git-annex/Utility/Shell.hs
Joey Hess 1ff889e456
explict export lists
A small amount of dead code removed.

All of Utility/ done now.

This commit was sponsored by Brock Spratlen on Patreon.
2019-11-23 11:24:10 -04:00

58 lines
1.2 KiB
Haskell

{- /bin/sh handling
-
- Copyright 2013 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE CPP #-}
module Utility.Shell (
shellPath,
shebang,
findShellCommand,
) where
import Utility.SafeCommand
#ifdef mingw32_HOST_OS
import Utility.Path
import Utility.Exception
import Utility.PartialPrelude
#endif
#ifdef mingw32_HOST_OS
import System.FilePath
#endif
shellPath :: FilePath
shellPath = "/bin/sh"
shebang :: String
shebang = "#!" ++ shellPath
-- | On Windows, shebang is not handled by the kernel, so to support
-- shell scripts etc, have to look at the program being run and
-- parse it for shebang.
--
-- This has no effect on Unix.
findShellCommand :: FilePath -> IO (FilePath, [CommandParam])
findShellCommand f = do
#ifndef mingw32_HOST_OS
defcmd
#else
l <- catchDefaultIO Nothing $ headMaybe . lines <$> readFile f
case l of
Just ('#':'!':rest) -> case words rest of
[] -> defcmd
(c:ps) -> do
let ps' = map Param ps ++ [File f]
-- If the command is not inPath,
-- take the base of it, and run eg "sh"
-- which in some cases on windows will work
-- despite it not being inPath.
ok <- inPath c
return (if ok then c else takeFileName c, ps')
_ -> defcmd
#endif
where
defcmd = return (f, [])