How do you clear the console screen in C?

Question

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

Answer 1

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}.

Answer 2

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.

Answer 3

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

Answer 4

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

#include <stdlib.h>

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

Answer 5

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
}

Answer 6

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 ));

Answer 7

#include <conio.h>

and use

clrscr()

Answer 8

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.

Answer 9

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.

Answer 10

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.

Answer 11

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

Answer 12

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..

Answer 13

There's a other way to clear screen. The clrscr way.

#include <conio.h>
int main() {
  clrscr();
  return 0;
}

Answer 14

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");
    }
}