354c5f349b
This is essentially the same as withSystemTempFile from System.IO.Temp, but that library is not packaged for Debian, and may not be widely used. I see various other withTempFile implementations here and there, none canonical. Sigh.
307 lines
9 KiB
Haskell
307 lines
9 KiB
Haskell
{- general purpose utility functions
|
|
-
|
|
- Copyright 2010-2011 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Utility (
|
|
CommandParam(..),
|
|
toCommand,
|
|
hGetContentsStrict,
|
|
readFileStrict,
|
|
parentDir,
|
|
absPath,
|
|
absPathFrom,
|
|
relPathCwdToFile,
|
|
relPathDirToFile,
|
|
boolSystem,
|
|
boolSystemEnv,
|
|
executeFile,
|
|
shellEscape,
|
|
shellUnEscape,
|
|
unsetFileMode,
|
|
readMaybe,
|
|
viaTmp,
|
|
withTempFile,
|
|
dirContains,
|
|
dirContents,
|
|
myHomeDir,
|
|
catchBool,
|
|
whenM,
|
|
(>>?),
|
|
unlessM,
|
|
(>>!),
|
|
|
|
prop_idempotent_shellEscape,
|
|
prop_idempotent_shellEscape_multiword,
|
|
prop_parentDir_basics,
|
|
prop_relPathDirToFile_basics
|
|
) where
|
|
|
|
import IO (bracket)
|
|
import System.IO
|
|
import System.Exit
|
|
import qualified System.Posix.Process
|
|
import System.Posix.Process hiding (executeFile)
|
|
import System.Posix.Signals
|
|
import System.Posix.Files
|
|
import System.Posix.Types
|
|
import System.Posix.User
|
|
import Data.String.Utils
|
|
import System.Path
|
|
import System.FilePath
|
|
import System.Directory
|
|
import Foreign (complement)
|
|
import Data.List
|
|
import Data.Maybe
|
|
import Control.Monad (liftM2, when, unless)
|
|
import System.Log.Logger
|
|
|
|
{- A type for parameters passed to a shell command. A command can
|
|
- be passed either some Params (multiple parameters can be included,
|
|
- whitespace-separated, or a single Param (for when parameters contain
|
|
- whitespace), or a File.
|
|
-}
|
|
data CommandParam = Params String | Param String | File FilePath
|
|
deriving (Eq, Show, Ord)
|
|
|
|
{- Used to pass a list of CommandParams to a function that runs
|
|
- a command and expects Strings. -}
|
|
toCommand :: [CommandParam] -> [String]
|
|
toCommand = (>>= unwrap)
|
|
where
|
|
unwrap (Param s) = [s]
|
|
unwrap (Params s) = filter (not . null) (split " " s)
|
|
-- Files that start with a dash are modified to avoid
|
|
-- the command interpreting them as options.
|
|
unwrap (File ('-':s)) = ["./-" ++ s]
|
|
unwrap (File s) = [s]
|
|
|
|
{- Run a system command, and returns True or False
|
|
- if it succeeded or failed.
|
|
-
|
|
- SIGINT(ctrl-c) is allowed to propigate and will terminate the program.
|
|
-}
|
|
boolSystem :: FilePath -> [CommandParam] -> IO Bool
|
|
boolSystem command params = boolSystemEnv command params Nothing
|
|
|
|
boolSystemEnv :: FilePath -> [CommandParam] -> Maybe [(String, String)] -> IO Bool
|
|
boolSystemEnv command params env = do
|
|
-- Going low-level because all the high-level system functions
|
|
-- block SIGINT etc. We need to block SIGCHLD, but allow
|
|
-- SIGINT to do its default program termination.
