Clearing output of a terminal program in Linux C

Question

I want to clear the output of a C program produced with printf statements. I want to clear only one line, for example:

[source]

printf("AAAAAAAAAAAAAA\n");
printf("BBBBBBBBBBBBBB\n");
printf("CCCCCCCCCCCCCC\n");
printf("DDDDDDDDDDDDDD\n");

[terminal]

AAAAAAAAAAAAAA
BBBBBBBBBBBBBB
CCCCCCCCCCCCCC
DDDDDDDDDDDDDD

[I hope]

AAAAAAAAAAAAAA
BBBBBBBBBBBBBB
CCCCCCCCCCCCCC

I will "DDDDDDDDDDDDDD" line in write other string. I just want the above A, B, C sentences to left. Only clear D sentences to change the other sentences, unconditionally output D sentences.

How do I do this?

Answer 1

There're several ways to delete the DDDDDDDDDDDDDD

1. Print backspace several times

printf("\b");

2. Print carriage-return and then print something to override the original line

printf("\r");

3. If you are in a newline. You may use terminal commands to move your cursor

such as printf("\033[8;5Hhello"); // Move to (8, 5) and output hello

Other commands:

printf("\033[XA"); // Move up X lines;
printf("\033[XB"); // Move down X lines;
printf("\033[XC"); // Move right X column;
printf("\033[XD"); // Move left X column;
printf("\033[2J"); // Clear screen
...

4. Don't forget ncurses

It is the best ways to control the exact layout and format in a terminal

Answer 2

If you are using X-Term compatibles (Gnome Terminal included), then print the following

printf("\033[2J");

or

cout << "\033[2J";

where \033 is the escape character in ASCII and [2J is the specific action (clear).