lib/Hcompta/Lib/Path.hs

   1 module Hcompta.Lib.Path where
   2
   3 import           Control.Applicative ((<$>))
   4 import           Control.Monad (liftM)
   5 import           Control.Monad.IO.Class (liftIO)
   6 import           System.Directory (getHomeDirectory)
   7 import           System.FilePath ((</>))
   8 import qualified System.FilePath.Posix as Path
   9
  10 -- | Return an absolute 'FilePath', given the current working directory and a path.
  11 --
  12 --   * "~" as prefix is expanded to the process's user's home directory
  13 --   * "-" as path is unchanged
  14 --   * ~USER is not supported
  15 abs :: FilePath -> FilePath -> IO FilePath
  16 abs _ "-" = return "-"
  17 abs cwd path =
  18         liftM
  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