diff options
Diffstat (limited to 'Utility/Path.hs')
| -rw-r--r-- | Utility/Path.hs | 97 |
1 files changed, 63 insertions, 34 deletions
diff --git a/Utility/Path.hs b/Utility/Path.hs index 9035cbc..f3290d8 100644 --- a/Utility/Path.hs +++ b/Utility/Path.hs @@ -1,11 +1,12 @@ {- path manipulation - - - Copyright 2010-2014 Joey Hess <joey@kitenet.net> + - Copyright 2010-2014 Joey Hess <id@joeyh.name> - - License: BSD-2-clause -} {-# LANGUAGE PackageImports, CPP #-} +{-# OPTIONS_GHC -fno-warn-tabs #-} module Utility.Path where @@ -16,19 +17,21 @@ import Data.List import Data.Maybe import Data.Char import Control.Applicative +import Prelude #ifdef mingw32_HOST_OS import qualified System.FilePath.Posix as Posix #else import System.Posix.Files +import Utility.Exception #endif import qualified "MissingH" System.Path as MissingH import Utility.Monad import Utility.UserInfo -{- Simplifies a path, removing any ".." or ".", and removing the trailing - - path separator. +{- Simplifies a path, removing any "." component, collapsing "dir/..", + - and removing the trailing path separator. - - On Windows, preserves whichever style of path separator might be used in - the input FilePaths. This is done because some programs in Windows @@ -47,7 +50,8 @@ simplifyPath path = dropTrailingPathSeparator $ norm c [] = reverse c norm c (p:ps) - | p' == ".." = norm (drop 1 c) ps + | p' == ".." && not (null c) && dropTrailingPathSeparator (c !! 0) /= ".." = + norm (drop 1 c) ps | p' == "." = norm c ps | otherwise = norm (p:c) ps where @@ -65,7 +69,7 @@ absPathFrom :: FilePath -> FilePath -> FilePath absPathFrom dir path = simplifyPath (combine dir path) {- On Windows, this converts the paths to unix-style, in order to run - - MissingH's absNormPath on them. Resulting path will use / separators. -} + - MissingH's absNormPath on them. -} absNormPathUnix :: FilePath -> FilePath -> Maybe FilePath #ifndef mingw32_HOST_OS absNormPathUnix dir path = MissingH.absNormPath dir path @@ -76,27 +80,29 @@ absNormPathUnix dir path = todos <$> MissingH.absNormPath (fromdos dir) (fromdos todos = replace "/" "\\" #endif -{- Returns the parent directory of a path. - - - - To allow this to be easily used in loops, which terminate upon reaching the - - top, the parent of / is "" -} +{- takeDirectory "foo/bar/" is "foo/bar". This instead yields "foo" -} parentDir :: FilePath -> FilePath -parentDir dir - | null dirs = "" - | otherwise = joinDrive drive (join s $ init dirs) +parentDir = takeDirectory . dropTrailingPathSeparator + +{- Just the parent directory of a path, or Nothing if the path has no +- parent (ie for "/" or ".") -} +upFrom :: FilePath -> Maybe FilePath +upFrom dir + | length dirs < 2 = Nothing + | otherwise = Just $ joinDrive drive (intercalate s $ init dirs) where -- on Unix, the drive will be "/" when the dir is absolute, otherwise "" (drive, path) = splitDrive dir dirs = filter (not . null) $ split s path s = [pathSeparator] -prop_parentDir_basics :: FilePath -> Bool -prop_parentDir_basics dir +prop_upFrom_basics :: FilePath -> Bool +prop_upFrom_basics dir | null dir = True - | dir == "/" = parentDir dir == "" - | otherwise = p /= dir + | dir == "/" = p == Nothing + | otherwise = p /= Just dir where - p = parentDir dir + p = upFrom dir {- Checks if the first FilePath is, or could be said to contain the second. - For example, "foo/" contains "foo/bar". Also, "foo", "./foo", "foo/" etc @@ -125,14 +131,25 @@ absPath file = do - relPathCwdToFile "/tmp/foo/bar" == "" -} relPathCwdToFile :: FilePath -> IO FilePath -relPathCwdToFile f = relPathDirToFile <$> getCurrentDirectory <*> absPath f +relPathCwdToFile f = do + c <- getCurrentDirectory + relPathDirToFile c f + +{- Constructs a relative path from a directory to a file. -} +relPathDirToFile :: FilePath -> FilePath -> IO FilePath +relPathDirToFile from to = relPathDirToFileAbs <$> absPath from <*> absPath to -{- Constructs a relative path from a directory to a file. +{- This requires the first path to be absolute, and the + - second path cannot contain ../ or ./ - - - Both must be absolute, and cannot contain .. etc. (eg use absPath first). + - On