-import IO -- 1.3
+import IO
import System (getArgs)
import Char (toUpper)
+import Directory (removeFile, doesFileExist)
main = getArgs >>= \ [f1,f2] ->
openFile f1 ReadMode >>= \ h1 ->
+ doesFileExist f2 >>= \ f ->
+ if f then removeFile f2 else return () >>
openFile f2 WriteMode >>= \ h2 ->
copyFile h1 h2 >>
hClose h1 >>