ledger/Hcompta/Ledger/Lib/FilePath.hs

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