lib: Clarify internal documentation of _notmuch_database_filename_to_direntry

[notmuch] / notmuch.1

.\" notmuch - Not much of an email program, (just index, search and tagging)
.\"
.\" Copyright © 2009 Carl Worth
.\"
.\" Notmuch is free software: you can redistribute it and/or modify
.\" it under the terms of the GNU General Public License as published by
.\" the Free Software Foundation, either version 3 of the License, or
.\" (at your option) any later version.
.\"
.\" Notmuch is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public License
.\" along with this program.  If not, see http://www.gnu.org/licenses/ .
.\"
.\" Author: Carl Worth <cworth@cworth.org>
.TH NOTMUCH 1 2009-10-31 "Notmuch 0.1"
.SH NAME
notmuch \- thread-based email index, search, and tagging
.SH SYNOPSIS
.B notmuch
.IR command " [" args " ...]"
.SH DESCRIPTION
Notmuch is a command-line based program for indexing, searching,
reading, and tagging large collections of email messages.

The quickest way to get started with Notmuch is to simply invoke the
.B notmuch
command with no arguments, which will interactively guide you through
the process of indexing your mail.
.SH NOTE
While the command-line program
.B notmuch
provides powerful functionality, it does not provide the most
convenient interface for that functionality. More sophisticated
interfaces are expected to be built on top of either the command-line
interface, or more likely, on top of the notmuch library
interface. See http://notmuchmail.org for more about alternate
interfaces to notmuch.
.SH COMMANDS
The
.BR setup
command is used to configure Notmuch for first use, (or to reconfigure
it later).
.RS 4
.TP 4
.B setup

Interactively sets up notmuch for first use.

The setup command will prompt for your full name, your primary email
address, any alternate email addresses you use, and the directory
containing your email archives. Your answers will be written to a
configuration file in ${NOTMUCH_CONFIG} (if set) or
${HOME}/.notmuch-config . This configuration file will be created with
descriptive comments, making it easy to edit by hand later to change the
configuration. Or you can run
.B "notmuch setup"
again to change the configuration.

The mail directory you specify can contain any number of
sub-directories and should primarily contain only files with individual
email messages (eg. maildir or mh archives are perfect). If there are
other, non-email files (such as indexes maintained by other email
programs) then notmuch will do its best to detect those and ignore
them.

Mail storage that uses mbox format, (where one mbox file contains many
messages), will not work with notmuch. If that's how your mail is
currently stored, it is recommended you first convert it to maildir
format with a utility such as mb2md before running
.B "notmuch setup" .

Invoking
.B notmuch
with no command argument will run
.B setup
if the setup command has not previously been completed.
.RE

The
.B new
command is used to incorporate new mail into the notmuch database.
.RS 4
.TP 4
.B new

Find and import any new messages to the database.

The
.B new
command scans all sub-directories of the database, performing
full-text indexing on new messages that are found. Each new message
will automatically be tagged with both the
.BR inbox " and " unread
tags.

You should run
.B "notmuch new"
once after first running
.B "notmuch setup"
to create the initial database. The first run may take a long time if
you have a significant amount of mail (several hundred thousand
messages or more). Subsequently, you should run
.B "notmuch new"
whenever new mail is delivered and you wish to incorporate it into the
database. These subsequent runs will be much quicker than the initial
run.

Invoking
.B notmuch
with no command argument will run
.B new
if
.B "notmuch setup"
has previously been completed, but
.B "notmuch new"
has not previously been run.
.RE

Several of the notmuch commands accept search terms with a common
syntax. See the
.B "SEARCH SYNTAX"
section below for more details on the supported syntax.

The
.BR search " and "show
commands are used to query the email database.
.RS 4
.TP 4
.BR search " [options...] <search-term>..."

Search for messages matching the given search terms, and display as
results the threads containing the matched messages.

The output consists of one line per thread, giving a thread ID, the
date of the newest (or oldest, depending on the sort option) matched
message in the thread, the number of matched messages and total
messages in the thread, the names of all participants in the thread,
and the subject of the newest (or oldest) message.

