.TH MSGS 1
.SH NAME
Msgs, mail2fs, M, Mg, mspool, mailplumb, msgs, Arch, Spam, Reply, Send, Post, Delmesg, Save \- file based mail reader
.SH SYNOPSIS
.B mail2fs
[
.B -acDnor
]
[
.B -d
.I mdir
]
[
.I mbox
]
.PP
.B msgs
[
.B -aD
]
[
.B -s
.I runes
]
[
.I mdir
]
[
.I monthdir
]
.PP
.B M
.I cmd
[
.I dir
.B ...
]
.PP
.B Mg
[
.B -h
]
[
.I regexp
]
.PP
.B mspool
.PP
.B mailplumb
[
.B -dho
]
[
.I mdir
]
.PP
.B Msgs
[
.B -a
]
[
.I mdir
[
.I monthdir
]
]
.PP
.B Arch
[
.I file
.B ...
]
.PP
.B Spam
[
.I file
.B ...
]
.PP
.B Reply
.PP
.B Send
.PP
.B Delmesg
[
.I file
.B ...
]
.PP
.B Post
.PP
.B Save
.I file
.PP
.B mlist
.SH DESCRIPTION
These programs cooperate to provide mail reading and delivering facilities
by using files from a shared file server. Msgs are stored in a convenient way
to read or process them just by browsing files, using a Plan B mail box format.
.SS Mail box format
In Plan B, msgs for users are parsed and decoded first,
and then stored in a file hierarchy where these and other
tools can be used to process them.  A mailbox is a directory, usually under
.BR /mail/box/$user/ ,
that contains one directory per month (e.g.,
.BR 200603/
for msgs processed on March 2006). 
In these diretories there is one directory per message. The
convention is that (message directory) names starting with
.L a.
correspond to archived messages not to be usually shown to the user. Names starting with
.L s.
correspond to messages that seem to be spam (not usually shown either). Names
starting with
.L d.
correspond to deleted messages not yet removed from the file system.
Any other rune can be used instead of
.L a ,
.L s
or
.L d
as a convenience (the meaning would be up to the user). But for this optional
prefix, messages use a
serial message number as their directory name.
.PP
The directory for a message contains at least two files:
.B text
and
.BR raw .
The
.B text
file has the mail headers and body already processed for reading, and
.B raw
has the original mail headers without any processing, including the
UNIX header line (for debugging and also for obtaining message ids when
replying to msgs).
As an option,
.B raw
may contain the entire original mail without processing and not just
the headers.
Any attachment in the mail is kept stored in a separate file (possibly
with the file name indicated in the MIME headers) ready to be used,
that is, decoded. When the attachment is a mail, the message is
stored in a subdirectory following the same conventions stated above.
For msgs with attachments, the
.B text
file contains additional text indicating the relative path names (from the
mail's directory) that can be used to open the attachments. This is
convenient to
.IR plumb (1)
them while reading.
.PP
Because all these files have been already processed for reading,
the usual file handling tools can be used to read, edit, copy, or
remove them.
.PP
The mailbox used by default is
.BR /mail/box/$user/msgs ,
and corresponds to the inbox.
.PP
A Plan B mail box also contains two files:
.B seq
and
.BR digest .
Messages are given sequence numbers as added to the mail box. The
file
.B seq
contains the sequence number for the last message (or zero) and is
.B DMEXCL
to provide locking for multiple programs using the mail box.
The file
.B digest
contains digests for msgs added to the mailbox using
.I mail2fs
(and not for those added by hand using file tools).
When a message has a digest that was already seen in the past
the
message is silently discarded as a dupplicate.
.PP
Programs described below are parsimonious enough in the format
of the mail box so that they will work even if messages are edited by
hand, other files are created, or some of them are removed.
.PP
Virtual mail folders may be created by storing text files with
mail lists that contain a mail description per line starting with
the path for each mail. Copying the text shown for some messages
in a mail listing into another text file would ``save'' such messages
into that file. The program
.I mlist
writes to standard output a clean listing for messages with paths
found in the standard input.
