Util.hs

module Stack2nix.External.Util where

import           Data.Monoid      ((<>))
import           System.Directory (getCurrentDirectory)
import           System.Exit      (ExitCode (..))
import           System.Process   (CreateProcess (..), proc,
                                   readCreateProcessWithExitCode)

runCmdFrom :: FilePath -> String -> [String] -> IO (ExitCode, String, String)
runCmdFrom dir prog args = readCreateProcessWithExitCode (fromDir dir (proc prog args)) ""
  where
    fromDir :: FilePath -> CreateProcess -> CreateProcess
    fromDir d procDesc = procDesc { cwd = Just d }

runCmd :: String -> [String] -> IO (ExitCode, String, String)
runCmd prog args = getCurrentDirectory >>= (\d -> runCmdFrom d prog args)

failHard :: (ExitCode, String, String) -> IO (ExitCode, String, String)
failHard r@(ExitSuccess, _, _)         = pure r
failHard (ExitFailure code, _, err) =
  error $ unlines [ "Failed with exit code " <> show code <> "..."
                  , show err
                  ]