+            then makeAbsolute path
+            else searchGitRoot $ takeDirectory path
+
+-- Resolves a file path to a concrete verified file system path, or
+-- returns Nothing if no file can be found.
+resolve :: FilePath -> FilePath -> FilePath -> IO (Maybe FilePath)
+resolve project base path = do
+  let pathes =
+        if isAbsolute path
+          then [project </> makeRelative "/" path, path]
+          else [base </> path, project </> path]
+  listToMaybe <$> filterM doesFileExist pathes
+
+resolveUrl :: FilePath -> FilePath -> FilePath -> IO (Maybe ResolvedUrl)
+resolveUrl project base url = do
+  case parseURI url >>= fileOrRelativeUrl of
+    Nothing -> return Nothing
+    Just path -> do
+      file <- resolve project base path
+      case file of
+        Nothing -> return Nothing
+        Just file -> return $ Just $ ResolvedUrl file "" ""
+
+fileOrRelativeUrl :: URI -> Maybe FilePath
+fileOrRelativeUrl (URI "file:" Nothing path _ _) = Just path
+fileOrRelativeUrl (URI "" Nothing path _ _) = Just path
+fileOrRelativeUrl _ = Nothing
+
+-- | Determines if a URL can be resolved to a local file. Absolute file URLs 
+-- are resolved against and copied or linked from 
+--    - the project root 
+--    - the local filesystem root 
+-- Relative file URLs are resolved against and copied or linked from 
+--    - the directory path of the referencing file 
+--    - the project root
+-- Copy and link operations target the public directory in the project root
+-- and recreate the source directory structure.
+provisionResource ::
+     Provisioning -> FilePath -> FilePath -> FilePath -> IO FilePath
+provisionResource provisioning project base path = do
+  let pathes =
+        if isAbsolute path
+          then [project </> makeRelative "/" path, path]
+          else [base </> path, project </> path]
+  resource <- listToMaybe <$> filterM doesFileExist pathes
+  case resource of
+    Nothing -> return path
+    Just resolved -> do
+      case provisioning of
+        Copy -> return resolved
+        SymbolicLink -> return resolved
+        Reference -> return resolved
+
+copyFileChanged :: FilePath -> FilePath -> IO ()
+copyFileChanged src dst = do
+  newer <- fileIsNewer src dst
+  if newer
+    then do
+      createDirectoryIfMissing True (takeDirectory dst)
+      copyFile src dst
+    else return ()
+
+fileIsNewer a b = do
+  exists <- doesFileExist b
+  if exists
+    then do
+      at <- getModificationTime a
+      bt <- getModificationTime b
+      return (at > bt)
+    else return True
+
+-- | Express the second path argument as relative to the first. 
+-- Both arguments are expected to be absolute pathes. 
+makeRelativeTo :: FilePath -> FilePath -> FilePath
+makeRelativeTo dir file =
+  let (d, f) = removeCommonPrefix (dir, file)
+  in normalise $ invertPath d </> f
+
+invertPath :: FilePath -> FilePath
+invertPath fp = joinPath $ map (const "..") $ filter ("." /=) $ splitPath fp
+
+removeCommonPrefix :: (FilePath, FilePath) -> (FilePath, FilePath)
+removeCommonPrefix =
+  mapTuple joinPath . removeCommonPrefix_ . mapTuple splitDirectories
+  where
+    removeCommonPrefix_ :: ([FilePath], [FilePath]) -> ([FilePath], [FilePath])
+    removeCommonPrefix_ (al@(a:as), bl@(b:bs))
+      | a == b = removeCommonPrefix_ (as, bs)
+      | otherwise = (al, bl)
+    removeCommonPrefix_ pathes = pathes
+
+isPrefix a b = isPrefix_ (splitPath a) (splitPath b)
+  where
+    isPrefix_ :: Eq a => [a] -> [a] -> Bool
+    isPrefix_ al@(a:as) bl@(b:bs)
+      | a == b = isPrefix_ as bs
+      | otherwise = False
+    isPrefix_ [] _ = True
+    isPrefix_ _ _ = False
+
+mapTuple f (a, b) = (f a, f b)

