@[inline]

def System.Environment.lookupEnv (name : String) : IO (Option String)

Look up an environment variable by name.

$$\text{lookupEnv} : \text{String} \to \text{IO}\ (\text{Option}\ \text{String})$$

Returns some value if the variable is set, none otherwise.

Equations

• System.Environment.lookupEnv name = liftM (IO.getEnv name)

def System.Environment.getEnv (name : String) : IO String

Get an environment variable, returning empty string if not set.

$$\text{getEnv} : \text{String} \to \text{IO}\ \text{String}$$

Total accessor: returns "" when the variable is absent.

Equations

• System.Environment.getEnv name = do let __do_lift ← System.Environment.lookupEnv name match __do_lift with | some v => pure v | none => pure ""

def System.Environment.getHome : IO (Option String)

Get the value of the HOME environment variable.

$$\text{getHome} : \text{IO}\ (\text{Option}\ \text{String})$$

Equations

• System.Environment.getHome = System.Environment.lookupEnv "HOME"

def System.Environment.getPath : IO (Option String)

Get the value of the PATH environment variable.

$$\text{getPath} : \text{IO}\ (\text{Option}\ \text{String})$$

Equations

• System.Environment.getPath = System.Environment.lookupEnv "PATH"