Hot to set termcap capability 'bw' flag?

Question

I'm studying termcap library. And I'm trying to do a line editor in the terminal. I have a cursor that can move on the line. Everything works great with one line. But if my line is bigger than terminal width, I can't return my cursor from the second line to the first using le command (move cursor to the left). I need to set bw flag to do this. function tgetflag() only return a value. I think that I need to set this flag using tcsetsttr() but can't find the right flag-macro. How can I set bw flag?

struct termios  stored_settings;
struct termios  new_settings;

tcgetattr(0, &stored_settings);
new_settings = stored_settings;
new_settings.c_lflag &= (~ICANON & ~ECHO);
new_settings.c_cc[VTIME] = 0;
new_settings.c_cc[VMIN] = 1;
tcsetattr(0, TCSANOW, &new_settings);

Answer 1

How can i set bw flag?

auto_left_margin (bw) is one of the terminal capabilities, i. e. it only indicates whether cub1 wraps from column 0 to last column. You cannot change that behavior of the terminal, you can only query it and adapt your program appropriately, e. g. by positioning one line up and to its end with other capabilities.