[Haskell-cafe] How to write elegant Haskell programms? (long posting)

[Eric Mertens]

-- Here's my contribution to the "Haskell" way to do it

import Directory (renameFile)
import System.FilePath
import System.Path.Glob (glob)
import System.Time

basenames    = [ "mail.log", "thttpd.log" ]
logdir      = "/var/log"
archivedir  = "/var/log/archive"

main = forM_ bases $ \base -> do
    olds <- glob $ logdir </> base <.> "*.gz"
    forM_ olds $ \old -> do
      now <- timestamp old
      let new = archivedir </> basename <.> now <.> "gz"
      printf "mv %s %s" old new
      renameFile old new

timestamp f = do
    t <- getModificationTime
    return $ formatCalendarTime defaultTimeLocale "%Y%m%d" (toUTCTime t)