#+TITLE: MU FIND
#+MAN_CLASS_OPTIONS: :section-id "@SECTION_ID@" :date "@MAN_DATE@"

* NAME

*mu find* - find e-mail messages in the *mu* database.

* SYNOPSIS

*mu [common-options] find [options] <search expression>*

* DESCRIPTION

*mu find* is the *mu* command for searching e-mail message that were stored earlier
using *mu index(1)*.

* SEARCHING MAIL

*mu find* starts a search for messages in the database that match some search
pattern. The search patterns are described in detail in *mu-query(7)*.

For example:

#+begin_example
$ mu find subject:snow and date:2009..
#+end_example

would find all messages in 2009 with 'snow' in the subject field, e.g:

#+begin_example
2009-03-05 17:57:33 EET Lucia  <lucia@example.com> running in the snow
2009-03-05 18:38:24 EET Marius <marius@foobar.com> Re: running in the snow
#+end_example

Note, this the default, plain-text output, which is the default, so you don't
have to use *--format=plain*. For other types of output (such as symlinks, XML or
s-expressions), see the discussion in the *OPTIONS*-section below about *--format*.

The search pattern is taken as a command-line parameter. If the search
parameter consists of multiple parts (as in the example) they are
treated as if there were a logical *and* between them.

For details on the possible queries, see *mu-query(7)*.

* FIND OPTIONS

Note, some of the important options are described in the *mu*(1) man-page
and not here, as they apply to multiple mu-commands.

The *find*-command has various options that influence the way *mu* displays the
results. If you don't specify anything, the defaults are ~fields="d f s"~,
~--sortfield=date~ and ~--reverse~.

** -f, --fields=<fields>
specifies a string that determines which fields are shown in the output. This
string consists of a number of characters (such as 's' for subject or 'f' for
from), which will replace with the actual field in the output. Fields that are
not known will be output as-is, allowing for some simple formatting.

For example:

#+begin_example
$ mu find subject:snow --fields "d f s"
#+end_example

lists the date, subject and sender of all messages with 'snow' in the their
subject.

The table of replacement characters is superset of the list mentions for search
parameters, such as:
#+begin_example
	t       *t*o: recipient
	d       Sent *d*ate of the message
	f       Message sender (*f*rom:)
	g       Message flags (fla*g*s)
	l       Full path to the message (*l*ocation)
	s       Message *s*ubject
	i       Message-*i*d
	m       *m*aildir
#+end_example

For the complete list, try the command: ~mu info fields~.

The message flags are described in *mu-query(7)*. As an example, a message which
is 'seen', has an attachment and is signed would have 'asz' as its corresponding
output string, while an encrypted new message would have 'nx'.

** -s, --sortfield=<field> and -z,--reverse
specify the field to sort the search results by and the direction (i.e.,
'reverse' means that the sort should be reverted - Z-A). Examples include:

#+begin_example
	cc,c            Cc (carbon-copy) recipient(s)
	date,d          Message sent date
	from,f          Message sender
	maildir,m       Maildir
	msgid,i         Message id
	prio,p          Nessage priority
	subject,s       Message subject
	to,t            To:-recipient(s)
#+end_example

For the complete list, try the command: ~mu info fields~.

Thus, for example, to sort messages by date, you could specify:

#+begin_example
$ mu find fahrrad --fields "d f s" --sortfield=date --reverse
#+end_example

Note, if you specify a sortfield, by default, messages are sorted in reverse
(descending) order (e.g., from lowest to highest). This is usually a good
choice, but for dates it may be more useful to sort in the opposite direction.

** -n, --maxnum=<number>
If > 0, display maximally that number of entries. If not specified, all matching
entries are displayed.

** --summary-len=<number>
If > 0, use that number of lines of the message to provide a summary.

** --format=<plain|links|xquery|xml|sexp>

output results in the specified format:

- The default is *plain*, i.e normal output with one line per message.
- *links* outputs the results as a maildir with symbolic links to the found
  messages. This enables easy integration with mail-clients (see below for more
  information).
- *xml* formats the search results as XML.
- *sexp* formats the search results as an s-expression as used in Lisp programming
  environments.
- *xquery* shows the Xapian query corresponding to your search terms. This is
  meant for for debugging purposes.

** --linksdir=<dir> and -c, --clearlinks
when using ~-format=links~, output the results as a maildir with symbolic links to
the found messages. This enables easy integration with mail-clients (see below
for more information). *mu* will create the maildir if it does not exist yet.

If you specify ~--clearlinks~, existing symlinks will be cleared from the target
directories; this allows for re-use of the same maildir. However, this option
will delete any symlink it finds, so be careful.

#+begin_example
$ mu find grolsch --format=links --linksdir=~/Maildir/search --clearlinks
#+end_example

stores links to found messages in =~/Maildir/search=. If the directory does not
exist yet, it will be created. Note: when *mu* creates a Maildir for these links,
it automatically inserts a =.noindex= file, to exclude the directory from *mu
index*.

