lib/Hcompta/Lib/Path.hs

   1 module Hcompta.Lib.Path where
   2
   3 import           Control.Applicative ((<$>))
   4 import           Control.Monad (Monad(..), liftM)
   5 import           Control.Monad.IO.Class (liftIO)
   6 import           Prelude (($), FilePath, IO, id)
   7 import           System.Directory (getHomeDirectory)
   8 import           System.FilePath ((</>))
   9 import qualified System.FilePath.Posix as Path
  10
  11
  12 -- | Return an absolute 'FilePath', given the current working directory and a path.
  13 --
  14 --   * "~" as prefix is expanded to the process's user's home directory
  15 --   * "-" as path is unchanged
  16 --   * ~USER is not supported
  17 abs :: FilePath -> FilePath -> IO FilePath
  18 abs _ "-" = return "-"
  19 abs cwd path =
  20         liftM
  21          (if Path.isRelative path
  22                 then (cwd </>)
  23                 else id)
  24          (expand path)
  25         where
  26                 expand :: FilePath -> IO FilePath
  27                 expand ('~':sep:p) =
  28                         if Path.isPathSeparator sep
  29                         then liftIO $ (</> p) <$> getHomeDirectory
  30                         else fail "~USERNAME in path is not supported"
  31                 expand p = return p