System.Exit
- data ExitCode
- exitWith :: ExitCode -> IO a
- exitFailure :: IO a
- exitSuccess :: IO a
Documentation
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). |
exitWith :: ExitCode -> IO aSource
Computation exitWith codecode
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 nexitFailure is equal to
exitWith (ExitFailure exitfail)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 aSource
The computation exitFailure is equivalent to
exitWith (ExitFailure exitfail),
where exitfail is implementation-dependent.
exitSuccess :: IO aSource
The computation exitSuccess is equivalent to
exitWith ExitSuccess, It terminates the program
successfully.