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1006 lines
44 KiB
Plaintext
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lnav - A fancy log file viewer
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DESCRIPTION
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===========
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The log file navigator, lnav, is an enhanced log file viewer that
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takes advantage of any semantic information that can be gleaned from
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the files being viewed, such as timestamps and log levels. Using this
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extra semantic information, lnav can do things like interleaving
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messages from different files, generate histograms of messages over
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time, and providing hotkeys for navigating through the file. It is
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hoped that these features will allow the user to quickly and
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efficiently zero in on problems.
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OPENING PATHS/URLs
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==================
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The main arguments to lnav are the files, directories, glob patterns,
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or URLs to be viewed. If no arguments are given, the default syslog
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file for your system will be opened. These arguments will be polled
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periodically so that any new data or files will be automatically
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loaded. If a previously loaded file is removed or replaced, it will
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be closed and the replacement opened.
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Note: When opening SFTP URLs, if the password is not provided for the
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host, the SSH agent can be used to do authentication.
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OPTIONS
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=======
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Lnav takes a list of files to view and/or you can use the flag
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arguments to load well-known log files, such as the syslog log
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files. The flag arguments are:
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-a Load all of the most recent log file types.
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-r Recursively load files from the given directory hierarchies.
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-R Load older rotated log files as well.
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When using the flag arguments, lnav will look for the files relative
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to the current directory and its parent directories. In other words,
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if you are working within a directory that has the well-known log
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files, those will be preferred over any others.
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If you do not want the default syslog file to be loaded when
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no files are specified, you can pass the '-N' flag.
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Any files given on the command-line are scanned to determine their log
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file format and to create an index for each line in the file. You do
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not have to manually specify the log file format. The currently
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supported formats are: syslog, apache, strace, tcsh history, and
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generic log files with timestamps.
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Lnav will also display data piped in on the standard input. The
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following options are available when doing so:
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-t Prepend timestamps to the lines of data being read in
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on the standard input.
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-w file Write the contents of the standard input to this file.
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To automatically execute queries or lnav commands after the files
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have been loaded, you can use the following options:
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-c cmd A command, query, or file to execute. The first character
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determines the type of operation: a colon is used for the
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built-in commands; a semi-colon for SQL queries; and a
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pipe symbol (|) for executing a file containing other
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commands. For example, to open the file "foo.log" and go
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to the tenth line in the file, you can do:
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lnav -c ':goto 10' foo.log
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This option can be given multiple times to execute multiple
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operations in sequence.
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-f file A file that contains commands, queries, or files to execute.
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This option is a shortcut for "-c '|file'". You can use a
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dash (-) to execute commands from the standard input.
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To execute commands/queries without the opening the interactive text UI,
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you can pass the '-n' option. This combination of options allows you to
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write scripts for processing logs with lnav. For example, to get a list
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of IP addresses that dhclient has bound to in CSV format:
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#! /usr/bin/lnav -nf
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# Usage: dhcp_ip.lnav /var/log/messages
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# Only include lines that look like:
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# Apr 29 00:31:56 example-centos5 dhclient: bound to 10.1.10.103 -- renewal in 9938 seconds.
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:filter-in dhclient: bound to
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# The log message parser will extract the IP address as col_0, so we
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# select that and alias it to "dhcp_ip".
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;select distinct col_0 as dhcp_ip from logline;
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# Finally, write the results of the query to stdout.
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:write-csv-to -
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DISPLAY
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=======
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The main part of the display shows the log lines from the files interleaved
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based on time-of-day. New lines are automatically loaded as they are appended
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to the files and, if you are viewing the bottom of the files, lnav will scroll
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down to display the new lines, much like 'tail -f'.
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On color displays, the lines will be highlighted as follows:
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* Errors will be colored in ${ansi_red}red${ansi_norm};
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* warnings will be ${ansi_yellow}yellow${ansi_norm};
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* boundaries between days will be ${ansi_underline}underlined${ansi_norm}; and
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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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To give you an idea of where you are spatially, the right side of the
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display has a proportionally sized 'scroll bar' that indicates your
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current position in the files. The scroll bar will also show areas of
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the file where warnings or errors are detected by coloring the bar
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yellow or red, respectively. Tick marks will also be added to the
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left and right hand side of the bar, for search hits and bookmarks.