src/utilities.hs

@@ -723,6 +723,7 @@ removeCommonPrefix :: [FilePath] -> [FilePath] -> ([FilePath], [FilePath])
 removeCommonPrefix al@(a:as) bl@(b:bs)
   | a == b = removeCommonPrefix as bs
   | otherwise = (al, bl)
+removeCommonPrefix a [] = (a, [])
 removeCommonPrefix [] b = ([], b)
 
 writeExampleProject :: Action ()

test/Spec.hs

@@ -10,6 +10,7 @@ import Data.Text
 import Data.Text.Encoding
 import qualified Data.Yaml as Y
 import NeatInterpolation
+import Project as P
 import Student
 import System.FilePath
 import System.FilePath.Glob
@@ -35,7 +36,7 @@ main = do
       it "returns True if URL has http: or https: protocol" $ do
         isCacheableURI "http://heise.de" `shouldBe` True
         isCacheableURI "ftp://heise.de" `shouldBe` False
-       --
+    --
     describe "adjustLocalUrl" $
       it
         "adjusts URL to be relative to the project root or the provided base directory" $ do
@@ -60,7 +61,15 @@ main = do
           "/Users/henrik/tmp/decker-demo/public"
           "/Users/henrik/tmp/decker-demo/public/cache/b48cadafb942dc1426316772321dd0c7.png" `shouldBe`
           "cache/b48cadafb942dc1426316772321dd0c7.png"
-       --
+    --
+    describe "removeCommonPrefix" $
+      it "Removes the common prefix from two pathes." $ do
+        P.removeCommonPrefix ("", "") `shouldBe` ("", "")
+        P.removeCommonPrefix ("fasel/bla", "fasel/bla/lall") `shouldBe` ("", "lall")
+        P.removeCommonPrefix ("lurgel/hopp", "fasel/bla/lall") `shouldBe` ("lurgel/hopp", "fasel/bla/lall")
+        P.removeCommonPrefix ("/lurgel/hopp", "fasel/bla/lall") `shouldBe` ("/lurgel/hopp", "fasel/bla/lall")
+        P.removeCommonPrefix ("/lurgel/hopp", "/fasel/bla/lall") `shouldBe` ("lurgel/hopp", "fasel/bla/lall")
+    --
     describe "cacheRemoteFile" $
       it
         "Stores the data behind a URL locally, if possible. Return the local path to the cached file." $ do
@@ -106,89 +115,68 @@ main = do
     describe "parseStudentData" $
       it "Parses student data in YAML format into a nifty data structure." $
       parseStudentData projectDir `shouldReturn` Just realData
-    --
-    describe "splitMarkdown" $
-      it "Splits markdown into text und meta data." $ do
-        splitMarkdown "" `shouldBe` ("", Y.Object $ H.fromList [])
-        splitMarkdown "Hällö" `shouldBe` ("Hällö", Y.Object $ H.fromList [])
-        splitMarkdown "---\ntext: Hällö\n---" `shouldBe`
-          ("", Y.Object $ H.fromList [("text", "Hällö")])
-        splitMarkdown "---\ntext: Hallo Wach\n---\nSome more text." `shouldBe`
-          ("Some more text.", Y.Object $ H.fromList [("text", "Hallo Wach")])
-        splitMarkdown
-          "---\ntext: Hallo Wach\n---\nSome more text.\n---\ntoast: Cheese\n---\nSandwich" `shouldBe`
-          ( "Some more text.\n\nSandwich"
-          , Y.Object $ H.fromList [("text", "Hallo Wach"), ("toast", "Cheese")])
-    --
-    describe "toMeta" $
-      it "Converts YAML.Value data to Pandoc.Meta data" $ do
-        toMeta (Y.Object $ H.fromList []) `shouldBe` MetaMap M.empty
-        toMeta (Y.Object $ H.fromList [("test", "Hallo")]) `shouldBe`
-          MetaMap (M.fromList [("test", MetaString "Hallo")])
 
