Clearing output of a terminal program Linux C/C++

Question

I'm interested in clearing the output of a C program produced with printf statements, multiple lines long.

My initial guess was to use

 printf("output1
");
 printf("output2
");
 rewind(stdout);
 printf("output3
");
 printf("output4
");

but this produces

 output1
 output2
 output3
 output4

I was hoping it would produce

 output3
 output4

Does anyone know how to get the latter result?

Answer 1

You can have the desired result both for terminal and pipes if you remember to remove the control characters as well. This is hardcoded for two lines.

#include <stdio.h>

int
main ()
{
    fputs("output1
",stdout);
    fputs("output2
",stdout);
    fputs("33[A33[2K33[A33[2K",stdout);
    rewind(stdout);
    ftruncate(1,0); /* you probably want this as well */
    fputs("output3
",stdout);
    fputs("output4
",stdout);
    return 0;
}