How do I clear the terminal screen in Haskell?

问题

How can I clear a terminal screen after my user has selected an option from my application's menu?

回答1:

:! run the shell command
:! cls under windows
:! clear under linux and OS X

回答2:

This is what you may be looking for:

ansi-terminal: Simple ANSI terminal support, with Windows compatibility

You can find it in Hackage and install using cabal install ansi-terminal. It specifically has functions for clearing the screen, displaying colors, moving the cursor, etc.

Using it to clear the screen is easy: (this is with GHCI)

import System.Console.ANSI

clearScreen

回答3:

On a terminal that understands ANSI escape sequences (I believe every term in Unix/Linux systems) you can do it simply with:

clear = putStr "\ESC[2J"

The 2 clears the entire screen. You can use 0 or 1 respectively if you want to clear from the cursor to end of screen or from cursor to the beginning of the screen.

However I don't think this works in the Windows shell.

回答4:

On Unix systems you can do System.system "clear" which just invokes the command-line utility clear. For a solution that does not depend on external tools, you'd need a library that abstracts over different terminal-types like for example ansi-terminal.

回答5:

Just press Ctrl+L (works on Windows)

回答6:

A quick way on Windows would be to

import System.Process

clear :: IO ()
clear = system "cls"

回答7:

On Windows, use Ctrl + L for Haskell command prompt terminal. And, for GUI use Ctrl + S.

回答8:

Under Linux (Ubuntu at least), that's the code I use for clearing the terminal:

import qualified System.Process as SP

clearScreen :: IO ()
clearScreen = do
  _ <- SP.system "reset"
  return ()

来源：https://stackoverflow.com/questions/2472391/how-do-i-clear-the-terminal-screen-in-haskell