Supported options for
.B search
include
.RS 4
.TP 4
.BR \-\-sort= ( newest\-first | oldest\-first )

This option can be used to present results in either chronological order
.RB ( oldest\-first )
or reverse chronological order
.RB ( newest\-first ).

Note: The thread order will be distinct between these two options
(beyond being simply reversed). When sorting by
.B oldest\-first
the threads will be sorted by the oldest message in each thread, but
when sorting by
.B newest\-first
the threads will be sorted by the newest message in each thread.

.RE
.RS 4
By default, results will be displayed in reverse chronological order,
(that is, the newest results will be displayed first).

See the
.B "SEARCH SYNTAX"
section below for details of the supported syntax for <search-terms>.
.RE
.TP
.BR show " [options...] <search-term>..."

Shows all messages matching the search terms.

The messages will be grouped and sorted based on the threading (all
replies to a particular message will appear immediately after that
message in date order). The output is not indented by default, but
depth tags are printed so that proper indentation can be performed by
a post-processor (such as the emacs interface to notmuch).

Supported options for
.B show
include
.RS 4
.TP 4
.B \-\-entire\-thread

By default only those messages that match the search terms will be
displayed. With this option, all messages in the same thread as any
matched message will be displayed.
.RE

.RS 4
The  output format  is plain-text,  with all  text-content  MIME parts
decoded. Various components in the output,
.RB ( message ", " header ", " body ", " attachment ", and MIME " part ),
will be delimited by easily-parsed markers. Each marker consists of a
Control-L character (ASCII decimal 12), the name of the marker, and
then either an opening or closing brace, ('{' or '}'), to either open
or close the component.

A common use of
.B notmuch show
is to display a single thread of email messages. For this, use a
search term of "thread:<thread-id>" as can be seen in the first
column of output from the
.B notmuch search
command.

See the
.B "SEARCH SYNTAX"
section below for details of the supported syntax for <search-terms>.
.RE
.RE

The
.B reply
command is useful for preparing a template for an email reply.
.RS 4
.TP 4
.BR reply " [options...] <search-term>..."

Constructs a reply template for a set of messages.

To make replying to email easier,
.B notmuch reply
takes an existing set of messages and constructs a suitable mail
template. The Reply-to header (if any, otherwise From:) is used for
the To: address. Vales from the To: and Cc: headers are copied, but
not including any of the current user's email addresses (as configured
in primary_mail or other_email in the .notmuch-config file) in the
recipient list

It also builds a suitable new subject, including Re: at the front (if
not already present), and adding the message IDs of the messages being
replied to to the References list and setting the In-Reply-To: field
correctly.

Finally, the original contents of the emails are quoted by prefixing
each line with '> ' and included in the body.

The resulting message template is output to stdout.

Supported options for
.B reply
include
.RS
.TP 4
.BR \-\-format= ( default | headers\-only )
.RS
.TP 4
.BR default
Includes subject and quoted message body.
.TP
.BR headers-only
Only produces In-Reply-To, References, To, Cc, and Bcc headers.
.RE

See the
.B "SEARCH SYNTAX"
section below for details of the supported syntax for <search-terms>.

Note: It is most common to use
.B "notmuch reply"
with a search string matching a single message, (such as
id:<message-id>), but it can be useful to reply to several messages at
once. For example, when a series of patches are sent in a single
thread, replying to the entire thread allows for the reply to comment
on issue found in multiple patches.
.RE
.RE

The
.B tag
command is the only command available for manipulating database
contents.

.RS 4
.TP 4
.BR tag " +<tag>|-<tag> [...] [--] <search-term>..."

Add/remove tags for all messages matching the search terms.

Tags prefixed by '+' are added while those prefixed by '-' are
removed. For each message, tag removal is performed before tag
addition.

The beginning of <search-terms> is recognized by the first
argument that begins with neither '+' nor '-'. Support for
an initial search term beginning with '+' or '-' is provided
by allowing the user to specify a "--" argument to separate
the tags from the search terms.

