Can I use ansi escape sequence to clear the screen?

[zsdz]

I have the simple prog:

TShutdownMode CKernel::Run (void)
{
	m_Screen.Write("AAA\n",3);
	m_Screen.Write("AAA\n",3);
	m_Screen.Write("AAA\n",3);
	m_Screen.Write("AAA\n",3);
	m_Screen.Write("AAA\n",3);

	char *a="\033[2J\033[H";
	//printf("\033[2J\033[H");
	m_Screen.Write(a,sizeof(a));

	return ShutdownHalt;
}

effort(on rpi4):
![a](https://github.com/user-attachments/assets/a257f30c-6ff9-4178-83b1-102546446670)


the cursor have been move to left top,but the letters stay the same(screen have not been cleared)

so circle not support use ansi escape sequence to clear the screen?

I know `CScreenDevice` have method `Initialize()` to clear the screen.but I only want to clear the screen,not Initialize it again.I doubt if this method is too heavy

Is there a convenient method to clear the screen in circle?Thanks!

[rsta2]

The sequence ESC [J clears the screen from the cursor position to the end of the screen. You should send "cursor home" before. All supported escape sequences can be found in doc/screen.txt.

[zsdz]

It works,Thanks!I should read the docs more and more careful

[smuehlst]

I think there's a bug in the program:

        char *a="\033[2J\033[H";
	//printf("\033[2J\033[H");
	m_Screen.Write(a,sizeof(a));

sizeof(a) evaluates to the size of the pointer a, not to the size of the character array that it points to.

What you probably want is this:

   const char *a="\033[2J\033[H";
   m_Screen.Write(a, strlen(a));

or alternatively

   const char a[]="\033[2J\033[H";
   m_Screen.Write(a, sizeof(a) - 1); // exclude terminating 0-character at end of string

[zsdz]

Thanks.I use the escape sequence as doc/screen.txt said and cleared the screen:

char *a="\x1b[H\x1b[J";
m_Screen.Write(a,strlen(a));