lnav/docs/source/sqltab.rst

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.. _sql-tab:
SQLite Tables Reference
=======================
In addition to the tables generated for each log format, **lnav** includes
the following tables/views:
* `environ`_
* `lnav_events`_
* `lnav_file`_
* `lnav_file_metadata`_
* `lnav_user_notifications`_
* `lnav_views`_
* `lnav_views_echo`_
* `lnav_view_files`_
* `lnav_view_stack`_
* `lnav_view_filters`_
* `lnav_view_filter_stats`_
* `lnav_view_filters_and_stats`_
* `all_logs`_
* `http_status_codes`_
* `regexp_capture(<string>, <regex>)`_
These extra tables provide useful information and can let you manipulate
**lnav**'s internal state. You can get a dump of the entire database schema
by executing the '.schema' SQL command, like so::
;.schema
environ
-------
The **environ** table gives you access to the **lnav** process' environment
variables. You can :code:`SELECT`, :code:`INSERT`, and :code:`UPDATE`
environment variables, like so:
.. code-block:: custsqlite
;SELECT * FROM environ WHERE name = 'SHELL'
name value
SHELL /bin/tcsh
;UPDATE environ SET value = '/bin/sh' WHERE name = 'SHELL'
Environment variables can be used to store simple values or pass values
from **lnav**'s SQL environment to **lnav**'s commands. For example, the
:code:`:open` command will do variable substitution, so you can insert a variable
named "FILENAME" and then open it in **lnav** by referencing it with
"$FILENAME":
.. code-block:: custsqlite
;INSERT INTO environ VALUES ('FILENAME', '/path/to/file')
:open $FILENAME
.. _table_lnav_events:
lnav_events
-----------
The :code:`lnav_events` table allows you to react to events that occur while
**lnav** is running using SQLite triggers. For example, when a file is
opened, a row is inserted into the :code:`lnav_events` table that contains
a timestamp and a JSON object with the event ID and the path of the file.
The following columns are available in this table:
:ts: The timestamp of the event.
:content: A JSON object that contains the event information. See the
:ref:`event_reference` for more information about the types
of events that are available.
lnav_file
---------
The :code:`lnav_file` table allows you to examine and perform limited updates to
the metadata for the files that are currently loaded into **lnav**. The
following columns are available in this table:
:device: The device the file is stored on.
:inode: The inode for the file on the device.
:filepath: If this is a real file, it will be the absolute path. Otherwise,
it is a symbolic name. If it is a symbolic name, it can be UPDATEd so that
this file will be considered when saving and loading session information.
:format: The log file format for the file.
:lines: The number of lines in the file.
:time_offset: The millisecond offset for timestamps. This column can be
UPDATEd to change the offset of timestamps in the file.
lnav_file_metadata
------------------
The :code:`lnav_file_metadata` table gives access to metadata associated with a
loaded file. Currently,
:filepath: The path to the file.
:descriptor: A descriptor that identifies the source of the metadata. The
following descriptors are supported:
:net.zlib.gzip.header: The header on a gzipped file. The content is a
JSON object with the following properties:
:name: The original name of the file.
:mtime: The last modified time of the file when it was compressed.
:comment: A text comment associated with the file.
:net.daringfireball.markdown.frontmatter: The frontmatter on a
markdown file. If the frontmatter is delimited by three dashes
(:code:`---`), the :code:`mimetype` will be :code:`application/yaml`.
If the frontmatter is delimited by three pluses (:code:`+++`) the
:code:`mimetype` will be :code:`application/toml`.
:mimetype: The MIME type of the metadata.
:content: The metadata itself.
.. _table_lnav_user_notifications:
lnav_user_notifications
-----------------------
The :code:`lnav_user_notifications` table allows you to display a custom message
in the top-right corner of the UI. For example, to display "Hello, World!",
you can enter:
.. code-block:: custsqlite
;REPLACE INTO lnav_user_notifications (message) VALUES ('Hello, World!')
There are additional columns to have finer control of what is displayed and
when:
:id: The unique ID for the message, defaults to "org.lnav.user". This is
the primary key for the table, so more than one type of message is not
allowed.
