.\"	$OpenBSD: write.1,v 1.19 2016/02/05 21:03:51 schwarze Exp $
.\"
.\" Copyright (c) 1989, 1993
.\"	The Regents of the University of California.  All rights reserved.
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.\" This code is derived from software contributed to Berkeley by
.\" Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
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.\"     from: @(#)write.1	8.1 (Berkeley) 6/6/93
.\"
.Dd $Mdocdate: February 5 2016 $
.Dt WRITE 1
.Os
.Sh NAME
.Nm write
.Nd send a message to another user
.Sh SYNOPSIS
.Nm write
.Ar user
.Op Ar ttyname
.Sh DESCRIPTION
.Nm
allows you to communicate with other users, by copying lines from
your terminal to theirs.
.Pp
When you run the
.Nm
command, the user you are writing to gets a message of the form:
.Pp
.Dl Message from yourname@yourhost on yourtty at hh:mm ...
.Pp
Any further lines you enter will be copied to the specified user's
terminal.
If the other user wants to reply, they must run
.Nm
as well.
.Pp
When you are done, type an end-of-file or interrupt character.
The other user will see the message
.Dq EOF
indicating that the conversation is over.
.Pp
You can prevent people (other than the superuser) from writing to you
with the
.Xr mesg 1
command.
Some commands, such as
.Xr pr 1 ,
disallow writing automatically, so that output isn't overwritten.
.Pp
If the user you want to write to is logged in on more than one terminal,
you can specify which terminal to write to by specifying the terminal
name as the second operand to the
.Nm
command.
Alternatively, you can let
.Nm
select one of the terminals \- it will pick the one with the shortest
idle time.
This is so that if the user is logged in at work and also dialed up from
home, the message will go to the right place.
.Pp
The traditional protocol for writing to someone is that the string
.Dq \-o ,
either at the end of a line or on a line by itself, means that it's the
other person's turn to talk.
The string
.Dq oo
means that the person believes the conversation to be
over.
.Sh ASYNCHRONOUS EVENTS
.Bl -tag -width SIGINTXXX
.It Dv SIGINT
Terminate
.Nm
and exit with a zero status.
.El
.Sh EXIT STATUS
The
.Nm
utility exits with one of the following values:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It 0
Normal behavior.
.It >0
The specified user is either not logged in or not accepting messages.
.El
.Sh SEE ALSO
.Xr mesg 1 ,
.Xr talk 1 ,
.Xr who 1
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification, except that in this implementation the sender's
locale is intentionally ignored in order to avoid sending characters
that the receiving terminal may be unable to display, or even bytes
that might break the receiving terminal's state.
Non-ASCII characters are written as
.Sq \&? .
.Sh HISTORY
A
.Nm
command appeared in
.At v2 .
.Sh BUGS
The
.Dq EOF
message seen when the other
.Nm
terminates is indistinguishable from that party simply typing
.Dq EOF
to make you believe that any future messages did not come from them.
Especially messages such as:
.Pp
.Dl "[1]    Done                   rm -rf *"