.PP
A file (a virtual folder) named like a
per-month directory with
.L .l
or
.L .la
appended is considered a cache of the listing for that directory. But only if the directory has
not been modified after the file. For example,
a text file named
.B 200909.l
(containing a mail listing in the format shown by
.I msgs )
will be used to list msgs on September 2009, instead of the
.B 200909
directory and its contents. This file will be ignored for mailbox listings if the
directory is modified after the file and the cache is, therefore, out of date.
A file named
.B 200909.la
behaves like before, but is known to contain only archived msgs. It is, therefore,
ignored when listing non-archived msgs. The
.I msgs
program automatically renames
.L .l
files to
.L la
when the file lists only archived mail.
.SS Reading mail
Mail is converted from a Plan 9 mailbox into a Plan B mailbox using
.IR mail2fs .
This program may be run using
.IR cron (8)
or directly from the
.B pipeto
file described in
.IR mail (1).
It uses
.BR upas/fs ,
described in
.IR upasfs (1),
to parse the Plan 9 mail box.
.PP
By default
.B /mail/box/$user/mbox
is the source (Plan 9) mail box. Messages found on it are moved into
(in Plan B mailbox format).
The argument
.I mbox
specifies another mail source, to be used instead of the default.
Option
.B -d
changes the destination to
.IR mdir .
.PP
Messages are deleted from the Plan 9 mailbox unless flag
.B -n
is given. The Plan B mailbox is created if it does not exist only
if flag
.B -c
is given.
.PP
Flag
.B -a
makes
.I mail2fs
add new messages as archived to the Plan B mailbox. This is
useful to add messages to a mailbox for further reference, 
not for listing when asking the mail index for the mailbox. For
example, to archive outgoing mail in the default mail box.
.PP
Flag
.B -o
asks
.I mail2fs
to use the date from the mail to determine where to archive it,
instead of using today's. See the examples section.
.PP
Flag
.B -r
asks
.I mail2fs
to store the entire original message in the
.B raw
file, and not just message headers.
.PP
Flag
.B -D
(accepted by
.I mail2fs
and other programs) enables debug diagnostics.
.PP
The program
.I msgs
is a convenience tool for reading mail. It
generates a mail index. Flag
.B -a
generates a list for all msgs in the mailbox, archived or not. This may
take some time if the mailbox is is big enough.
Flag
.B -s
can be used to include in the list msgs starting with any rune in
.IR runes ,
for example,
.L s
for spam. The mailbox is the standard
.B msgs
inbox unless a different one is supplied as an argument.
As an option, both the mail box path and the name of
a per-month directory can be indicated, to ask
for a list of msgs for just one month. This is useful to
generate per-month mail lists that can be used to quickly
browse existing msgs without going through all msgs in the box.
See the
.I Month
script supplied as an example.
.PP
As an aid for other programs,
.I msgs
places a list of the directories for the msgs listed at
.BR /tmp/msgs.$user ,
which can be useful for retrieve the paths for the msgs
the user is working with.
.PP
Programs just described are the basic toolkit to handle msgs.
Other programs described here are a convenience for the user. Users
are encouraged to customize them and/or to write their own versions.
.PP
.I M
is a script that applies the operation indicated by
.I cmd
to one or more msgs. It applies
.I cmd
to all msgs
last
listed by
.IR msgs ,
(as described by
the paths in
.BR /tmp/msgs.$user ),
when no mail directories are given
as arguments. Arguments selecting msgs only need to mention
paths to the mail directories, but may refer to particular files
within them, as a convenience, to permit using names from
somewhere else without editing.
.I Cmd
may be any of the following:
.TF reply
.TP
.B arch
To archive the msgs as read.
.TP
.B spam
To archive the msgs as spam.
.TP
.B inbox
To archive the msgs as unread.
.TP
.B rm
To print commands to remove the msgs.
.TP
.B print
To print the text of the msgs.
.TP
.B list
To list the directories for the msgs.
.TP
.B mime
To list the attachments for the msgs.
.TP
.B reply
To plumb a reply message to the editor.
