talkuser[@hostname] [tty]
Exchange typed communication with another user who is on the
local machine or on machine hostname. talk might be useful
when you're logged in via modem and need something quickly, making it
inconvenient to telephone or send e-mail. talk splits your
screen into two windows. When connection is established, you type in
the top half while user's typing appears in the bottom half.
Type CTRL-L to redraw the screen and CTRL-D (or interrupt) to exit. If
user is logged in more than once, use tty to specify the
terminal line.