From a4f3e112954e1b785c84c339bcbd83597a89335e Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Tue, 3 Dec 2013 15:02:21 -0400 Subject: git-repair (1.20131203) unstable; urgency=low * Fix build deps. Closes: #731179 # imported from the archive --- Utility/FileMode.hs | 142 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 Utility/FileMode.hs (limited to 'Utility/FileMode.hs') diff --git a/Utility/FileMode.hs b/Utility/FileMode.hs new file mode 100644 index 0000000..46c6a31 --- /dev/null +++ b/Utility/FileMode.hs @@ -0,0 +1,142 @@ +{- File mode utilities. + - + - Copyright 2010-2012 Joey Hess + - + - Licensed under the GNU GPL version 3 or higher. + -} + +{-# LANGUAGE CPP #-} + +module Utility.FileMode where + +import Common + +import Control.Exception (bracket) +import System.PosixCompat.Types +#ifndef mingw32_HOST_OS +import System.Posix.Files +#endif +import Foreign (complement) + +{- Applies a conversion function to a file's mode. -} +modifyFileMode :: FilePath -> (FileMode -> FileMode) -> IO () +modifyFileMode f convert = void $ modifyFileMode' f convert +modifyFileMode' :: FilePath -> (FileMode -> FileMode) -> IO FileMode +modifyFileMode' f convert = do + s <- getFileStatus f + let old = fileMode s + let new = convert old + when (new /= old) $ + setFileMode f new + return old + +{- Adds the specified FileModes to the input mode, leaving the rest + - unchanged. -} +addModes :: [FileMode] -> FileMode -> FileMode +addModes ms m = combineModes (m:ms) + +{- Removes the specified FileModes from the input mode. -} +removeModes :: [FileMode] -> FileMode -> FileMode +removeModes ms m = m `intersectFileModes` complement (combineModes ms) + +{- Runs an action after changing a file's mode, then restores the old mode. -} +withModifiedFileMode :: FilePath -> (FileMode -> FileMode) -> IO a -> IO a +withModifiedFileMode file convert a = bracket setup cleanup go + where + setup = modifyFileMode' file convert + cleanup oldmode = modifyFileMode file (const oldmode) + go _ = a + +writeModes :: [FileMode] +writeModes = [ownerWriteMode, groupWriteMode, otherWriteMode] + +readModes :: [FileMode] +readModes = [ownerReadMode, groupReadMode, otherReadMode] + +executeModes :: [FileMode] +executeModes = [ownerExecuteMode, groupExecuteMode, otherExecuteMode] + +{- Removes the write bits from a file. -} +preventWrite :: FilePath -> IO () +preventWrite f = modifyFileMode f $ removeModes writeModes + +{- Turns a file's owner write bit back on. -} +allowWrite :: FilePath -> IO () +allowWrite f = modifyFileMode f $ addModes [ownerWriteMode] + +{- Turns a file's owner read bit back on. -} +allowRead :: FilePath -> IO () +allowRead f = modifyFileMode f $ addModes [ownerReadMode] + +{- Allows owner and group to read and write to a file. -} +groupSharedModes :: [FileMode] +groupSharedModes = + [ ownerWriteMode, groupWriteMode + , ownerReadMode, groupReadMode + ] + +groupWriteRead :: FilePath -> IO () +groupWriteRead f = modifyFileMode f $ addModes groupSharedModes + +checkMode :: FileMode -> FileMode -> Bool +checkMode checkfor mode = checkfor `intersectFileModes` mode == checkfor + +{- Checks if a file mode indicates it's a symlink. -} +isSymLink :: FileMode -> Bool +#ifdef mingw32_HOST_OS +isSymLink _ = False +#else +isSymLink = checkMode symbolicLinkMode +#endif + +{- Checks if a file has any executable bits set. -} +isExecutable :: FileMode -> Bool +isExecutable mode = combineModes executeModes `intersectFileModes` mode /= 0 + +{- Runs an action without that pesky umask influencing it, unless the + - passed FileMode is the standard one. -} +noUmask :: FileMode -> IO a -> IO a +#ifndef mingw32_HOST_OS +noUmask mode a + | mode == stdFileMode = a + | otherwise = bracket setup cleanup go + where + setup = setFileCreationMask nullFileMode + cleanup = setFileCreationMask + go _ = a +#else +noUmask _ a = a +#endif + +combineModes :: [FileMode] -> FileMode +combineModes [] = undefined +combineModes [m] = m +combineModes (m:ms) = foldl unionFileModes m ms + +isSticky :: FileMode -> Bool +#ifdef mingw32_HOST_OS +isSticky _ = False +#else +isSticky = checkMode stickyMode + +stickyMode :: FileMode +stickyMode = 512 + +setSticky :: FilePath -> IO () +setSticky f = modifyFileMode f $ addModes [stickyMode] +#endif + +{- Writes a file, ensuring that its modes do not allow it to be read + - by anyone other than the current user, before any content is written. + - + - On a filesystem that does not support file permissions, this is the same + - as writeFile. + -} +writeFileProtected :: FilePath -> String -> IO () +writeFileProtected file content = do + h <- openFile file WriteMode + void $ tryIO $ + modifyFileMode file $ + removeModes [groupReadMode, otherReadMode] + hPutStr h content + hClose h -- cgit v1.2.3