.PP
The single letters
.BR a ,
.BR s ,
.BR i ,
.BR d ,
.BR p ,
.BR l ,
.BR m ,
and
.B r
can be used instead of the full
.I cmd
name (in the same order). Note that the letter is the initial for
the command, but for deletion.
.PP
.I Mg
is not strictly necessary, but is supplied as a convenience
script to call
.IR grep (1)
to locate msgs containing the expression given as an
argument. Flag
.B -h
makes it search only in headers. Like the previous program,
.I Mg
only considers msgs listed in
.BR /tmp/msgs.$user .
.PP
.I Mailplumb
is used to send
.IR plumb (1)
messages to maintain
.IR faces (1)
and other programs aware
of msgs in the user's Plan B mailbox, or in
.I mdir
when supplied. Flag
.B -h
makes the program notify existing msgs as new ones.
Flag
.B -o
makes
.I mailplumb
post events for the Octopus, using
.IR  ports (4)
instead of
.IR plumber  (4).
.SS Reading mail in Acme
The program
.I Msgs
(see
.BR /acme/msgs )
is an Acme interface for reading mail.
Its arguments are the same of
.I msgs .
Executing
.I Msgs
within Acme displays a window with the default (or indicated)
mailbox. It understands both the standard mailbox format
(described above) and the virtual folder format (a text file,
see above).
.PP
The program listens to
.I plumber
events for mail and tries to maintain the mail list up to date.
.PP
To read a mail simply click button-3 on the mail file name shown
in the mail list. Archiving, marking a spam, replying, and deleting
messages is achieved by executing the scripts
.IR Arch ,
.IR Spam ,
.IR Reply
and
.IR Delmesg
respectivelly. Most of them may be used either from a message
window or to process standard input (usually at the mail box
directory). Some of them also accept message paths as arguments.
For example, to archive a series of msgs, select them
in the mail list and execute
.B |Arch
in that window.
.PP
Msgs can be sent using
.I Reply
and
.I Post
as described later.
.PP
.I Save
archives one or more messages, adding them to the named file.
.SS Reading mail in O/live
In general, reading mail in
.IR olive (1)
is similar to reading mail in Acme. The main difference is that
there is no need for a mail listing command. That is, there is no
.I Msgs
program.
.PP
Executing
.B !Msgs
at
.B /mail/box/$user/msgs
produces an initial list of msgs. This list can be refreshed
by executing
.B ,<Msgs
for the panel containing the mail list.
To read a mail just click (button-3) on the mail path.
.PP
To select msgs according to text shown in the mail index
use the Sam command language. For example,
.B ,x/9fans/+-p
produces a mail index for msgs comming from
.LR 9fans .
.PP
To archive a set of msgs send their index text as
standard input to
.IR Arch .
For example,
.B ,>Arch
archives all msgs listed in the panel.
In the same way,
.I Spam
flags msgs as spam.
.PP
As in Acme, most scripts can be used
for a panel showing a single message, for standard input, or
for messages given as argument.
.SS Sending mail
.I Mspool
is a program that takes text files from
.B /mail/box/$user/out
reprensenting msgs to be sent, and sends them. It only
operates on files whose names are numbers. To send
a mail, the user creates a file with a randomized name like
.BR /mail/box/$user/out/Out.3452 ,
edits it, and renames the file to just the random number.
.PP
The file format is similar to that used by the
.IR acme (1)
mail composition window. It includes one text line per header,
a blank line, and the body. Attachments are added by
lines starting with
.B Attach:
in the header. Inline attachments are added by lines starting
with
.B Include:
in the header. Replies to other msgs should contain a
.B Replying:
header containing the path to the mail being replied to
(its
.B raw
file in a Plan B mailbox).
.PP
Messages are sent using
.IR marshal (1).
.PP
The script
.I Reply
is available to send messages from either
.IR olive (1)
or
.IR acme (1).
Similar to
.I Arch
and
.IR Spam ,
it replies to the mail shown when executed in a message window (or panel);
it replies to the mail listed in its standard input otherwise. For example,
selecting a mail in the index and executing
.BR .>Reply
in
.I Olive
or
.BR >Reply
in
.I Acme
would reply to it.
