V8/usr/man/man1/write.1

.TH WRITE 1 
.SH NAME
write  \-  write to other users
.SH SYNOPSIS
.B write
person ...
.SH DESCRIPTION
.I Write
copies lines from your terminal to terminals of other 
.I persons
designated either by login name or
(to circumvent occasional ambiguities) by terminal name
as given by
.IR who (1).
It announces to each
.I  person 
your login name, your terminal,
and the other
.I persons.
To respond, each recipient should execute a corresponding
.I write
to the
.I  persons 
he wants to talk to.
.PP
When you are writing to more than one person, your
messages are identified to the recipients.
Writing ends upon end of file or interrupt,
and the message `EOF' is sent to the others.
.PP
.I Write
recognizes certain commands during a conversation:
.TP 10
.BI ! cmd
Execute a shell on the string
.I cmd
and then return to
.IR write .
.TP 10
.BI :a " person"
Add
.I person
to the list of people to whom you are talking,
and send an appropriate announcement to all parties.
They must do
.B :a
for themselves if they want to include the new person.
.TP 10
.BI :d " person"
Drop
.I person
from your list and make appropriate announcements.
.TP 10
.B :l
Print a list of people to whom you are talking.
.PP
The following protocol is suggested for using
.IR write :
when you first write to another user, wait for him to
write back before starting to send.
Each party should end each message with a distinctive
signal\(em\fB(o)\fR
for `over' is conventional\(emthat the other may reply.
.B (oo)
for `over and out' is suggested when conversation
is about to be terminated.
.PP
Permission to write may be denied or granted by 
.IR mesg (1).
Normally writing is allowed.
Certain commands, in particular
.I nroff
and
.IR  pr (1)
disallow
messages in order to prevent messy output.
.SH FILES
/etc/utmp	to find user
.br
/bin/sh		to execute `!'
.SH "SEE ALSO"
mesg(1), who(1), mail(1)
.SH BUGS
Messages ought to be identified when the recipient is receiving from
more than one writer, rather than when the writer is sending
to more than one recipient,
but that requires cooperating processes and isn't
worth the effort.