 mockData :: Students
 mockData =
-  Students $
-  H.fromList
-    [ ( "888888"
-      , Student "mock" "mock" "mock" "mock" "mock" "mock" "mock" "mock" 1)
-    , ( "888889"
-      , Student "mock" "mock" "mock" "mock" "mock" "mock" "mock" "mock" 1)
-    ]
+  Students
+  { stds_course = "Mock"
+  , stds_semester = "Mock 1234"
+  , stds_students =
+      H.fromList
+        [ ("888888", Student "mock" "mock" "mock" "mock" "mock" "mock" 1)
+        , ("888889", Student "mock" "mock" "mock" "mock" "mock" "mock" 1)
+        ]
+  }
 
 realData :: Students
 realData =
   Students
-    (H.fromList
-       [ ( "836381"
-         , Student
-           { std_uid = "s64386"
-           , std_department = "FB6"
-           , std_displayName = "Justen, David Alexander"
-           , std_employeeNumber = "836381"
-           , std_givenName = "David Alexander"
-           , std_mail = "s64386@beuth-hochschule.de"
-           , std_sAMAccountName = "s64386"
-           , std_sn = "Justen"
-           , std_track = 1
-           })
-       , ( "798101"
-         , Student
-           { std_uid = "s53445"
-           , std_department = "FB6"
-           , std_displayName = "Mahmoud, Hassan"
-           , std_employeeNumber = "798101"
-           , std_givenName = "Hassan"
-           , std_mail = "s53445@beuth-hochschule.de"
-           , std_sAMAccountName = "s53445"
-           , std_sn = "Mahmoud"
-           , std_track = 1
-           })
-       , ( "814510"
-         , Student
-           { std_uid = "s57637"
-           , std_department = "FB6"
-           , std_displayName = "Sahli, Hanen"
-           , std_employeeNumber = "814510"
-           , std_givenName = "Hanen"
-           , std_mail = "s57637@beuth-hochschule.de"
-           , std_sAMAccountName = "s57637"
-           , std_sn = "Sahli"
-           , std_track = 1
-           })
-       , ( "832701"
-         , Student
-           { std_uid = "s61660"
-           , std_department = "FB6"
-           , std_displayName = "Naci Aydogan"
-           , std_employeeNumber = "832701"
-           , std_givenName = "Naci"
-           , std_mail = "s61660@beuth-hochschule.de"
-           , std_sAMAccountName = "s61660"
-           , std_sn = "Aydogan"
-           , std_track = 1
-           })
-       ])
+  { stds_course = "Mock"
+  , stds_semester = "Mock 1234"
+  , stds_students =
+      (H.fromList
+         [ ( "836381"
+           , Student
+             { std_displayName = "Justen, David Alexander"
+             , std_employeeNumber = "836381"
+             , std_givenName = "David Alexander"
+             , std_mail = "s64386@beuth-hochschule.de"
+             , std_sAMAccountName = "s64386"
+             , std_sn = "Justen"
+             , std_track = 1
+             })
+         , ( "798101"
+           , Student
+             { std_displayName = "Mahmoud, Hassan"
+             , std_employeeNumber = "798101"
+             , std_givenName = "Hassan"
+             , std_mail = "s53445@beuth-hochschule.de"
+             , std_sAMAccountName = "s53445"
+             , std_sn = "Mahmoud"
+             , std_track = 1
+             })
+         , ( "814510"
+           , Student
+             { std_displayName = "Sahli, Hanen"
+             , std_employeeNumber = "814510"
+             , std_givenName = "Hanen"
+             , std_mail = "s57637@beuth-hochschule.de"
+             , std_sAMAccountName = "s57637"
+             , std_sn = "Sahli"
+             , std_track = 1
+             })
+         , ( "832701"
+           , Student
+             { std_displayName = "Naci Aydogan"
+             , std_employeeNumber = "832701"
+             , std_givenName = "Naci"
+             , std_mail = "s61660@beuth-hochschule.de"
+             , std_sAMAccountName = "s61660"
+             , std_sn = "Aydogan"
+             , std_track = 1
+             })
+         ])
+  }
 
