mblaze
—
introduction to the mblaze message system
The mblaze
message system is a set of Unix
utilities for processing and interacting with mail messages which are stored
in maildir folders.
Its design is roughly inspired by MH, the RAND Message Handling
System, but it is a complete implementation from scratch.
mblaze
consists of these Unix utilities
that each do one job:
- maddr(1)
- extract mail addresses from messages
- magrep(1)
- search messages matching a pattern
- mbnc(1)
- bounce messages
- mcom(1)
- compose and send messages
- mdeliver(1)
- deliver messages or import mbox file
- mdirs(1)
- list maildir folders, recursively
- mexport(1)
- export messages as mbox file
- mflag(1)
- manipulate maildir message flags
- mflow(1)
- reflow format=flowed plain text messages
- mfwd(1)
- forward messages
- mgenmid(1)
- generate a Message-ID
- mhdr(1)
- print message headers
- minc(1)
- incorporate new messages
- mless(1)
- conveniently read messages in
less(1)
- mlist(1)
- list and filter messages
- mmime(1)
- create MIME messages
- mmkdir(1)
- create new maildir folders
- mpick(1)
- advanced message filter
- mrefile(1)
- move or copy messages between maildir folders
- mrep(1)
- reply to messages
- mscan(1)
- generate one-line message summaries
- msed(1)
- manipulate message headers
- mseq(1)
- manipulate message sequences
- mshow(1)
- render messages and extract MIME parts
- msort(1)
- sort messages
- mthread(1)
- arrange messages into discussions
mblaze
is a classic command line MUA and
has no features for receiving or transferring messages; you can operate on
messages in a local maildir spool, or fetch your messages using
fdm(1),
getmail(1),
offlineimap(1),
or similar utilities, and send it using
dma(8),
msmtp(1),
sendmail(8),
as provided by OpenSMTPD, Postfix, or similar.
mblaze
operates directly on maildir
folders and doesn't use its own caches or databases. There is no setup
needed for many uses. All utilities have been written with performance in
mind. Enumeration of all messages in a maildir is avoided unless necessary,
and then optimized to limit syscalls. Parsing message metadata is optimized
to limit I/O requests. Initial operations on a large maildir may feel slow,
but as soon as they are in the file system cache, everything is blazingly
fast. The utilities are written to be memory efficient (i.e. not wasteful),
but whole messages are assumed to fit into RAM easily (one at a time).
mblaze
has been written from scratch and
is now well tested, but it is not 100% RFC-conforming (which is neither
worth it, nor desirable). There may be issues with very old, nonconforming,
messages.
mblaze
is written in portable C, using
only POSIX functions (apart from a tiny Linux-only optimization), and has no
external dependencies. It supports MIME and more than 7-bit messages
(everything the host
iconv(3)
can decode). It assumes you work in a UTF-8 environment.
mblaze
works well with other Unix utilities such as
mairix(1),
mu(1), or
offlineimap(1).
mblaze
utilities are designed to be
composed together in a pipe. They are suitable for interactive use and for
scripting, and integrate well into a Unix workflow.
For example, you could decide you want to look at all unseen
messages in your INBOX, oldest first.
mlist -s ~/Maildir/INBOX | msort -d |
mscan
To operate on a set of messages in multiple steps, you can save it
as a sequence, e.g. add a call to ‘mseq
-S
’ to the above command:
mlist -s ~/Maildir/INBOX | msort -d |
mseq -S | mscan
Now mscan will show message numbers and you could look at the
first five messages at once, for example:
mshow 1:5
Likewise, you could decide to incorporate (by moving from
new to cur) all new messages
in all folders, thread it and look at it interactively:
mdirs ~/Maildir | xargs minc |
mthread | mless
Or you could list the attachments of the 20 largest messages in
your INBOX:
mlist ~/Maildir/INBOX | msort -S |
tail -20 | mshow -t
Or apply the patches from the current message:
mshow -O. '*.diff' |
patch
As usual with pipes, the sky is the limit.
mblaze
deals with messages (which are
files), folders (which are maildir folders), sequences (which are
newline-separated lists of messages, possibly saved on disk in
${MBLAZE:-$HOME/.mblaze}/seq), and the current
message (kept as a symlink in
${MBLAZE:-$HOME/.mblaze}/cur).
Messages in the saved sequence can be referred to using special
syntax as explained in
mmsg(7).
Many utilities have a default behavior when used interactively
from a terminal (e.g. operate on the current message or the current
sequence). For scripting, you must make these arguments explicit.
For configuration, see
mblaze-profile(5).