c++ Print on same line

Question

I am using a chrono to get the time elapsed during a loop. I would like to display this time every loop run.

I can do this:

for(int i = 0;i<3;i++)
{
    sleep(2 secs);
    time= get_time();
    cout<<"time is : "<<time;
}

But I have the output:

time is : 2 time is : 4 time is : 6

I could add an endl to have it in column but that is not what I want. My loop is about million times, so I don't really want to print a million lines.

I would just like to print like:

time is : 2

and then refresh it to

time is : 4

and so on. Is there a way to do this?

Experiment with the carriage-return `'\r'` character. – Some programmer dude Apr 10 '17 at 18:29 — Some programmer dude, Apr 10 '17 at 18:29
Working with \r and flush ! thanks – Minamoto Apr 10 '17 at 18:35 — Minamoto, Apr 10 '17 at 18:35

score 1 · Answer 1 · answered Apr 10 '17 at 18:37

1

You can use endl with clrscr() .

answered Apr 10 '17 at 18:37

Bertram Gilfoyle

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thanks but i didnt want to erase my previous output on the console before this loop – Minamoto Apr 10 '17 at 18:39
This is not a portable solution. OP did not specify a compiler or platform. – François Andrieux Apr 10 '17 at 18:42

score 1 · Answer 2 · edited May 23 '17 at 11:46

printing to terminals is very easy, but it can be extremely hard at the same time. At its core, a terminal is simply a file, that you can use to write or read on. Performing tasks such as changing cursor's position is in fact system-specific and your code will have to be platform dependent.

But don't panic! People have done it before and even wrote libraries to do it. I think NCurses will do the job. https://www.gnu.org/software/ncurses/ncurses.html

I advice you to refer to this thread to see some issue related to your question: How to clear a specific line with NCurses?

I have never used ncurses my self, so I wish you best of luck!

Enjoy programming!

c++ Print on same line

2 Answers2