haskell2010- Compatibility with Haskell 2010




getArgs :: IO [String]Source

Computation getArgs returns a list of the program's command line arguments (not including the program name).

getProgName :: IO StringSource

Computation getProgName returns the name of the program as it was invoked.

However, this is hard-to-impossible to implement on some non-Unix OSes, so instead, for maximum portability, we just return the leafname of the program as invoked. Even then there are some differences between platforms: on Windows, for example, a program invoked as foo is probably really FOO.EXE, and that is what getProgName will return.

getEnv :: String -> IO StringSource

Computation getEnv var returns the value of the environment variable var.

This computation may fail with:

  • System.IO.Error.isDoesNotExistError if the environment variable does not exist.