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A bar on the left side is color coded and broken up to indicate which
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messages are from the same file. Pressing the left-arrow or 'h' will
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reveal the source file names for each message and pressing again will
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show the full paths.
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When at the bottom of the log view, a summary line will be displayed on the
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right-hand-side to give you some more information about your logs, including:
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how long ago the last message was generated, the number of log files, the
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error rate, and how much time the logs cover. The error rate display shows
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the errors-per-minute over the last five minutes. A bar chart is also
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overlaid on the "Error rate" label to show the error rate over the past ten
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seconds. For example, if there have not been many errors in the past five
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minutes and there is a sudden spike, the bar chart will fill up completely.
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But, if there has been a steady stream of errors, then the chart will only
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partially fill based on the recent error frequency.
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Above and below the main body are status lines that display:
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* the current time;
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* the name of the file the top line was pulled from;
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* the log format for the top line;
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* the current view;
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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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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 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
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implemented using the readline library, so the usual set of keyboard
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shortcuts are available. Most commands and searches also support
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tab-completion.
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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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DEFAULT KEY BINDINGS
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====================
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Views
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-----
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? View/leave this help message.
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q Leave the current view or quit the program when in
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the log file view.
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Q Similar to 'q', except it will try to sync the top time
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between the current and former views. For example, when
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leaving the spectrogram view with 'Q', the top time in that
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view will be matched to the top time in the log view.
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TAB Toggle focusing on the filter editor or the main view.
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a/A Restore the view that was previously popped with 'q/Q'.
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The 'A' hotkey will try to match the top times between the
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two views.
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X Close the current text file or log file.
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Spatial Navigation
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------------------
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g/home Move to the top of the file.
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G/end Move to the end of the file. If the view is already
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at the end, it will move to the last line.
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space/pgdn Move down a page.
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b/bs/pgup Move up a page.
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j/cr/down-arrow Move down a line.
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k/up-arrow Move up a line.
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h/left-arrow Move to the left. In the log view, moving left will reveal
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the source log file names for each line. Pressing again
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will reveal the full path.
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l/right-arrow Move to the right.
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H/Shift+left Move to the left by a smaller increment.
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L/Shift+right Move to the right by a smaller increment.
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e/E Move to the next/previous error.
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w/W Move to the next/previous warning.
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n/N Move to the next/previous search hit. When pressed
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repeatedly within a short time, the view will move at
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least a full page at a time instead of moving to the
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next hit.
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f/F Move to the next/previous file. In the log view, this
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moves to the next line from a different file. In the
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text view, this rotates the view to the next file.
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>/< Move horizontally to the next/previous search hit.
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o/O Move forward/backward to the log message with a matching
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'operation ID' (opid) field.
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u/U Move forward/backward through any user bookmarks
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you have added using the 'm' key. This hotkey will
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also jump to the start of any log partitions that have
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been created with the 'partition-name' command.
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s/S Move to the next/previous "slow down" in the log message
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rate. A slow down is detected by measuring how quickly
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the message rate has changed over the previous several
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messages. For example, if one message is logged every
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second for five seconds and then the last message arrives
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five seconds later, the last message will be highlighted
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as a slow down.
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{/} Move to the previous/next location in history. Whenever
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you jump to a new location in the view, the location will
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be added to the history. The history is not updated when
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using only the arrow keys.
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Chronological Navigation
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------------------------
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d/D Move forward/backward 24 hours from the current
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position in the log file.
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1-6/Shift 1-6 Move to the next/previous n'th ten minute of the
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hour. For example, '4' would move to the first
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log line in the fortieth minute of the current
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hour in the log. And, '6' would move to the next
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hour boundary.
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7/8 Move to the previous/next minute.
