beets/docs/reference/query.rst
2012-05-01 20:03:01 -07:00

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Queries
=======
Many of beets' :doc:`commands <cli>` are built around **query strings:**
searches that select tracks and albums from your library. This page explains the
query string syntax, which is meant to vaguely resemble the syntax used by Web
search engines.
Keyword
-------
This command::
$ beet list love
will show all tracks matching the query string ``love``. Any unadorned word like this matches *anywhere* in a track's metadata, so you'll see all the tracks with "love" in their title, in their album name, in the artist, and so on.
For example, this is what I might see when I run the command above::
Against Me! - Reinventing Axl Rose - I Still Love You Julie
Air - Love 2 - Do the Joy
Bag Raiders - Turbo Love - Shooting Stars
Bat for Lashes - Two Suns - Good Love
...
Combining Keywords
------------------
Multiple keywords are implicitly joined with a Boolean "and." That is, if a
query has two keywords, it only matches tracks that contain *both* keywords. For
example, this command::
$ beet ls magnetic tomorrow
matches songs from the album "The House of Tomorrow" by The Magnetic Fields in
my library. It *doesn't* match other songs by the Magnetic Fields, nor does it
match "Tomorrowland" by Walter Meego---those songs only have *one* of the two
keywords I specified.
Specific Fields
---------------
Sometimes, a broad keyword match isn't enough. Beets supports a syntax that lets
you query a specific field---only the artist, only the track title, and so on.
Just say ``field:value``, where ``field`` is the name of the thing you're trying
to match (such as ``artist``, ``album``, or ``title``) and ``value`` is the
keyword you're searching for.
For example, while this query::
$ beet list dream
matches a lot of songs in my library, this more-specific query::
$ beet list artist:dream
only matches songs by the artist The-Dream. One query I especially appreciate is
one that matches albums by year::
$ beet list -a year:2011
Recall that ``-a`` makes the ``list`` command show albums instead of individual
tracks, so this command shows me all the releases I have from this year.
Phrases
-------
As of beets 1.0b9, you can query for strings with spaces in them by quoting or escaping them using your shell's argument syntax. For example, this command::
$ beet list the rebel
shows several tracks in my library, but these (equivalent) commands::
$ beet list "the rebel"
$ beet list the\ rebel
only match the track "The Rebel" by Buck 65. Note that the quotes and
backslashes are not part of beets' syntax; I'm just using the escaping
functionality of by shell (bash or zsh, for instance) to pass ``the rebel`` as a
single argument instead of two.
.. _regex:
Regular Expressions
-------------------
While ordinary keywords perform simple substring matches, beets also supports
regular expression matching for more advanced queries. To run a regex query, use
an additional ``:`` between the field name and the expression::
$ beet list 'artist::Ann(a|ie)'
That query finds songs by Anna Calvi and Annie but not Annuals. Similarly, this
query prints the path to any file in my library that's missing a track title::
$ beet list -p title::^$
To search *all* fields using a regular expression, just prefix the expression
with a single `:`, like so::
$ beet list :Ho[pm]eless
Regular expressions are case-sensitive and build on `Python's built-in
implementation`_. See Python's documentation for specifics on regex syntax.
.. _Python's built-in implementation: http://docs.python.org/library/re.html
Path Queries
------------
Sometimes it's useful to find all the items in your library that are
(recursively) inside a certain directory. With beets 1.0b9, use the ``path:``
field to do this::
$ beet list path:/my/music/directory
In fact, beets automatically recognizes any query term containing a path
separator (``/`` on POSIX systems) as a path query, so this command is
equivalent::
$ beet list /my/music/directory
Note that this only matches items that are *already in your library*, so a path
query won't necessarily find *all* the audio files in a directory---just the
ones you've already added to your beets library.