When first called, talk sends the message
to the user you wish to talk to. At this point, the recipient of the message should reply by typing
It doesn't matter from which machine the recipient replies, as long as his login-name is the same. Once communication is established, the two parties may type simultaneously, with their output appearing in separate windows. Typing control-L '^L' will cause the screen to be reprinted, while your erase, kill, and word kill characters will behave normally. To exit, just type your interrupt character; talk then moves the cursor to the bottom of the screen and restores the terminal to its previous state.
Permission to talk may be denied or granted by use of the mesg (1) command. At the outset talking is allowed. Certain commands, in particular nroff (1) and pr (1) , disallow messages in order to prevent messy output.