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0/Shift 0 Move to the next/previous day boundary.
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r/R Move forward/backward based on the relative time that
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was last used with the 'goto' command. For example,
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executing ':goto a minute later' will move the log view
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forward a minute and then pressing 'r' will move it
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forward a minute again. Pressing 'R' will then move the
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view in the opposite direction, so backwards a minute.
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Bookmarks
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---------
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m Mark/unmark the line at the top of the display.
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The line will be highlighted with reverse video to
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indicate that it is a user bookmark. You can use
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the 'u' hotkey to iterate through marks you have
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added.
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M Mark/unmark all the lines between the top of the
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display and the last line marked/unmarked.
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J Mark/unmark the next line after the previously
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marked line.
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K Like 'J' except it toggles the mark on the
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previous line.
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c Copy the marked text to the X11 selection buffer or OS X
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clipboard.
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C Clear all marked lines.
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Display options
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---------------
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P Switch to/from the pretty-printed view of the log or text
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files currently displayed. In this view, structured data,
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such as XML, will be reformatted to make it easier to read.
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t Switch to/from the text file view. The text file view is
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for any files that are not recognized as log files.
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= Pause/unpause loading of new file data.
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Ctrl-L (Lo-fi mode) Exit screen-mode and write the
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displayed log lines in plain text to the terminal
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until a key is pressed. Useful for copying long lines
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from the terminal without picking up any of the extra
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decorations.
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T Toggle the display of the "elapsed time" column that shows
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the time elapsed since the beginning of the logs or the
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offset from the previous bookmark. Sharp changes in the
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message rate are highlighted by coloring the separator
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between the time column and the log message. A red
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highlight means the message rate has slowed down and green
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means it has sped up. You can use the "s/S" hotkeys to
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scan through the slow downs.
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i View/leave a histogram of the log messages over
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time. The histogram counts the number of
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displayed log lines for each bucket of time. The
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bars are layed out horizontally with colored
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segments representing the different log levels.
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You can use the 'z' hotkey to change the size of
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the time buckets (e.g. ten minutes, one hour, one
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day).
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I Switch between the log and histogram views while
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keeping the time displayed at the top of each view
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in sync. For example, if the top line in the log
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view is "11:40", hitting 'I' will switch to the
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histogram view and scrolled to display "11:00" at
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the top (if the zoom level is hours).
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z/Shift Z Zoom in or out one step in the histogram view.
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v Switch to/from the SQL result view.
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V Switch between the log and SQL result views while
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keeping the top line number in the log view in
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sync with the log_line column in the SQL view.
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For example, doing a query that selects for
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"log_idle_msecs" and "log_line", you can move the
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top of the SQL view to a line and hit 'V' to switch
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to the log view and move to the line number that was
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selected in the "log_line" column. If there is no
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"log_line" column, lnav will find the first column with
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a timestamp and move to corresponding time in the log
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view.
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TAB/Shift+TAB In the SQL result view, cycle through the columns that
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are graphed. Initially, all number values are displayed
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in a stacked graph. Pressing TAB will change the display
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to only graph the first column. Repeatedly pressing TAB
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will cycle through the columns until they are all graphed
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again.
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p In the log view: enable or disable the display of the
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fields that the log message parser knows about or has
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discovered. This overlay is temporarily enabled when the
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semicolon key (;) is pressed so that it is easier to write
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queries.
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In the DB view: enable or disable the display of values
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in columns containing JSON-encoded values in the top row.
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The overlay will display the JSON-Pointer reference and
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value for all fields in the JSON data.
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CTRL-W Toggle word-wrapping.
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CTRL-P Show/hide the data preview panel that may be opened when
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entering commands or SQL queries.
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CTRL-F Toggle the enabled/disabled state of all filters in the
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current view.
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x Toggle the hiding of log message fields. The hidden fields
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will be replaced with three bullets and highlighted in
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yellow.
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CTRL-X Toggle the cursor mode. Allows moving the selected line
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instead of keeping it fixed at the top of the current
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screen.
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F2 Toggle mouse support.