:priority: The priority of the message. Higher priority messages will be
displayed until they are cleared or are expired.
:created: The time the message was created.
:expiration: The time when the message should expire or NULL if it should
not automatically expire.
:views: A JSON array of view names where the message is applicable or NULL
if the message should be shown in all views.
:message: The message itself.
This table will most likely be used in combination with :ref:`Events` and the
`lnav_views_echo`_ table.
lnav_views
----------
The :code:`lnav_views` table allows you to SELECT and UPDATE information related
to **lnav**'s "views" (e.g. log, text, ...). The following columns are
available in this table:
:name: The name of the view.
:top: The line number at the top of the view. This value can be UPDATEd to
move the view to the given line.
:left: The left-most column number to display. This value can be UPDATEd to
move the view left or right.
:height: The number of lines that are displayed on the screen.
:inner_height: The number of lines of content being displayed.
:top_time: The timestamp of the top line in the view or NULL if the view is
not time-based. This value can be UPDATEd to move the view to the given
time.
:top_file: The file the top line in the view is from.
:paused: Indicates if the view is paused and will not load new data.
:search: The search string for this view. This value can be UPDATEd to
initiate a text search in this view.
:filtering: Indicates if the view is applying filters.
:movement: The movement mode, either 'top' or 'cursor'.
:top_meta: A JSON object that contains metadata related to the top line
in the view.
:selection: The number of the line that is focused for selection.
:options: A JSON object that contains optional settings for this view.
lnav_views_echo
---------------
The :code:`lnav_views_echo` table is a real SQLite table that you can create
TRIGGERs on in order to react to users moving around in a view.
.. note::
The table is periodically updated to reflect the current state of the views.
The changes are *not* performed immediately after the user action.
lnav_view_files
---------------
The :code:`lnav_view_files` table provides access to details about the files
displayed in a particular view. The main purpose of this table is to allow
you to programmatically control which files are shown / hidden in the view.
The following columns are available in this table:
:view_name: The name of the view.
:filepath: The file's path.
:visible: Determines whether the file is visible in the view. This column
can be changed using an :code:`UPDATE` statement to hide or show the file.
lnav_view_stack
---------------
The :code:`lnav_view_stack` table allows you to :code:`SELECT` and :code:`DELETE`
from the stack of **lnav** "views" (e.g. log, text, ...). The following columns
are available in this table:
:name: The name of the view.
.. _table_lnav_view_filters:
lnav_view_filters
-----------------
The :code:`lnav_view_filters` table allows you to manipulate the filters in the
**lnav** views. The following columns are available in this table:
:view_name: The name of the view the filter is applied to.
:filter_id: The filter identifier. This will be assigned on insertion.
:enabled: Indicates whether this filter is enabled or disabled.
:type: The type of filter, either 'in' or 'out'.
:pattern: The regular expression to filter on.
This table supports :code:`SELECT`, :code:`INSERT`, :code:`UPDATE`, and
:code:`DELETE` on the table rows to read, create, update, and delete
filters for the views.
lnav_view_filter_stats
----------------------
The :code:`lnav_view_filter_stats` table allows you to get information about how
many lines matched a given filter. The following columns are available in
this table:
:view_name: The name of the view.
:filter_id: The filter identifier.
:hits: The number of lines that matched this filter.
This table is read-only.
lnav_view_filters_and_stats
---------------------------
The :code:`lnav_view_filters_and_stats` view joins the :code:`lnav_view_filters`
table with the :code:`lnav_view_filter_stats` table into a single view for ease of use.
all_logs
--------
.. f0:sql.tables.all_logs
The :code:`all_logs` table lets you query the format derived from the **lnav**
log message parser that is used to automatically extract data, see
:ref:`data-ext` for more details.
http_status_codes
-----------------
The :code:`http_status_codes` table is a handy reference that can be used to turn
HTTP status codes into human-readable messages.
regexp_capture(<string>, <regex>)
---------------------------------
The :code:`regexp_capture()` table-valued function applies the regular expression
to the given string and returns detailed results for the captured portions of
the string.