.PP
When uncertain regarding the mail to reply to, it creates a window to
edit and send a new mail.
.PP
Mail is delivered by writing the panel created by
.I Reply
and then executing either
.B Send
or
.BR Post .
The former spools the message using
.I mspool ,
the latter attempts to immediatelly deliver the message.
.SH EXAMPLES
Users are expected to customize the scripts supplied to their
needs. All of them are to be considered examples of how to
use the mail system.
.PP
Move all msgs from the Plan 9 mailbox to the Plan B one,
and creates the later if it does not exist.
.EX
; mail2fs -c
.EE
.PP
List msgs:
.EX
; msgs omsgs
200712/4/text       Ralph Corderoy  Re: [9fans] Hi 
200712/3/text       Juan Manuel Se  Re: reunion      
200712/2/text       "Raquel Martin  Re: [Diet] reunion 
200712/1/text       "Fco. J. Balle  reunion      
.EE
.PP
From now on,
.B /tmp/msgs.$user
contains a list of mail directories for
.I M
to work with. For example, 
display them.
.EX
; M p
/mail/box/nemo/msgs/200712/4
To: 9fans@cse.psu.edu
From: Ralph Corderoy <ralph@inputplus.co.uk>
Subject: Re: [9fans] Hi together | a few newbie questions
Sender: 9fans-admin@cse.psu.edu
.I ...
;
.EE
.PP
List their directories and plumb all PDF attachments:
.EX
; M l
/mail/box/nemo/msgs/200712/4
/mail/box/nemo/msgs/200712/3
/mail/box/nemo/msgs/200712/2
/mail/box/nemo/msgs/200712/1
; plumb `{M l}^*.pdf
.EE
.PP
Reply to the second,
mark the first as spam, and archive the others.
.EX
; M r 200712/3
; M s 200712/4/text
; M a
;
.EE
.PP
Prepare to use the script
.I M
(like above) but only for messages from
december 2007 that contain PDF attachments
and are kept in the
.B omsgs
mailbox:
.EX
; ls /mail/box/nemo/omsgs/200712/*/*.pdf >/tmp/msgs.nemo
;
.EE
.PP
Use
.B mailplumb
to see in faces messages in the Plan B mailbox:
.EX
; plumber
; mailplumb
; faces -m /mail/box/$user/msgs
.EE
.PP
This is a guide for reading mail using
.IR olive (1):
.EX
!Msgs	# ask for mail index
!Arch	# archive this mail
!Spam	# mark this mail as spam
X/text/D	# delete all panels showing msgs
, <Msgs	# update mail index
, >Arch	# archive all msgs listed
. >Spam	# mark all messages selected in index as spam
, x/9fans/+-p	# list all 9fans messages shown
.EE
.PP
The script
.B /sys/src/cmd/mail2fs/Month
is an example of a per-month cleanup script. Usually the
directory for the last month is declared as
.B DMTEMP
and this permission is cleared when all spam has been
dealt with. The script also creates cached listings for all but
the current month.
.PP
Add msgs from the UNIX-format
.I oldmbox
to the standard
.I msgs
folder, honoring their dates and inserting them as
archived, and produce a listing for them kept at
.I newfolder
.EX
; mail2fs -aon  oldmbox > /tmp/archived
; mlist </tmp/archived >newfolder
.EE
.PP
Create a cache for September, 2009, to be used by tools
listing msgs.
.EX
; cd /mail/box/$user/msgs
; msgs -a msgs 200909 > 200909.l
.EE
.SH FILES
.TF /mail/box/$user/longname
.TP
.B /mail/box/$user/mbox
Standard Plan 9 mail box.
.TP
.B /mail/box/$user/msgs/
Standard Plan B mail box.
.TP
.BR /tmp/msgs.$user
List of msgs being processed by the user.
.SH SOURCE
.B /sys/src/cmd/upas/mail2fs
and
.B /acme/msgs
.SH SEE ALSO
.IR mail (1).