diff options
Diffstat (limited to 'Utility/Path/AbsRel.hs')
| -rw-r--r-- | Utility/Path/AbsRel.hs | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/Utility/Path/AbsRel.hs b/Utility/Path/AbsRel.hs index 0026bd6..857dd5e 100644 --- a/Utility/Path/AbsRel.hs +++ b/Utility/Path/AbsRel.hs @@ -1,6 +1,6 @@ {- absolute and relative path manipulation - - - Copyright 2010-2020 Joey Hess <id@joeyh.name> + - Copyright 2010-2021 Joey Hess <id@joeyh.name> - - License: BSD-2-clause -} @@ -19,6 +19,7 @@ module Utility.Path.AbsRel ( ) where import System.FilePath.ByteString +import qualified Data.ByteString as B #ifdef mingw32_HOST_OS import System.Directory (getCurrentDirectory) #else @@ -64,22 +65,27 @@ absPath file #endif return $ absPathFrom cwd file -{- Constructs a relative path from the CWD to a file. +{- Constructs the minimal relative path from the CWD to a file. - - For example, assuming CWD is /tmp/foo/bar: - relPathCwdToFile "/tmp/foo" == ".." - relPathCwdToFile "/tmp/foo/bar" == "" + - relPathCwdToFile "../bar/baz" == "baz" -} relPathCwdToFile :: RawFilePath -> IO RawFilePath -relPathCwdToFile f = do +relPathCwdToFile f + -- Optimisation: Avoid doing any IO when the path is relative + -- and does not contain any ".." component. + | isRelative f && not (".." `B.isInfixOf` f) = return f + | otherwise = do #ifdef mingw32_HOST_OS - c <- toRawFilePath <$> getCurrentDirectory + c <- toRawFilePath <$> getCurrentDirectory #else - c <- getWorkingDirectory + c <- getWorkingDirectory #endif - relPathDirToFile c f + relPathDirToFile c f -{- Constructs a relative path from a directory to a file. -} +{- Constructs a minimal relative path from a directory to a file. -} relPathDirToFile :: RawFilePath -> RawFilePath -> IO RawFilePath relPathDirToFile from to = relPathDirToFileAbs <$> absPath from <*> absPath to |