CODEWITHSUNDEEP
cwindowsconsoleconsole-application
devurs
devurs

Reputation: 883

How do you clear the console screen in C?

Is there a "proper" way to clear the console window in C, besides using system("cls")?

Upvotes: 75

Views: 512891

Answers (13)

user9900365
user9900365

Reputation:

In Windows I have made the mistake of using

system("clear")

but that is actually for Linux

The Windows type is

system("cls")

without #include conio.h

Upvotes: 2

John Knoeller
John Knoeller

Reputation: 34218

There is no C portable way to do this. Although various cursor manipulation libraries like curses are relatively portable. conio.h is portable between OS/2 DOS and Windows, but not to *nix variants.

The entire notion of a "console" is a concept outside of the scope of standard C.

If you are looking for a pure Win32 API solution, There is no single call in the Windows console API to do this. One way is to FillConsoleOutputCharacter of a sufficiently large number of characters. Or WriteConsoleOutput You can use GetConsoleScreenBufferInfo to find out how many characters will be enough.

You can also create an entirely new Console Screen Buffer and make the current one.

Upvotes: 5

MD XF
MD XF

Reputation: 8139

For portability, try this:

#ifdef _WIN32
#include <conio.h>
#else
#include <stdio.h>
#define clrscr() printf("\e[1;1H\e[2J")
#endif

Then simply call clrscr(). On Windows, it will use conio.h's clrscr(), and on Linux, it will use ANSI escape codes.

If you really want to do it "properly", you can eliminate the middlemen (conio, printf, etc.) and do it with just the low-level system tools (prepare for a massive code-dump):

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

void ClearScreen()
{
  HANDLE                     hStdOut;
  CONSOLE_SCREEN_BUFFER_INFO csbi;
  DWORD                      count;
  DWORD                      cellCount;
  COORD                      homeCoords = { 0, 0 };

  hStdOut = GetStdHandle( STD_OUTPUT_HANDLE );
  if (hStdOut == INVALID_HANDLE_VALUE) return;

  /* Get the number of cells in the current buffer */
  if (!GetConsoleScreenBufferInfo( hStdOut, &csbi )) return;
  cellCount = csbi.dwSize.X *csbi.dwSize.Y;

  /* Fill the entire buffer with spaces */
  if (!FillConsoleOutputCharacter(
    hStdOut,
    (TCHAR) ' ',
    cellCount,
    homeCoords,
    &count
    )) return;

  /* Fill the entire buffer with the current colors and attributes */
  if (!FillConsoleOutputAttribute(
    hStdOut,
    csbi.wAttributes,
    cellCount,
    homeCoords,
    &count
    )) return;

  /* Move the cursor home */
  SetConsoleCursorPosition( hStdOut, homeCoords );
}

#else // !_WIN32
#include <unistd.h>
#include <term.h>

void ClearScreen()
{
  if (!cur_term)
  {
     int result;
     setupterm( NULL, STDOUT_FILENO, &result );
     if (result <= 0) return;
  }

   putp( tigetstr( "clear" ) );
}
#endif

Upvotes: 29

Avinash Katiyar
Avinash Katiyar

Reputation: 591

printf("\e[1;1H\e[2J");

This function will work on ANSI terminals, demands POSIX. I assume there is a version that might also work on window's console, since it also supports ANSI escape sequences.

#include <unistd.h>

void clearScreen()
{
  const char *CLEAR_SCREEN_ANSI = "\e[1;1H\e[2J";
  write(STDOUT_FILENO, CLEAR_SCREEN_ANSI, 12);
}

There are some other alternatives, some of which don't move the cursor to {1,1}.

Upvotes: 48

Tom
Tom

Reputation: 45174

Well, C doesn't understand the concept of screen. So any code would fail to be portable. Maybe take a look at conio.h or curses, according to your needs?

Portability is an issue, no matter what library is used.

Upvotes: 32

nbro
nbro

Reputation: 15878

Using macros you can check if you're on Windows, Linux, Mac or Unix, and call the respective function depending on the current platform. Something as follows:

void clear(){
    #if defined(__linux__) || defined(__unix__) || defined(__APPLE__)
        system("clear");
    #endif

    #if defined(_WIN32) || defined(_WIN64)
        system("cls");
    #endif
}

Upvotes: 15

Jamesits
Jamesits

Reputation: 642

A workaround tested on Windows(cmd.exe), Linux(Bash and zsh) and OS X(zsh):

#include <stdlib.h>

void clrscr()
{
    system("@cls||clear");
}

Upvotes: 21

JD3
JD3

Reputation: 410

This should work. Then just call cls(); whenever you want to clear the screen.

(using the method suggested before.)

#include <stdio.h>
void cls()
{
    int x;
    for ( x = 0; x < 10; x++ ) 
    {
        printf("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
    }
}

Upvotes: -6

Vivek Sharma
Vivek Sharma

Reputation: 3814

#include <conio.h>

and use 

clrscr()

Upvotes: 9

Feridun
Feridun

Reputation: 145

just type clrscr(); function in void main().

as example:

void main()
{
clrscr();
printf("Hello m fresher in programming c.");
getch();
}

clrscr();

function easy to clear screen.

Upvotes: 3

gfe
gfe

Reputation: 774

Windows:

system("cls");

Unix:

system("clear");

You could instead, insert newline chars until everything gets scrolled, take a look here.

With that, you achieve portability easily.

Upvotes: 5

Mark Wilkins
Mark Wilkins

Reputation: 41262

Since you mention cls, it sounds like you are referring to windows. If so, then this KB item has the code that will do it. I just tried it, and it worked when I called it with the following code:

cls( GetStdHandle( STD_OUTPUT_HANDLE ));

Upvotes: 9

Jack
Jack

Reputation: 133669

The proper way to do it is by using tput or terminfo functions to obtain terminal properties and then insert newlines according to the dimensions..

Upvotes: 0

Related Questions