.\"	$NetBSD: talk.1,v 1.9 2007/01/08 17:10:59 christos Exp $
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.\"     @(#)talk.1	8.1 (Berkeley) 6/6/93
.\"
.Dd January 7, 2007
.Dt TALK 1
.Os
.Sh NAME
.Nm talk
.Nd talk to another user
.Sh SYNOPSIS
.Nm
.Ar person
.Op Ar ttyname
.Sh DESCRIPTION
.Nm
is a visual communication program which copies lines from your
terminal to that of another user.
.Pp
Options available:
.Bl -tag -width ttyname
.It Ar person
If you wish to talk to someone on your own machine, then
.Ar person
is just the person's login name.
If you wish to talk to a user on another host, then
.Ar person
is of the form
.Ql user@host .
.It Ar ttyname
If you wish to talk to a user who is logged in more than once, the
.Ar ttyname
argument may be used to indicate the appropriate terminal
name, where
.Ar ttyname
is of the form
.Ql ttyXX .
.El
.Pp
When first called,
.Nm
sends the message
.Bd -literal -offset indent -compact
Message from TalkDaemon@his_machine...
talk: connection requested by your_name@your_machine.
talk: respond with: talk your_name@your_machine
.Ed
.Pp
to the user you wish to talk to.
At this point, the recipient
of the message should reply by typing
.Pp
.Dl talk \ your_name@your_machine
.Pp
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
.Ql ^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;
.Nm
then moves the cursor to the bottom of the screen and restores the
terminal to its previous state.
.Pp
Permission to talk may be denied or granted by use of the
.Xr mesg 1
command.
At the outset talking is allowed.
Certain commands, in
particular
.Xr nroff 1
and
.Xr pr 1 ,
disallow messages in order to
prevent messy output.
.Sh ENVIRONMENT
If the
.Ev TALKHOST
environment variable is set, its value is used as the
.Ar hostname
the
.Nm
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.
.Sh FILES
.Bl -tag -width /var/run/utmp -compact
.It Pa /etc/hosts
to find the recipient's machine
.It Pa /var/run/utmp
to find the recipient's tty
.El
.Sh SEE ALSO
.Xr mail 1 ,
.Xr mesg 1 ,
.Xr who 1 ,
.Xr write 1
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.2 .
.Sh BUGS
The version of
.Nm
released with
.Bx 4.3
uses a protocol that
is incompatible with the protocol used in the version released with
.Bx 4.2 .