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Query
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-----
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/<regexp> Start a search for the given regular expression.
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The search is live, so when there is a pause in
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typing, the currently running search will be
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canceled and a new one started. The first ten lines
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that match the search will be displayed in the preview
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window at the bottom of the view. History is
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maintained for your searches so you can rerun them
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easily. Words that are currently displayed are also
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available for tab-completion, so you can easily
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search for values without needing to copy-and-paste
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the string. If there is an error encountered while
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trying to interpret the expression, the error will
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be displayed in red on the status line. While the
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search is active, the 'hits' field in the status
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line will be green, when finished it will turn
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back to black.
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Note: The regular expression format used by is PCRE
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(Perl-Compatible Regular Expressions). For example,
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if you wanted to search for ethernet device names,
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regardless of their ID number, you can type:
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eth\\d+
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You can find more information about Perl regular
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expressions at:
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http://perldoc.perl.org/perlre.html
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If the search string is not valid PCRE, a search
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is done for the exact string instead of doing a
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regex search.
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:<command> Execute an internal command. The commands are
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listed below. History is also supported in this
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context as well as tab-completion for commands and
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some arguments. The result of the command
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replaces the command you typed.
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;<sql> Execute an SQL query. Most supported log file
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formats provide a sqlite virtual table backend
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that can be used in queries. See the SQL section
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below for more information.
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|<script> [arg1 .. argN]
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Execute an lnav script contained in a format directory
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(e.g. \~/.lnav/formats/default). The script can contain
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lines starting with ':', ';', or '|' to execute commands,
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SQL queries or execute other files in lnav. Any values
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after the script name are treated as arguments can be
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referenced in the script using '\$1', '\$2', and so on, like
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in a shell script.
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CTRL+], ESCAPE Abort command-line entry started with '/', ':', ';', or '|'.
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Session
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-------
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CTRL-R Reset the session state. This will save the current
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session state (filters, highlights) and then reset the
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state to the factory default.
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Filter Editor
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-------------
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The following hotkeys are only available when the focus is on the filter
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editor. You can change the focus by pressing TAB.
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q Switch the focus back to the main view.
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j/down-arrow Select the next filter.
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k/up-arrow Select the previous filter.
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o Create a new "out" filter.
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i Create a new "in" filter .
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SPACE Toggle the enabled/disabled state of the currently
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selected filter.
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t Toggle the type of filter between "in" and "out".
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ENTER Edit the selected filter.
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D Delete the selected filter.
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MOUSE SUPPORT (experimental)
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============================
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If you are using Xterm, or a compatible terminal, you can use the mouse to
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mark lines of text and move the view by grabbing the scrollbar.
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NOTE: You need to manually enable this feature by setting the LNAV_EXP
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environment variable to "mouse". F2 toggles mouse support.
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COMMANDS
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========
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help Switch to this help text view.
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adjust-log-time <date|relative-time>
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Change the time of the top log line to the given time or
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adjusted by the relative time. All other log lines in the
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same file will also be adjusted using the same offset.
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After the adjustment, the displayed timestamp will be
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rewritten to the new time and highlighted with a magenta
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color.
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This command is useful for lining up log files that
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have timestamps from different machines.
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unix-time <secs-or-date>
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Convert a unix-timestamp in seconds to a
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human-readable form or vice-versa.
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BEWARE OF TIMEZONE DIFFERENCES.
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current-time Print the current time in human-readable form and
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as a unix-timestamp.
