module Stack.DefaultColorWhen
( defaultColorWhen
) where
import Stack.Prelude ( stdout )
import Stack.Types.Config ( ColorWhen (ColorAuto, ColorNever) )
import System.Console.ANSI ( hSupportsANSIWithoutEmulation )
import System.Environment ( lookupEnv )
defaultColorWhen :: IO ColorWhen
defaultColorWhen :: IO ColorWhen
defaultColorWhen = do
Maybe Bool
supportsANSI <- Handle -> IO (Maybe Bool)
hSupportsANSIWithoutEmulation Handle
stdout
Maybe String
mIsNoColor <- String -> IO (Maybe String)
lookupEnv String
"NO_COLOR"
forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a b. (a -> b) -> a -> b
$ case Maybe String
mIsNoColor of
Just String
_ -> ColorWhen
ColorNever
Maybe String
_ -> case Maybe Bool
supportsANSI of
Just Bool
False -> ColorWhen
ColorNever
Maybe Bool
_ -> ColorWhen
ColorAuto