Function one_line 

pub(crate) fn one_line(text: &str) -> String

Words from elsewhere (mail, invitations, contacts, file names) on one line, as they are shown: a line break or a tab becomes a space, and the other control characters go (a terminal’s escape sequences, the marks that turn text right to left), so that they can neither break a line of what is shown, nor pass for it, nor drive the terminal.