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|
|
goto <line#|N%|abs-time|relative-time>
|
|
Go to the given line number, N percent into the
|
|
file, or the given timestamp in the log view. If the
|
|
line number is negative, it is considered an offset
|
|
from the last line. Relative time values, like
|
|
'a minute ago', 'an hour later', and many other formats
|
|
are supported. When using a relative time, the 'r/R'
|
|
hotkeys can be used to move the same amount again or in
|
|
the same amount in the opposite direction.
|
|
|
|
relative-goto <line#|N%>
|
|
Move the current view up or down by the given amount.
|
|
|
|
comment <message>
|
|
Add a comment to the top line in the log view. The
|
|
comment will be saved in the session and will be available
|
|
the next time the file is loaded. Searches will also scan
|
|
the comment for any matches.
|
|
|
|
clear-comment Clear the comment that is attached to the top line in the
|
|
log view.
|
|
|
|
tag <tag1> [<tag2> [... <tagN>]]
|
|
Attach a tag to the top line in the log view. The tags are
|
|
prefixed with a '#', if they don't have one already. And,
|
|
like comments, they are saved in the session and
|
|
searchable.
|
|
|
|
untag <tag1> [<tag2> [... <tagN>]]
|
|
Detach a tag from the top line in the log view.
|
|
|
|
delete-tags <tag1> [<tag2> [... <tagN>]]
|
|
Detach the tags from all log lines.
|
|
|
|
next-mark error|warning|search|user|file|meta
|
|
Move to the next bookmark of the given type in the
|
|
current view.
|
|
|
|
prev-mark error|warning|search|user|file|meta
|
|
Move to the previous bookmark of the given type in the
|
|
current view.
|
|
|
|
hide-lines-before <abs-time|relative-time>
|
|
Hide lines that are before the given time. The given
|
|
time can be absolute (e.g. 2015-10-11)
|
|
The hidden lines can be shown again with the
|
|
'show-lines-before-and-after' command.
|
|
|
|
hide-lines-after <abs-time|relative-time>
|
|
Hide lines that are after the given time. The time can
|
|
The hidden lines can be shown again with the
|
|
'show-lines-before-and-after' command.
|
|
|
|
show-lines-before-and-after
|
|
Show lines that were hidden by the 'hide-lines' commands.
|
|
|
|
hide-unmarked-lines
|
|
Hide lines that have not been bookmarked.
|
|
|
|
show-unmarked-lines
|
|
Show lines that have not been bookmarked.
|
|
|
|
hide-fields <field-name> [<field-name2> ... <field-nameN>]
|
|
Hide large log message fields by replacing them with an
|
|
ellipsis. You can quickly switching between showing and
|
|
hiding hidden fields using the 'x' hotkey.
|
|
|
|
show-fields <field-name> [<field-name2> ... <field-nameN>]
|
|
Show log messages fields that were previously hidden with
|
|
the ':hide-fields' command.
|
|
|
|
highlight <regex> Highlight strings that match the given regular
|
|
expression.
|
|
|
|
clear-highlight <regex>
|
|
Clear an existing highlight created with the 'highlight'
|
|
command.
|
|
|
|
filter-in <regex> Only display lines that match the given regular
|
|
expression. This command can be used multiple
|
|
times to add more lines to the display. The number
|
|
of lines that are filtered out will be shown in the
|
|
bottom status bar as 'Not Shown'. Note that filtering
|
|
only works in the log and plain text views. There is also
|
|
a limit of 32 filters per-view at any one time.
|
|
|
|
filter-out <regex>
|
|
Do not display lines that match the given regular
|
|
expression. This command can be used multiple
|
|
times to remove more lines from the display. If a
|
|
'filter-in' expression is also active, it takes
|
|
priority and the filter-out will remove lines that
|
|
were matched by the 'filter-in'. The number
|
|
of lines that are filtered out will be shown in the
|
|
bottom status bar as 'Not Shown'. Note that filtering
|
|
only works in the log and plain text views. There is also
|
|
a limit of 32 filters per-view at any one time. While
|
|
entering the regular expression at the command-prompt, the
|
|
matches in the current text view will be highlighted in red
|
|
after a short delay.
|
|
|
|
disable-filter <regex>
|
|
Disable an active 'filter-in' or 'filter-out'
|
|
expression.
|
|
|
|
enable-filter <regex>
|
|
Enable a inactive 'filter-in' or 'filter-out'
|
|
expression.
|
|
|
|
delete-filter <regex>
|
|
Permanently delete a filter.
|
|
|
|
set-min-log-level <level>
|
|
Set the minimum level to display in the log view.
