If you wish to talk to someone on your own machine, then
username is just the person's login name. If you wish to
talk to a user on another host, then username is one of the
following forms :
host!user
host.user
host:user
user@host
though user@host is perhaps preferred.
If you want to talk to a user who is logged in more than once, the ttyname argument may be used to indicate the appropriate terminal name.
When first called, talk sends the message:
Message from TalkDaemon@his_machineattime... 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:
example% talk your_name@your_machine
It does not matter from which machine the recipient replies, as long as their login name is the same. Once communication is established, the two parties may type simultaneously, with their output appearing in separate windows. Typing CTRL-L redraws the screen, while your erase, kill, and word kill characters will work in talk as normal. To exit, just type your interrupt character; talk then moves the cursor to the bottom of the screen and restores the terminal.
Permission to talk may be denied or granted by use of the mesg command. At the outset talking is allowed. Certain commands, in particular nroff(1) and pr(1V) disallow messages in order to prevent messy output.