|
|
let sigset = addSignal sigCHLD emptySignalSet
|
|
oldint <- installHandler sigINT Default Nothing
|
|
oldset <- getSignalMask
|
|
blockSignals sigset
|
|
childpid <- forkProcess $ childaction oldint oldset
|
|
mps <- getProcessStatus True False childpid
|
|
restoresignals oldint oldset
|
|
case mps of
|
|
Just (Exited ExitSuccess) -> return True
|
|
_ -> return False
|
|
where
|
|
restoresignals oldint oldset = do
|
|
_ <- installHandler sigINT oldint Nothing
|
|
setSignalMask oldset
|
|
childaction oldint oldset = do
|
|
restoresignals oldint oldset
|
|
executeFile command True (toCommand params) env
|
|
|
|
{- executeFile with debug logging -}
|
|
executeFile :: FilePath -> Bool -> [String] -> Maybe [(String, String)] -> IO ()
|
|
executeFile c path p e = do
|
|
debugM "Utility.executeFile" $
|
|
"Running: " ++ c ++ " " ++ show p ++ " " ++ maybe "" show e
|
|
System.Posix.Process.executeFile c path p e
|
|
|
|
{- Escapes a filename or other parameter to be safely able to be exposed to
|
|
- the shell. -}
|
|
shellEscape :: String -> String
|
|
shellEscape f = "'" ++ escaped ++ "'"
|
|
where
|
|
-- replace ' with '"'"'
|
|
escaped = join "'\"'\"'" $ split "'" f
|
|
|
|
{- Unescapes a set of shellEscaped words or filenames. -}
|
|
shellUnEscape :: String -> [String]
|
|
shellUnEscape [] = []
|
|
shellUnEscape s = word : shellUnEscape rest
|
|
where
|
|
(word, rest) = findword "" s
|
|
findword w [] = (w, "")
|
|
findword w (c:cs)
|
|
| c == ' ' = (w, cs)
|
|
| c == '\'' = inquote c w cs
|
|
| c == '"' = inquote c w cs
|
|
| otherwise = findword (w++[c]) cs
|
|
inquote _ w [] = (w, "")
|
|
inquote q w (c:cs)
|
|
| c == q = findword w cs
|
|
| otherwise = inquote q (w++[c]) cs
|
|
|
|
{- For quickcheck. -}
|
|
prop_idempotent_shellEscape :: String -> Bool
|
|
prop_idempotent_shellEscape s = [s] == (shellUnEscape . shellEscape) s
|
|
prop_idempotent_shellEscape_multiword :: [String] -> Bool
|
|
prop_idempotent_shellEscape_multiword s = s == (shellUnEscape . unwords . map shellEscape) s
|
|
|
|
{- A version of hgetContents that is not lazy. Ensures file is
|
|
- all read before it gets closed. -}
|
|
hGetContentsStrict :: Handle -> IO String
|
|
hGetContentsStrict h = hGetContents h >>= \s -> length s `seq` return s
|
|
|
|
{- A version of readFile that is not lazy. -}
|
|
readFileStrict :: FilePath -> IO String
|
|
readFileStrict f = readFile f >>= \s -> length s `seq` return s
|
|
|
|
{- Returns the parent directory of a path. Parent of / is "" -}
|
|
parentDir :: FilePath -> FilePath
|
|
parentDir dir =
|
|
if not $ null dirs
|
|
then slash ++ join s (take (length dirs - 1) dirs)
|
|
else ""
|
|
where
|
|
dirs = filter (not . null) $ split s dir
|
|
slash = if isAbsolute dir then s else ""
|
|
s = [pathSeparator]
|
|
|
|
prop_parentDir_basics :: FilePath -> Bool
|
|
prop_parentDir_basics dir
|
|
| null dir = True
|
|
| dir == "/" = parentDir dir == ""
|
|
| otherwise = p /= dir
|
|
where
|
|
p = parentDir 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
|
|
- are all equivilant.
|
|
-}
|
|
dirContains :: FilePath -> FilePath -> Bool
|
|
dirContains a b = a == b || a' == b' || (a'++"/") `isPrefixOf` b'
|
|
where
|
|
norm p = fromMaybe "" $ absNormPath p "."
|
|
a' = norm a
|
|
b' = norm b
|
|
|
|
{- Converts a filename into a normalized, absolute path. -}
|
|
absPath :: FilePath -> IO FilePath
|
|
absPath file = do
|
|
cwd <- getCurrentDirectory
|
|
return $ absPathFrom cwd file
|
|
|
|
{- Converts a filename into a normalized, absolute path
|
|
- from the specified cwd. -}
|
|
absPathFrom :: FilePath -> FilePath -> FilePath
|
|
absPathFrom cwd file = fromMaybe bad $ absNormPath cwd file
|
|
where
|
|
bad = error $ "unable to normalize " ++ file
|
|
|
|
{- Constructs a relative path from the CWD to a file.
|
|
-
|
|
- For example, assuming CWD is /tmp/foo/bar:
|
|
- relPathCwdToFile "/tmp/foo" == ".."