|
|
You can use TAB to view the possible values.
|
|
|
|
disable-word-wrap Disable word wrapping in the log and text file views.
|
|
enable-word-wrap Enable word wrapping in the log and text file views.
|
|
|
|
open <filename>[:<line>]
|
|
Open the given file within lnav and, if it is a
|
|
text file, switch to the text view and jump to
|
|
the given line number.
|
|
|
|
close Close the current text file or log file. You can also
|
|
close the current file by pressing 'X'.
|
|
|
|
spectrogram <field-name>
|
|
Generate a spectrogram for a numeric log message field or
|
|
SQL result column. The spectrogram view displays the range
|
|
of possible values of the field on the horizontal axis and
|
|
time on the vertical axis. The horizontal axis is split
|
|
into buckets where each bucket counts how many log messages
|
|
contained the field with a value in that range. The buckets
|
|
are colored based on the count in the bucket: green means
|
|
low, yellow means medium, and red means high. The exact
|
|
ranges for the colors is computed automatically and
|
|
displayed in the middle of the top line of the view. The
|
|
minimum and maximum values for the field are displayed in
|
|
the top left and right sides of the view, respectively.
|
|
|
|
append-to <file> Append any marked lines to the given file.
|
|
|
|
write-to <file> Write any marked lines to the given file. Use '-' to
|
|
write the lines to the terminal.
|
|
|
|
write-csv-to <file>
|
|
Write the results of a SQL query to a CSV-formatted file.
|
|
When running in non-interactive mode, a dash can be used
|
|
to write to standard out. Use '-' to write the data to
|
|
the terminal.
|
|
|
|
write-json-to <file>
|
|
Write the results of a SQL query to a JSON-formatted file.
|
|
The contents of the file will be an array of objects with
|
|
each column in the query being a field in the objects.
|
|
When running in non-interactive mode, a dash can be used
|
|
to write to standard out. Use '-' to write the data to
|
|
the terminal.
|
|
|
|
write-jsonlines-to <file>
|
|
Write the results of a SQL query to a JSON-Lines-formatted
|
|
file. Each row in the result set will be a single line of
|
|
JSON in the output and each column will be a property in
|
|
that object. Use '-' to write the data to the terminal.
|
|
|
|
pipe-to <shell-cmd>
|
|
Send the currently marked lines to the given shell command
|
|
for processing and open the resulting file for viewing.
|
|
|
|
pipe-line-to <shell-cmd>
|
|
Send the top log message to the given shell command
|
|
for processing and open the resulting file for viewing.
|
|
The known and discovered message fields are available as
|
|
environment variables. For example, log_procname in a
|
|
syslog message.
|
|
|
|
redirect-to <path>
|
|
If a path is given, all output from commands, like
|
|
":echo" and when writing to stdout (e.g. :write-to -), will
|
|
be sent to the given file. If no path is specified, the
|
|
current redirect will be cleared and output will be
|
|
captured as it was before the redirect was done.
|
|
|
|
session <cmd> Add the given command to the session file
|
|
(\~/.lnav/session). Any commands listed in the session file
|
|
are executed on startup. Only the highlight, word-wrap, and
|
|
filter-related commands can be added to the session file.
|
|
|
|
create-logline-table <table-name>
|
|
Create an SQL table using the top line of the log view
|
|
as a template. See the "SQL QUERIES" and "DYNAMIC LOG
|
|
LINE TABLE" sections below for more information.
|
|
|
|
delete-logline-table <table-name>
|
|
Delete an SQL table created by the 'create-logline-table'
|
|
command.
|
|
|
|
create-search-table <table-name> [<regex>]
|
|
Create an SQL table that extracts information from logs
|
|
using the provided regular expression or the last search
|
|
that was done. Any captures in the expression will be
|
|
used as columns in the SQL table. If the capture is named,
|
|
that name will be used as the column name, otherwise the
|
|
column name will be of the form 'col_N'.
