Question

Following is the code snippet.

int main()
{
int i =0;
    while (i++ < 5)
    {
        // Do some heavy processing
        printf("i = %d\n", i);
        sleep(1);
    }
}

The heavy processing part is doing its part every 1 second.
I want to display ‘i’ after 1 s as well but its displaying the entire output after its done. I know using a while is not a very elegant way to do this, but it seemed easier. Which is the optimal way of achieving this?

I am running the code in unix, gcc complier

Answer 1

You need to flush stdout; you can use fflush(3) to do so:

fflush(stdout);

You could also disable buffering entirely on stdout:

setbuf(stdout, NULL);