|
|
- relPathCwdToFile "/tmp/foo/bar" == ""
|
|
-}
|
|
relPathCwdToFile :: FilePath -> IO FilePath
|
|
relPathCwdToFile f = liftM2 relPathDirToFile getCurrentDirectory (absPath f)
|
|
|
|
{- Constructs a relative path from a directory to a file.
|
|
-
|
|
- Both must be absolute, and normalized (eg with absNormpath).
|
|
-}
|
|
relPathDirToFile :: FilePath -> FilePath -> FilePath
|
|
relPathDirToFile from to = path
|
|
where
|
|
s = [pathSeparator]
|
|
pfrom = split s from
|
|
pto = split s to
|
|
common = map fst $ filter same $ zip pfrom pto
|
|
same (c,d) = c == d
|
|
uncommon = drop numcommon pto
|
|
dotdots = replicate (length pfrom - numcommon) ".."
|
|
numcommon = length common
|
|
path = join s $ dotdots ++ uncommon
|
|
|
|
prop_relPathDirToFile_basics :: FilePath -> FilePath -> Bool
|
|
prop_relPathDirToFile_basics from to
|
|
| from == to = null r
|
|
| otherwise = not (null r)
|
|
where
|
|
r = relPathDirToFile from to
|
|
|
|
{- Removes a FileMode from a file.
|
|
- For example, call with otherWriteMode to chmod o-w -}
|
|
unsetFileMode :: FilePath -> FileMode -> IO ()
|
|
unsetFileMode f m = do
|
|
s <- getFileStatus f
|
|
setFileMode f $ fileMode s `intersectFileModes` complement m
|
|
|
|
{- Attempts to read a value from a String. -}
|
|
readMaybe :: (Read a) => String -> Maybe a
|
|
readMaybe s = case reads s of
|
|
((x,_):_) -> Just x
|
|
_ -> Nothing
|
|
|
|
{- Runs an action like writeFile, writing to a tmp file first and
|
|
- then moving it into place. -}
|
|
viaTmp :: (FilePath -> String -> IO ()) -> FilePath -> String -> IO ()
|
|
viaTmp a file content = do
|
|
pid <- getProcessID
|
|
let tmpfile = file ++ ".tmp" ++ show pid
|
|
createDirectoryIfMissing True (parentDir file)
|
|
a tmpfile content
|
|
renameFile tmpfile file
|
|
|
|
{- Runs an action with a temp file, then removes the file. -}
|
|
withTempFile :: String -> (FilePath -> Handle -> IO a) -> IO a
|
|
withTempFile template action = bracket create remove use
|
|
where
|
|
create = do
|
|
tmpdir <- catch getTemporaryDirectory (const $ return ".")
|
|
openTempFile tmpdir template
|
|
remove (name, handle) = do
|
|
hClose handle
|
|
catchBool (removeFile name >> return True)
|
|
use (name, handle) = action name handle
|
|
|
|
{- Lists the contents of a directory.
|
|
- Unlike getDirectoryContents, paths are not relative to the directory. -}
|
|
dirContents :: FilePath -> IO [FilePath]
|
|
dirContents d = do
|
|
c <- getDirectoryContents d
|
|
return $ map (d </>) $ filter notcruft c
|
|
where
|
|
notcruft "." = False
|
|
notcruft ".." = False
|
|
notcruft _ = True
|
|
|
|
{- Current user's home directory. -}
|
|
myHomeDir :: IO FilePath
|
|
myHomeDir = do
|
|
uid <- getEffectiveUserID
|
|
u <- getUserEntryForID uid
|
|
return $ homeDirectory u
|
|
|
|
{- Catches IO errors and returns a Bool -}
|
|
catchBool :: IO Bool -> IO Bool
|
|
catchBool = flip catch (const $ return False)
|
|
|
|
{- when with a monadic conditional -}
|
|
whenM :: Monad m => m Bool -> m () -> m ()
|
|
whenM c a = c >>= flip when a
|
|
|
|
unlessM :: Monad m => m Bool -> m () -> m ()
|
|
unlessM c a = c >>= flip unless a
|
|
|
|
(>>?) :: Monad m => m Bool -> m () -> m ()
|
|
(>>?) = whenM
|
|
|
|
(>>!) :: Monad m => m Bool -> m () -> m ()
|
|
(>>!) = unlessM
|
|
|
|
-- low fixity allows eg, foo bar >>! error $ "failed " ++ meep
|
|
infixr 0 >>?
|
|
infixr 0 >>!
|