** --after=<timestamp>
only show messages whose message files were last modified (*mtime*) after
=<timestamp>=. =<timestamp>= is a UNIX *time_t* value, the number of seconds since
1970-01-01 (in UTC).

From the command line, you can use the *date* command to get this value. For
example, only consider messages modified (or created) in the last 5 minutes, you
could specify
#+begin_example
  --after=`date +%s --date='5 min ago'`
#+end_example
This is assuming the GNU *date* command.

** --exec=<command>
the ~--exec~ coption causes the =command= to be executed on each matched message;
for example, to see the raw text of all messages matching 'milkshake', you could
use:
#+begin_example
$ mu find milkshake --exec='less'
#+end_example
which is roughly equivalent to:
#+begin_example
$ mu find milkshake --fields="l" | xargs less
#+end_example

** -b, --bookmark=<bookmark>
use a bookmarked search query. Using this option, a query from your bookmark
file will be prepended to other search queries. See *mu-bookmarks(5)* for the
details of the bookmarks file.


** -u, --skip-dups
whenever there are multiple messages with the same message-id field, only show
the first one. This is useful if you have copies of the same message, which is a
common occurrence when using e.g. Gmail together with *offlineimap*.

** -r, --include-related
include messages being referred to by the matched messages -- i.e.. include
messages that are part of the same message thread as some matched messages. This
is useful if you want Gmail-style 'conversations'.

** -t, --threads
show messages in a 'threaded' format -- that is, with indentation and arrows
showing the conversation threads in the list of matching messages. When using
this, sorting is chronological (by date), based on the newest message in a
thread.

Messages in the threaded list are indented based on the depth in the discussion,
and are prefix with a kind of arrow with thread-related information about the
message, as in the following table:
#+begin_example
|             | normal | orphan | duplicate |
|-------------+--------+--------+-----------|
| first child | `->    | `*>    | `=>       |
| other       | |->    | |*>    | |=>       |
#+end_example

Here, an 'orphan' is a message without a parent message (in the list of
matches), and a duplicate is a message whose message-id was already seen before;
not this may not really be the same message, if the message-id was copied.

The algorithm used for determining the threads is based on Jamie Zawinksi's
description: http://www.jwz.org/doc/threading.html

#+include: "muhome.inc" :minlevel 2

#+include: "common-options.inc" :minlevel 1

* INTEGRATION

It is possible to integrate *mu find* with some mail clients

** *mutt*

For *mutt* you can use the following in your =muttrc=; pressing the F8 key will
start a search, and F9 will take you to the results.

#+begin_example
# mutt macros for mu
macro index <F8> "<shell-escape>mu find --clearlinks --format=links --linksdir=~/Maildir/search " \\
					"mu find"
macro index <F9> "<change-folder-readonly>~/Maildir/search" \\
					"mu find results"
#+end_example


** *Wanderlust*

*Sam B* suggested the following on the *mu*-mailing list. First add the following to
your Wanderlust configuration file:

#+begin_example
(require 'elmo-search)
(elmo-search-register-engine
    'mu 'local-file
    :prog "/usr/local/bin/mu" ;; or wherever you've installed it
    :args '("find" pattern "--fields" "l") :charset 'utf-8)

(setq elmo-search-default-engine 'mu)
;; for when you type "g" in folder or summary.
(setq wl-default-spec "[")
#+end_example

Now, you can search using the *g* key binding; you can also create permanent
virtual folders when the messages matching some expression by adding something
like the following to your =folders= file.

#+begin_example
VFolders {
  [date:today..now]!mu  "Today"
  [size:1m..100m]!mu    "Big"
  [flag:unread]!mu      "Unread"
}
#+end_example

After restarting Wanderlust, the virtual folders should appear.

* ENCODING

*mu find* output is encoded according to the locale for =--format=plain= (the
default format), and UTF-8 for all other formats (=sexp=, =xml=).


* PERFORMANCE

Some notes on performance, comparing the timings between some recent releases;
taking the total number for 10 test runs.

1. time (repeat 10 mu find "" -n 50000 > /dev/null)
2. time (repeat 10 mu find "" -n 50000 --include-related --threads > /dev/null)


|       release | time 1 (sec) | time 2 (sec) |
|---------------+--------------+--------------|
|           1.4 | 8.9s         | 59.3s        |
|           1.6 | 8.3s         | 27.5s        |
|           1.8 | 8.7s         | 29.3s        |
|          1.10 | 9.8s         | 30.6s        |
| 1.11 (master) | 10.1s        | 29.5s        |




#+include: "exit-code.inc" :minlevel 1

#+include: "bugs.inc" :minlevel 1

#+include: "author.inc" :minlevel 1

#+include: "copyright.inc" :minlevel 1

* SEE ALSO

*mu(1)*, *mu-index(1)*, *mu-query(7)*, *mu-info(1)*
