.\"	$OpenBSD: talk.1,v 1.24 2010/10/21 13:20:51 jmc Exp $
.\"	$NetBSD: talk.1,v 1.3 1994/12/09 02:14:23 jtc Exp $
.\"
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.\"     @(#)talk.1	8.1 (Berkeley) 6/6/93
.\"
.Dd $Mdocdate: October 21 2010 $
.Dt TALK 1
.Os
.Sh NAME
.Nm talk
.Nd talk to another user
.Sh SYNOPSIS
.Nm talk
.Op Fl Hs
.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
The command arguments are as follows:
.Bl -tag -width ttyname
.It Fl H
Don't escape characters with the high bit set.
This may be useful for certain character sets, but could cause erratic
behaviour on some terminals.
.It Fl s
Use smooth scrolling in the
.Nm
window.
The default is to clear the next two rows and jump from the bottom of
the window to the top.
.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
Message from Talk_Daemon@localhost...
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 the login name is the same.
If the machine is not the one to which
the talk request was sent, it is noted on the screen.
Once communication is established,
the two parties may type simultaneously, with their output appearing
in separate windows.
Typing control-L
.Pq Ql ^L
will cause the screen to
be reprinted, while the erase, kill, and word kill characters will
behave normally.
To exit, just type the 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 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 EXIT STATUS
The
.Nm
utility exits 0 on success, and \*(Gt0 if either an error occurred or
.Nm
is
invoked on an unsupported terminal.
.Sh SEE ALSO
.Xr mail 1 ,
.Xr mesg 1 ,
.Xr who 1 ,
.Xr write 1 ,
.Xr talkd 8
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification,
though its presence is optional.
.Pp
The flags
.Op Fl Hs
are extensions to that specification.
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.2 .
.Sh BUGS
The version of
.Nm talk
released with
.Bx 4.3
uses a protocol that
is incompatible with the protocol used in the version released with
.Bx 4.2 .