| TALK(1) | General Commands Manual | TALK(1) | 
talk —
| talk | person [ttyname] | 
talk is a visual communication program which copies
  lines from your terminal to that of another user.
Options available:
user@host’.ttyXX’.When first called, talk sends the
  message
Message from TalkDaemon@his_machine... talk: connection requested by your_name@your_machine. talk: respond with: talk your_name@your_machine
to the user you wish to talk to. At this point, the recipient of the message should reply by typing
talk
   your_name@your_machineIt 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.
TALKHOST environment variable is set, its value
  is used as the hostname the talk
  packets appear to be originating from. This is useful if you wish to talk to
  someone on another machine and your internal hostname does not resolve to the
  address of your external interface as seen from the other machine.
talk command appeared in
  4.2BSD.
talk released with
  4.3BSD uses a protocol that is incompatible with the
  protocol used in the version released with 4.2BSD.
| January 7, 2007 | NetBSD 9.4 |