 genStudentData :: FilePath -> IO ()
 genStudentData dir =

test/student-mock-data.yaml

-888888:
-  department: mock
-  givenName: mock
-  track: 1
-  uid: mock
-  sAMAccountName: mock
-  displayName: mock
-  sn: mock
-  employeeNumber: mock
-  mail: mock
-888889:
-  department: mock
-  givenName: mock
-  track: 1
-  uid: mock
-  sAMAccountName: mock
-  displayName: mock
-  sn: mock
-  employeeNumber: mock
-  mail: mock
+semester: Mock 1234
+students:
+  888888:
+    givenName: mock
+    track: 1
+    sAMAccountName: mock
+    displayName: mock
+    sn: mock
+    employeeNumber: mock
+    mail: mock
+  888889:
+    givenName: mock
+    track: 1
+    sAMAccountName: mock
+    displayName: mock
+    sn: mock
+    employeeNumber: mock
+    mail: mock
+course: Mock

test/student-test-data.yaml

 {
-  "798101": {
-    "department": "FB6",
-    "displayName": "Mahmoud, Hassan",
-    "employeeNumber": "798101",
-    "givenName": "Hassan",
-    "mail": "s53445@beuth-hochschule.de",
-    "sAMAccountName": "s53445",
-    "sn": "Mahmoud",
-    "uid": "s53445",
-    "track": 1
-  },
-  "814510": {
-    "department": "FB6",
-    "displayName": "Sahli, Hanen",
-    "employeeNumber": "814510",
-    "givenName": "Hanen",
-    "mail": "s57637@beuth-hochschule.de",
-    "sAMAccountName": "s57637",
-    "sn": "Sahli",
-    "uid": "s57637",
-    "track": 1
-  },
-  "832701": {
-    "department": "FB6",
-    "displayName": "Naci Aydogan",
-    "employeeNumber": "832701",
-    "givenName": "Naci",
-    "mail": "s61660@beuth-hochschule.de",
-    "sAMAccountName": "s61660",
-    "sn": "Aydogan",
-    "uid": "s61660",
-    "track": 1
-  },
-  "836381": {
-    "department": "FB6",
-    "displayName": "Justen, David Alexander",
-    "employeeNumber": "836381",
-    "givenName": "David Alexander",
-    "mail": "s64386@beuth-hochschule.de",
-    "sAMAccountName": "s64386",
-    "sn": "Justen",
-    "uid": "s64386",
-    "track": 1
+  "course": "Mock",
+  "semester": "Mock 1234",
+  "students":
+    {
+    "798101": {
+      "displayName": "Mahmoud, Hassan",
+      "employeeNumber": "798101",
+      "givenName": "Hassan",
+      "mail": "s53445@beuth-hochschule.de",
+      "sAMAccountName": "s53445",
+      "sn": "Mahmoud",
+      "track": 1
+    },
+    "814510": {
+      "displayName": "Sahli, Hanen",
+      "employeeNumber": "814510",
+      "givenName": "Hanen",
+      "mail": "s57637@beuth-hochschule.de",
+      "sAMAccountName": "s57637",
+      "sn": "Sahli",
+      "track": 1
+    },
+    "832701": {
+      "displayName": "Naci Aydogan",
+      "employeeNumber": "832701",
+      "givenName": "Naci",
+      "mail": "s61660@beuth-hochschule.de",
+      "sAMAccountName": "s61660",
+      "sn": "Aydogan",
+      "track": 1
+    },
+    "836381": {
+      "displayName": "Justen, David Alexander",
+      "employeeNumber": "836381",
+      "givenName": "David Alexander",
+      "mail": "s64386@beuth-hochschule.de",
+      "sAMAccountName": "s64386",
+      "sn": "Justen",
+      "track": 1
+    }
   }
-}
+}
\ No newline at end of file