git-annex/Utility/Path/Max.hs
Joey Hess 25703e1413
finally really add back custom-setup stanza
Fourth or fifth try at this and finally found a way to make it work.

Absurd amount of busy-work forced on me by change in cabal's behavior.
Split up Utility modules that need posix stuff out of ones used by
Setup. Various other hacks around inability for Setup to use anything
that ifdefs a use of unix.

Probably lost a full day of my life to this.
This is how build systems make their users hate them. Just saying.
2017-12-31 16:36:39 -04:00

40 lines
900 B
Haskell

{- path manipulation
-
- Copyright 2010-2014 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE CPP #-}
{-# OPTIONS_GHC -fno-warn-tabs #-}
module Utility.Path.Max where
import System.FilePath
import Data.List
import Control.Applicative
import Prelude
#ifndef mingw32_HOST_OS
import Utility.Exception
import System.Posix.Files
#endif
{- Maximum size to use for a file in a specified directory.
-
- Many systems have a 255 byte limit to the name of a file,
- so that's taken as the max if the system has a larger limit, or has no
- limit.
-}
fileNameLengthLimit :: FilePath -> IO Int
#ifdef mingw32_HOST_OS
fileNameLengthLimit _ = return 255
#else
fileNameLengthLimit dir = do
-- 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]
#endif