lookupEnv : String -> Maybe String with EnvLook up an environment variable; Nothing if it is not set.
importPour l'utiliser :
import System.EnvSystem.Env — environment, working directory, process control
Synopsis
getEnv : String -> Result String String with EnvGet an environment variable, or an error message naming the missing var.
currentDir : Path with EnvThe current working directory.
homeDir : Maybe Path with EnvThe user's home directory, if known.
time : Int with ClockThe wall-clock time in milliseconds (only differences are meaningful).
sleep : Nat -> () with ClockPause for the given number of milliseconds (a no-op in the browser).
exit : Int -> a with IOEnd the program with the given exit code. Never returns.