|
|
|
|
delete-search-table <table-name>
|
|
Delete a table that was created with create-search-table.
|
|
|
|
switch-to-view <view-name>
|
|
Switch the display to the given view, which can be one of:
|
|
help, log, text, histogram, db, and schema.
|
|
|
|
zoom-to <zoom-level>
|
|
Change the histogram zoom level to the given value, which
|
|
can be one of: day, 4-hour, hour, 10-minute, minute
|
|
|
|
redraw Force redraw the window.
|
|
|
|
partition-name <name>
|
|
Mark the top line in the log view as the start of a new
|
|
partition with the given name. The current partition name
|
|
will be reflected in the top status bar next to the current
|
|
time as well as being available in the 'log_part' column
|
|
of the SQL log tables. Partitions can be used to make it
|
|
easier to query subsections of log messages.
|
|
|
|
clear-partition
|
|
Clear the partition the top line is a part of.
|
|
|
|
echo [-n] <msg> Display the given message. Useful for scripts to message
|
|
the user. The '-n' option leaves out the new line at the
|
|
end of the message.
|
|
|
|
eval <cmd|query|file>
|
|
Execute the given command, query, or file after doing
|
|
environment variable substitution. The argument to this
|
|
command should start with a ':', ';', or '|' signify the
|
|
type of action to perform (command, SQL query, execute
|
|
script).
|
|
|
|
pt-min-time [<date>|<relative-time>]
|
|
Set/get the minimum time range for any papertrail queries.
|
|
Absolute or relative time values can be specified.
|
|
|
|
pt-max-time [<date>|<relative-time>]
|
|
Set/get the maximum time range for any papertrail queries.
|
|
Absolute or relative time values can be specified.
|
|
|
|
config <option> [value]
|
|
Set/get the value of a configuration option.
|
|
|
|
reset-config <option>
|
|
Reset a configuration option to the default value. Use
|
|
'*' to reset all options.
|
|
|
|
quit Quit lnav.
|
|
|
|
SQL QUERIES (experimental)
|
|
===========
|
|
|
|
Lnav has support for performing SQL queries on log files using the
|
|
Sqlite3 "virtual" table feature. For all supported log file types,
|
|
lnav will create tables that can be queried using the subset of SQL
|
|
that is supported by Sqlite3. For example, to get the top ten URLs
|
|
being accessed in any loaded Apache log files, you can execute:
|
|
|
|
;select cs_uri_stem, count(*) as total from access_log
|
|
group by cs_uri_stem order by total desc limit 10;
|
|
|
|
The query result view shows the results and graphs any numeric
|
|
values found in the result, much like the histogram view.
|
|
|
|
The builtin set of log tables are listed below. Note that only the
|
|
log messages that match a particular format can be queried by a
|
|
particular table. You can find the file format and table name for
|
|
the top log message by looking in the upper right hand corner of the
|
|
log file view.
|
|
|
|
Some commonly used format tables are:
|
|
|
|
access_log Apache common access log format
|
|
syslog_log Syslog format
|
|
strace_log Strace log format
|
|
generic_log 'Generic' log format. This table contains messages
|
|
from files that have a very simple format with a
|
|
leading timestamp followed by the message.
|
|
|
|
NOTE: You can get a dump of the schema for the internal tables, and
|
|
any attached databases, by running the '.schema' SQL command.
|
|
|
|
The columns available for the top log line in the view will
|
|
automatically be displayed after pressing the semicolon (;) key.
|
|
All log tables contain at least the following columns:
|
|
|
|
log_line The line number in the file, starting at zero.
|
|
log_part The name of the partition. You can change this
|
|
column using an UPDATE SQL statement or with the
|
|
'partition-name' command. After a value is set,
|
|
the following log messages will have the same
|
|
partition name up until another name is set.
|
|
log_time The time of the log entry.
|
|
log_idle_msecs The amount of time, in milliseconds, between the
|
|
current log message and the previous one.
|
|
log_level The log level (e.g. info, error, etc...).
|
|
log_mark The bookmark status for the line. This column
|
|
can be written to using an UPDATE query.
