Terminal control/Clear the screen

Terminal control/Clear the screen
You are encouraged to solve this task according to the task description, using any language you may know.

Clear the terminal window.

Ada

For systems with ANSI terminal handling:

<lang Ada>with Ada.Text_IO; procedure CLS is begin

  Ada.Text_IO.Put(ASCII.ESC & "[2J");

end CLS;</lang>

AutoHotkey

Reference: http://www.autohotkey.com/forum/topic76532.html <lang AHK>RunWait %comspec% /c cls</lang>

AWK

<lang awk>system("clear")</lang>

BASIC

Works with: QBasic

Works with: Locomotive Basic

Works with: ZX Spectrum Basic

Works with: BBC BASIC

<lang qbasic>CLS</lang>

Batch File

<lang command>CLS</lang>

Blast

<lang blast>clear</lang>

C

The C version of the Minesweeper game uses curses.

If perhaps clear screen isn't used, call the function cls to do the trick.

<lang C>void cls(void) {

 int printf(char*,...);
 printf("%c[2J",27);

}</lang>

C#

<lang csharp>System.Console.Clear();</lang>

Euphoria

<lang Euphoria>clear_screen()</lang>

Forth

<lang forth>page</lang>

Go

<lang go>package main

import (

   "os"
   "os/exec"

)

func main() {

   c := exec.Command("clear")
   c.Stdout = os.Stdout
   c.Run()

}</lang>

GUISS

This will only work if the terminal is sitting at a prompt. <lang guiss>Window:Terminal,Type:clear[enter]</lang>

GW-BASIC

<lang qbasic>10 CLS</lang>

Icon and Unicon

Example works for both Icon and Unicon. Determine which system command to call by querying &features at run time. Alternately, the related preprocessor symbols can be used to select the operating system. <lang Icon>procedure main ()

 if &features == "MS Windows" then system("cls")  # Windows
 else if &features == "UNIX" then system("clear") # Unix

end</lang>

J

Note: this is specific the java+gdi based J ide. <lang j>smwrite_jijs_ </lang>

Logo

<lang logo>cleartext</lang> There is a separate command to reset the turtle graphics window. <lang logo>clearscreen cs  ; abbreviation for clearscreen clean  ; like cs, but doesn't reset turtle position</lang>

Lua

<lang lua>os.execute( "clear" )</lang> will not work because "clear" is not a command

Pascal

<lang Pascal>clrscr;</lang>

Perl

Assuming some ANSI terminal, easiest way is call your system's clear command: <lang perl>system('clear')</lang>

If it's needed often: <lang perl>$clear = `clear`; # clear simply prints some escape sequence, cache it

1. ... later:

print $clear;</lang>

PicoLisp

<lang PicoLisp>(call 'clear)</lang>

PowerShell

<lang powershell>Clear-Host</lang>

ProDOS

<lang ProDOS>clearscurrentscreentext</lang>

PureBasic

Clears the whole console content using the current background color. <lang PureBasic>ClearConsole()</lang>

Python

Works with: Python version 2.6

Works with: Ubuntu version 10.10

To clear the screen on windows, replace 'clear' with 'cls'

<lang python> import os os.system('clear') </lang>

or similar to C example

<lang python> print "%c[2J" % (27) </lang>

Retro

<lang Retro>clear</lang>

REXX

The REXX programming language does not include a facility to clear the screen. However, it is possile to execute an external system command to achieve this task:

'clear'

There are also various workarounds which are platform specific:

regina

The regina interpreter supports the rexxcurses plugin, which provides the facility to clear the screen:

Seed7

The function clear is portable and clears the console window. Clear is based on terminfo respectively the Windows console API. A portable function to clear cannot rely on shell respectively cmd.exe commands, because Windows uses CLS and Unix shells use CLEAR, to clear a screen. ANSI terminal escape sequences are also not 100% portable, since not all terminals accept them.

<lang seed7>$ include "seed7_05.s7i";

 include "console.s7i";

const proc: main is func

 local
   var text: console is STD_NULL;
 begin
   console := open(CONSOLE);
   clear(console);
   # Terminal windows often restore the previous
   # content, when a program is terminated. Therefore
   # the program waits until Return/Enter is pressed.
   readln;
 end func;</lang>

Tcl

This only works on systems with ANSI terminal handling, i.e., Unix platforms. <lang tcl>puts -nonewline "\033\[2J" flush stdout</lang>

UNIX Shell

The clear command can be used to clear the terminal screen:

Works with: Bourne Shell

<lang bash>clear

1. Alternative method using tput

tput clear</lang>