See the
.B "SEARCH SYNTAX"
section below for details of the supported syntax for <search-terms>.
.RE

The
.BR dump " and " restore
commands can be used to create a textual dump of email tags for backup
purposes, and to restore from that dump

.RS 4
.TP 4
.BR dump " [<filename>]"

Creates a plain-text dump of the tags of each message.

The output is to the given filename, if any, or to stdout.

These tags are the only data in the notmuch database that can't be
recreated from the messages themselves.  The output of notmuch dump is
therefore the only critical thing to backup (and much more friendly to
incremental backup than the native database files.)
.TP
.BR restore " <filename>"

Restores the tags from the given file (see
.BR "notmuch dump" "."

Note: The dump file format is specifically chosen to be
compatible with the format of files produced by sup-dump.
So if you've previously been using sup for mail, then the
.B "notmuch restore"
command provides you a way to import all of your tags (or labels as
sup calls them).
.SH SEARCH SYNTAX
Several notmuch commands accept a common syntax for search terms.

The search terms can consist of free-form text (and quoted phrases)
which will match all messages that contain all of the given
terms/phrases in the body, the subject, or any of the sender or
recipient headers.

In addition to free text, the following prefixes can be used to force
terms to match against specific portions of an email, (where
<brackets> indicate user-supplied values):

        from:<name-or-address>

        to:<name-or-address>

        subject:<word-or-quoted-phrase>

        attachment:<word>

        tag:<tag>

        id:<message-id>

        thread:<thread-id>

The
.B from:
prefix is used to match the name or address of the sender of an email
message.

The
.B to:
prefix is used to match the names or addresses of any recipient of an
email message, (whether To, Cc, or Bcc).

Any term prefixed with
.B subject:
will match only text from the subject of an email. Searching for a
phrase in the subject is supported by including quotation marks around
the phrase, immediately following
.BR subject: .

The
.B attachment:
prefix can be used to search for specific filenames (or extensions) of
attachments to email messages.

For
.BR tag: ,
valid tag values include
.BR inbox " and " unread
by default for new messages added by
.B notmuch new
as well as any other tag values added manually with
.BR "notmuch tag" .

For
.BR id: ,
message ID values are the literal contents of the Message-ID: header
of email messages, but without the '<', '>' delimiters.

The
.B thread:
prefix can be used with the thread ID values that are generated
internally by notmuch (and do not appear in email messages). These
thread ID values can be seen in the first column of output from
.B "notmuch search"

In addition to individual terms, multiple terms can be
combined with Boolean operators (
.BR and ", " or ", " not
, etc.). Each term in the query will be implicitly connected by a
logical AND if no explicit operator is provided, (except that terms
with a common prefix will be implicitly combined with OR until we get
Xapian defect #402 fixed).

Parentheses can also be used to control the combination of the Boolean
operators, but will have to be protected from interpretation by the
shell, (such as by putting quotation marks around any parenthesized
expression).

Finally, results can be restricted to only messages within a
particular time range, (based on the Date: header) with a syntax of:

        <intial-timestamp>..<final-timestamp>

Each timestamp is a number representing the number of seconds since
1970-01-01 00:00:00 UTC. This is not the most convenient means of
expressing date ranges, but until notmuch is fixed to accept a more
convenient form, one can use the date program to construct
timestamps. For example, with the bash shell the folowing syntax would
specify a date range to return messages from 2009-10-01 until the
current time:

        $(date +%s -d 2009-10-01)..$(date +%s)
.SH SEE ALSO
The emacs-based interface to notmuch (available as
.B notmuch.el
in the Notmuch distribution).

The notmuch website:
.B http://notmuchmail.org
.SH CONTACT
Feel free to send questions, comments, or kudos to the notmuch mailing
list <notmuch@notmuchmail.org> . Subscription is not required before
posting, but is available from the notmuchmail.org website.

Real-time interaction with the Notmuch community is available via IRC
(server: irc.freenode.net, channel: #notmuch).