mirror of https://github.com/tstack/lnav.git
163 lines
6.0 KiB
ReStructuredText
163 lines
6.0 KiB
ReStructuredText
.. _ui:
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User Interface
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==============
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The **lnav** TUI displays the content of the current "view" in the middle,
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with status bars above and below, and the interactive prompt as the last line.
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.. figure:: lnav-ui.png
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:align: center
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:alt: Screenshot of lnav showing a mix of syslog and web access_log messages.
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Screenshot of **lnav** viewing syslog messages.
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The default view shows the log messages from the log files that have been
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loaded. There are other views for displaying content like plaintext files
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and SQL results. The :ref:`ui_views` section describes the characteristics of
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each view in more detail. You can switch to the different views using the
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hotkeys described in the :ref:`hotkeys_display` section or by pressing
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:kbd:`ENTER` to activate the breadcrumb bar, moving to the first crumb, and
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then selecting the desired view. You can switch back to the previous view by
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pressing :kbd:`q`. You can switch forward to the new view by pressing
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:kbd:`a`. If the views are time-based (e.g. log and histogram), pressing
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:kbd:`Shift` + :kbd:`q` and :kbd:`Shift` + :kbd:`a` will synchronize the top
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times in the views.
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The right side of the display has a proportionally sized 'scrollbar' that
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shows:
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* the current position in the file;
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* the locations of errors/warnings in the log files by using red or yellow
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coloring;
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* the locations of search hits by using a tick-mark pointing to the left;
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* the locations of bookmarks by using a tick-mark pointing to the right.
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Top Status Bar
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--------------
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The top status bar shows the current time and messages stored in the
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:code:`lnav_user_notifications` table.
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Below the top status bar is the breadcrumb bar that displays the semantic
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location of the top line in the main view. For example, within a
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pretty-printed JSON document, it will show the path to property at the top
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of the view. The actual content of the bar depends on the current view and
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will be updated as you navigate around the main view. The bar can also be
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used to navigate around the document by focusing on it.
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Breadcrumb Bar
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--------------
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.. figure:: lnav-breadcrumbs-help.png
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:align: center
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:figwidth: 90%
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Screenshot of the breadcrumb bar focused and navigating the help text
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To focus on the breadcrumb bar, press :kbd:`ENTER`. The :kbd:`←`/:kbd:`→`
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cursor keys can be used to select a crumb and the :kbd:`↑`/:kbd:`↓` keys can
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be used select a value of that crumb. To accept a value and drop focus on the
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bar, press :kbd:`ENTER`. To accept a value and move to the next crumb, press
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:kbd:`→`. Using :kbd:`→` makes it quicker to drill down into a document
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without having to constantly switch focus. To drop focus on the bar without
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accepting anything, press :kbd:`Escape`.
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There are three types of crumbs:
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* a dropdown where one of a limited set of values can be selected;
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* a combobox where a value can be entered directly or selected;
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* a numeric input for entering array indexes.
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When a dropdown or combobox is selected, you can type part of the desired value
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to filter the list of values. For example, the first crumb is always the
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current view, typing in "hi" will filter the list down to the "HIST" value.
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Configuration Panels
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--------------------
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After the main view content, there is a header bar for two configuration
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panels: Files and Filters. These panels provide visual access to parts of
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lnav's configuration.
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The Files panel is open initially to display progress in loading files.
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The following information can be displayed for each file:
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* the "unique" portion of the path relative to the other files;
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* the amount of data that has been indexed;
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* the date range of log messages contained in the file;
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* the errors that were encountered while trying to index the file;
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* the notes recorded for files where some automatic action was taken,
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like hiding the file if it was seen as a duplicate of another file.
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If the view supports filtering, there will be a status line showing the
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following:
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* the number of enabled filters and the total number of filters;
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* the number of lines that are **not** displayed because of filtering.
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To edit the filters, you can press TAB to change the focus from the main
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view to the filter editor. The editor allows you to create, enable/disable,
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and delete filters easily.
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Finally, the last line on the display is where you can enter search
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patterns and execute internal commands, such as converting a
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unix-timestamp into a human-readable date. The command-line is by
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the readline library, so the usual set of keyboard shortcuts can
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be used.
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The body of the display is also used to display other content, such
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as: the help file, histograms of the log messages over time, and
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SQL results. The views are organized into a stack so that any time
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you activate a new view with a key press or command, the new view
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is pushed onto the stack. Pressing the same key again will pop the
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view off of the stack and return you to the previous view. Note
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that you can always use 'q' to pop the top view off of the stack.
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.. _ui_views:
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Views
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-----
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LOG
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^^^
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The log view displays the log messages from any loaded log files in time
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order.
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On color displays, the log messages will be highlighted as follows:
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* Errors will be colored in red;
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* warnings will be yellow;
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* search hits are reverse video;
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* various color highlights will be applied to: IP addresses, SQL keywords,
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XML tags, file and line numbers in Java backtraces, and quoted strings;
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* "identifiers" in the messages will be randomly assigned colors based on their
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content (works best on "xterm-256color" terminals).
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.. note::
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If the coloring is too much for your tastes, you can change to the
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"grayscale" theme by entering the following command:
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.. code-block:: lnav
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:config /ui/theme grayscale
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The breadcrumb bar will show:
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* the timestamp
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* the log format for the top line;
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* the name of the file the top line was pulled from;
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* the line number for the top line in the display;
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* the current search hit, the total number of hits, and the search term;
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DB
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^^
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HELP
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^^^^
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HIST
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^^^^
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