Function term_size::dimensions

pub fn dimensions() -> Option<(usize, usize)>

Query the current processes’s output (stdout), input (stdin), and error (stderr) in that order, in the attempt to dtermine terminal width. If one of those streams is actually a tty, this function returns its width and height as a number of characters.

If all of the streams are not ttys or return any errors this function will return None.