+
+import Control.Exception
+import Data.List
+import System.FilePath
+import System.Directory
+import System.IO
+
+-- Checks that openTempFile returns filenames with the right structure
+main :: IO ()
+main = do
+ fp0 <- otf ".no_prefix.hs"
+ print (".hs" `isSuffixOf` fp0)
+ print (".no_prefix" `isPrefixOf` takeFileName fp0)
+
+ fp1 <- otf "no_suffix"
+ print (not ('.' `elem` fp1))
+ print ("no_suffix" `isPrefixOf` takeFileName fp1)
+
+ fp2 <- otf "one_suffix.hs"
+ print (".hs" `isSuffixOf` fp2)
+ print ("one_suffix" `isPrefixOf` takeFileName fp2)
+
+ fp3 <- otf "two_suffixes.hs.blah"
+ print (".blah" `isSuffixOf` fp3)
+ print ("two_suffixes.hs" `isPrefixOf` takeFileName fp3)
+
+otf :: FilePath -> IO FilePath
+otf fp = do putStrLn fp
+ bracket (openTempFile "." fp)
+ (\(fp', h) -> do hClose h
+ removeFile fp')
+ (\(fp', _) -> case fp' of
+ '.' : '/' : fp'' -> return fp''
+ '.' : '\\' : fp'' -> return fp''
+ _ -> return fp')
+