.\"	$Source$
.\"	$Author$
.\"	$Header$
.\"
.\" Copyright 1987,1988 by the Massachusetts Institute of Technology
.\" All rights reserved.  The file /usr/include/zephyr/mit-copyright.h
.\" specifies the terms and conditions for redistribution.
.\"
.\"
.TH ZWRITE 1 "October 26, 1989" "MIT Project Athena"
.ds ]W MIT Project Athena
.SH NAME
zwrite \- write to another user via Zephyr
.SH SYNOPSIS
.B zwrite
[
.BI -a
] [
.BI -d
] [
.BI -v
] [
.BI -q
] [
.BI -t
] [
.BI -u
] [
.BI -o
] [
.BI -n
] [
.BI -l
] [
.BI -s
signature ] [
.BI -c
class ] [
.BI -i
instance ] [
.BI -f
arg ] [
.BI user \ ...
] [
.BI -m
.BI message
]
.SH DESCRIPTION
.I Zwrite
sends a message from you to another user through the
.I zephyr(1)
notification service.  The user must have subscribed to messages of
the appropriate class and instance using the
.I zctl(1)
program.
.PP
.I Zwrite
understands the following options.
.TP 12
.B \-a
Causes
.I zwrite
to send the message authenticated, using
.I Kerberos
to perform the authentication.  This is the default.
.TP
.B \-d
Causes
.I zwrite
to send the message unauthenticated.
.TP
.B \-v
Causes
.I zwrite
to print what type of message it is sending, and whether or not it was
successful.
.TP
.B \-q
Forces
.I zwrite
to suppress information about whether or not the message was sent.
.TP
.B \-t
Prevents
.I zwrite
from expanding tabs in the message into appropriate spaces.  Normally
.I zwrite
will expand any tabs it finds into the appropriate number of spaces to
maintain separation based on 8-character tab stops.
.TP
.B \-l
Causes
.I zwrite
to ignore `.' on a line by itself in the input and only end a typed
message when the user types the end-of-file character (usually
control-D).  When the input is not a terminal, this is the default action.
.TP
.B \-u
Sends an urgent message.  This changes the
.I zephyr
instance of the message to ``URGENT''.
.TP
.B \-o
Causes
.I zwrite
to ignore the Zephyr variables 
.I zwrite-class
and
.I zwrite-inst
when picking a default class and instance.
.TP
.B \-n
prevents
.I zwrite
from sending a PING message to verify the recipient is subscribing to
messages.  By default,
.I zwrite
will send a notice to the destination class, instance, and recipient,
with opcode ``PING'' before sending the message.  If the PING is sent,
and the server response indicates there are no recipients subscribed to
your message,
.I zwrite
exits without sending a message.
When the
.B \-m
option is used, no PING is sent.
.TP
.B \-s \fIsignature\fR
sets the signature to be included in the message.  This overrides both
the user's name (as found in the password file) and any
setting of the Zephyr variable 
.IR zwrite-signature .
.I signature
must
be a single argument, hence when using a shell it should be quoted with
double quotes.  A
.I signature
argument of "" leaves the signature in
the message empty.
.TP
.B \-c \fIclass\fR
Allows a user to specify a different class for the message.  This allows
a message to be sent to a large group of people with some degree of
security.  See
.I zephyr(1)
and
.I zephyrd(8)
for a description of how to restrict access to classes.  When this option
is specified, the message is sent to recipient "*" unless an additional
list of recipients is specified.
.br
This argument may not be used in conjunction with the -f option.
.TP
.B \-i \fIinstance\fR
Allows a user to specify a different instance than the default.
When this option is used, the message is sent to recipient "*" unless an
additional list of recipients is specified.  This allows a message to be
sent to a large group of people (e.g. a development group) just by having
the members subscribe to messages of class "MESSAGE", the specified instance,
and recipient "*".
.br
This argument may not be used in conjunction with the -f option.
.TP
.B \-f \fIarg\fR
Allows a user to specify an argument to be interpreted as a filesystem
specification.  The class is set to 
.BR FILSRV .
he instance is set
to
.I arg
as modified:
If
.I arg
contains no colons (`:'), it is assumed to
be a host name, and it is converted into an official host name via 
.I gethostbyname(3).
If
.I arg
contains a colon, the portion preceding the colon is
treated as a host name, and the colon and any trailing characters are
appended to the offical host name returned by
.I gethostbyname.
If the name fails to resolve into an official host name, the instance is
set to
.I arg
unmodified.
.br
This option may not be used in conjunction with the -c or -i option.
.TP
.B \-m
.I Zwrite
sends the remaining arguments on the command line as the message.
.PP
If the
.I \-m
option is not specified, the user is prompted for the message to be
sent.  The message may be terminated by typing ^D or ``.'' on a line
by itself.
.PP
The default class for messages is ``MESSAGE'', and the default instance
is ``PERSONAL''.  These defaults can be overridden by setting the Zephyr
variables
.I zwrite-class
and
.IR zwrite-inst ,
respectively.
.br
Command-line options override the defaults.
.PP
If the class is ``MESSAGE'' and the instance is either ``PERSONAL'' or
``URGENT'', a recipient must be specified.  These comparisons are
case-sensitive.
.PP
Unless the
.B \-s
option is used, the contents of the Zephyr variable
.I zwrite-signature
are used to augment the user's username in the
message.  If
.I zwrite-signature
is not set and the
.B \-s
option is not specified, the user's full name (as specified in the
password file) is used instead.
.SH BUGS
Tab expansion should really be done by the receiver of the message.
.br
The \-u option is provided for compatibility with old versions of
.I zwrite
and is not necessarily useful for sending messages to users who do not
have old subscription files.
.SH SEE ALSO
kerberosintro(1), zctl(1), zephyr(1), zwgc(1), zhm(8), zephyrd(8),
gethostbyname(3)
.br
Project Athena Technical Plan Section E.4.1, `Zephyr Notification
Service'
.SH FILES
/etc/passwd
.br
$HOME/.zephyr.vars
.SH AUTHOR
.PP
.br
Robert S. French (MIT-Project Athena)
.SH RESTRICTIONS
Copyright (c) 1987,1988 by the Massachusetts Institute of Technology.
All Rights Reserved.
.br
.I zephyr(1)
specifies the terms and conditions for redistribution.