ghc/tests/io/should_run/io016.hs

   1 import IO
   2
   3 import System (getArgs)
   4 import Char   (toUpper)
   5 import Directory (removeFile, doesFileExist)
   6
   7 main   =  getArgs                           >>=        \ [f1,f2] ->
   8           openFile f1 ReadMode              >>=        \ h1      ->
   9           doesFileExist f2                  >>=        \ f       ->
  10           if f then removeFile f2 else return () >>
  11           openFile f2 WriteMode             >>=        \ h2      ->
  12           copyFile h1 h2                    >>
  13           hClose h1                         >>
  14           hClose h2
  15
  16 copyFile h1 h2 =
  17           hIsEOF h1                         >>=        \ eof ->
  18           if eof then
  19             return ()
  20           else
  21             hGetChar h1                     >>=        \ c       ->
  22             hPutChar h2 (toUpper c)         >>
  23             copyFile h1 h2
  24