Safe Haskell	Safe-Inferred
Language	Haskell2010

System.Exit

Description

Synopsis

data ExitCode
- = ExitSuccess
- | ExitFailure Int
exitWith :: ExitCode -> IO a
exitFailure :: IO a
exitSuccess :: IO a

Documentation

data ExitCode #

Defines the exit codes that a program can return.

Constructors

ExitSuccess	indicates successful termination
ExitFailure Int	indicates program failure with an exit code. The exact interpretation of the code is operating-system dependent. In particular, some values may be prohibited (e.g. 0 on a POSIX-compliant system).

Instances

Instances details

Eq ExitCode #
Instance details Defined in System.Exit Methods (==) :: ExitCode -> ExitCode -> Bool # (/=) :: ExitCode -> ExitCode -> Bool #
Ord ExitCode #
Instance details Defined in System.Exit Methods compare :: ExitCode -> ExitCode -> Ordering # (<) :: ExitCode -> ExitCode -> Bool # (<=) :: ExitCode -> ExitCode -> Bool # (>=) :: ExitCode -> ExitCode -> Bool # (>) :: ExitCode -> ExitCode -> Bool # max :: ExitCode -> ExitCode -> ExitCode # min :: ExitCode -> ExitCode -> ExitCode #
Read ExitCode #
Instance details Defined in System.Exit Methods readsPrec :: Int -> ReadS ExitCode # readList :: ReadS [ExitCode] #
Show ExitCode #
Instance details Defined in System.Exit Methods showsPrec :: Int -> ExitCode -> ShowS # show :: ExitCode -> String # showList :: [ExitCode] -> ShowS #

exitWith :: ExitCode -> IO a #

Computation exitWith code terminates the program, returning code to the program’s caller. The caller may interpret the return code as it wishes, but the program should return ExitSuccess to mean normal completion, and ExitFailure n to mean that the program encountered a problem from which it could not recover. The value exitFailure is equal to exitWith (ExitFailure exitfail), where exitfail is implementation-dependent. exitWith bypasses the error handling in the I/O monad and cannot be intercepted by catch from the Prelude.

exitFailure :: IO a #

The computation exitFailure is equivalent to exitWith (ExitFailure exitfail), where exitfail is implementation-dependent.

exitSuccess :: IO a #

The computation exitSuccess is equivalent to exitWith ExitSuccess. It terminates the program successfully.