Windows, if the paths are on different drives, + - a relative path is not possible and the path is simply + - returned as-is. -} -relPathDirToFile :: FilePath -> FilePath -> FilePath -relPathDirToFile from to = join s $ dotdots ++ uncommon +relPathDirToFileAbs :: FilePath -> FilePath -> FilePath +relPathDirToFileAbs from to + | takeDrive from /= takeDrive to = to + | otherwise = intercalate s $ dotdots ++ uncommon where s = [pathSeparator] pfrom = split s from @@ -145,10 +162,11 @@ relPathDirToFile from to = join s $ dotdots ++ uncommon prop_relPathDirToFile_basics :: FilePath -> FilePath -> Bool prop_relPathDirToFile_basics from to + | null from || null to = True | from == to = null r | otherwise = not (null r) where - r = relPathDirToFile from to + r = relPathDirToFileAbs from to prop_relPathDirToFile_regressionTest :: Bool prop_relPathDirToFile_regressionTest = same_dir_shortcurcuits_at_difference @@ -157,22 +175,31 @@ prop_relPathDirToFile_regressionTest = same_dir_shortcurcuits_at_difference - location, but it's not really the same directory. - Code used to get this wrong. -} same_dir_shortcurcuits_at_difference = - relPathDirToFile (joinPath [pathSeparator : "tmp", "r", "lll", "xxx", "yyy", "18"]) + relPathDirToFileAbs (joinPath [pathSeparator : "tmp", "r", "lll", "xxx", "yyy", "18"]) (joinPath [pathSeparator : "tmp", "r", ".git", "annex", "objects", "18", "gk", "SHA256-foo", "SHA256-foo"]) == joinPath ["..", "..", "..", "..", ".git", "annex", "objects", "18", "gk", "SHA256-foo", "SHA256-foo"] {- Given an original list of paths, and an expanded list derived from it, - - generates a list of lists, where each sublist corresponds to one of the - - original paths. When the original path is a directory, any items - - in the expanded list that are contained in that directory will appear in - - its segment. + - which may be arbitrarily reordered, generates a list of lists, where + - each sublist corresponds to one of the original paths. + - + - When the original path is a directory, any items in the expanded list + - that are contained in that directory will appear in its segment. + - + - The order of the original list of paths is attempted to be preserved in + - the order of the returned segments. However, doing so has a O^NM + - growth factor. So, if the original list has more than 100 paths on it, + - we stop preserving ordering at that point. Presumably a user passing + - that many paths in doesn't care too much about order of the later ones. -} segmentPaths :: [FilePath] -> [FilePath] -> [[FilePath]] segmentPaths [] new = [new] segmentPaths [_] new = [new] -- optimisation -segmentPaths (l:ls) new = [found] ++ segmentPaths ls rest +segmentPaths (l:ls) new = found : segmentPaths ls rest where - (found, rest)=partition (l `dirContains`) new + (found, rest) = if length ls < 100 + then partition (l `dirContains`) new + else break (\p -> not (l `dirContains` p)) new {- This assumes that it's cheaper to call segmentPaths on the result, - than it would be to run the action separately with each path. In @@ -186,7 +213,7 @@ relHome :: FilePath -> IO String relHome path = do home <- myHomeDir return $ if dirContains home path - then "~/" ++ relPathDirToFile home path + then "~/" ++ relPathDirToFileAbs home path else path {- Checks if a command is available in PATH. @@ -255,11 +282,12 @@ fileNameLengthLimit :: FilePath -> IO Int fileNameLengthLimit _ = return 255 #else fileNameLengthLimit dir = do - l <- fromIntegral <$> getPathVar dir FileNameLimit + -- getPathVar can fail due to statfs(2) overflow + l <- catchDefaultIO 0 $ + fromIntegral <$> getPathVar dir FileNameLimit if l <= 0 then return 255 else return $ minimum [l, 255] - where #endif {- Given a string that we'd like to use as the basis for FilePath, but that @@ -267,7 +295,8 @@ fileNameLengthLimit dir = do - sane FilePath. - - All spaces and punctuation and other wacky stuff are replaced - - with '_', except for '.' "../" will thus turn into ".._", which is safe. + - with '_', except for '.' + - "../" will thus turn into ".._", which is safe. -} sanitizeFilePath :: String -> FilePath sanitizeFilePath = map sanitize |