CODEWITHSUNDEEP
c++cstdout
u17
u17

Reputation: 2824

Undo a newline (\n) printed to command line

printf("Error %d\n", 1);
printf("\nStatus: %d%%", 50);

prints 

Error 1

Status: 50%

In this set up, is there any chance to insert Error 2\n between Error 1\n and \nStatus: 50%. I understand that \r and \b can be used to change printed text in the same line (e.g., if there is a single \n between Error 1 and Status: 50%), but can I change text in a previous line?

Thanks!

Upvotes: 11

Views: 3114

Answers (3)

Yakov Galka
Yakov Galka

Reputation: 72469

What @Ryan said.

Explanation why: stdout is some abstract stream that doesn't have to be the terminal. It may be a file, a pipe, a socket, a printer, a text to speech device or whatever. In many cases there is no sense to what you asked to do. Hence you need some library that works with the terminal specifically.

Upvotes: 7

Christoph Haefner
Christoph Haefner

Reputation: 1103

You could use ANSI Escapesequences to move your "cursor" one line up:

void cursorOnLineUp(void) { printf("\033[1A"); }

Or set it to a specific position:

void setCursor(int column, int row) { printf("\033[%d;%dH", row, column) }

Haven't tried it for C++, but succesfully used it for a simple game in ANSI-C!

Upvotes: 2

Ryan Li
Ryan Li

Reputation: 9330

Sorry, you cannot.

But you may issue system calls to clear the whole screen instead, like system("clear") (OS-dependent).

Or use ncurses just as Kos mentioned in the comment.

Upvotes: 3

Related Questions