Function forkpty 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn forkpty(
    pm: *mut c_int,
    name: *mut c_char,
    tio: *const termios,
    ws: *const winsize,
) -> c_int

See https://www.man7.org/linux/man-pages/man3/openpty.3.html.