|
|
log_path The full path to the file.
|
|
log_text The raw line of text. Note that this column is
|
|
not included in the result of a 'select *', but
|
|
it does exist.
|
|
|
|
The following tables include the basic columns as listed above and
|
|
include a few more columns since the log file format is more
|
|
structured.
|
|
|
|
syslog_log
|
|
|
|
log_hostname The hostname the message was received from.
|
|
log_procname The name of the process that sent the message.
|
|
log_pid The process ID of the process that sent the message.
|
|
|
|
access_log (The column names are the same as those in the
|
|
Microsoft LogParser tool.)
|
|
|
|
c_ip The client IP address.
|
|
cs_username The client user name.
|
|
cs_method The HTTP method.
|
|
cs_uri_stem The stem portion of the URI.
|
|
cs_uri_query The query portion of the URI.
|
|
cs_version The HTTP version string.
|
|
sc_status The status number returned to the client.
|
|
sc_bytes The number of bytes sent to the client.
|
|
cs_referrer The URL of the referring page.
|
|
cs_user_agent The user agent string.
|
|
|
|
strace_log (Currently, you need to run strace with the
|
|
"-tt -T" options so there are timestamps for
|
|
each function call.)
|
|
|
|
funcname The name of the syscall.
|
|
result The result code.
|
|
duration The amount of time spent in the syscall.
|
|
arg0 - arg9 The arguments passed to the syscall.
|
|
|
|
These tables are created dynamically and not stored in memory or on
|
|
disk. If you would like to persist some information from the tables,
|
|
you can attach another database and create tables in that database.
|
|
For example, if you wanted to save the results from the earlier
|
|
example of a top ten query into the "/tmp/topten.db" file, you can do:
|
|
|
|
;attach database "/tmp/topten.db" as topten;
|
|
;create table topten.foo as select cs_uri_stem, count(*) as total
|
|
from access_log group by cs_uri_stem order by total desc
|
|
limit 10;
|
|
|
|
|
|
DYNAMIC LOG LINE TABLE (experimental)
|
|
======================
|
|
|
|
(NOTE: This feature is still very new and not completely reliable yet,
|
|
use with care.)
|
|
|
|
For log formats that lack message structure, lnav can parse the log
|
|
message and attempt to extract any data fields that it finds. This
|
|
feature is available through the "logline" log table. This table is
|
|
dynamically created and defined based on the message at the top of
|
|
the log view. For example, given the following log message from "sudo",
|
|
lnav will create the "logline" table with columns for "TTY", "PWD",
|
|
"USER", and "COMMAND":
|
|
|
|
May 24 06:48:38 Tim-Stacks-iMac.local sudo[76387]: stack : TTY=ttys003 ;
|
|
PWD=/Users/stack/github/lbuild ; USER=root ;
|
|
COMMAND=/bin/echo Hello, World!
|
|
|
|
Queries executed against this table will then only return results for
|
|
other log messages that have the same format. So, if you were to
|
|
execute the following query while viewing the above line, you might
|
|
get the following results:
|
|
|
|
;select USER,COMMAND from logline;
|
|
|
|
USER | COMMAND
|
|
---- | -------------------------
|
|
root | /bin/echo Hello, World!
|
|
mal | /bin/echo Goodbye, World!
|
|
|
|
|
|
The log parser works by examining each message for key/value pairs
|
|
separated by an equal sign (=) or a colon (:). For example, in the
|
|
previous example of a "sudo" message, the parser sees the "USER=root"
|
|
string as a pair where the key is "USER" and the value is "root".
|
|
If no pairs can be found, then anything that looks like a value is
|
|
extracted and assigned a numbered column. For example, the following
|
|
line is from "dhcpd":
|
|
|
|
Sep 16 22:35:57 drill dhcpd: DHCPDISCOVER from 00:16:ce:54:4e:f3 via hme3
|
|
|
|
In this case, the lnav parser recognizes that "DHCPDISCOVER", the MAC
|
|
address and the "hme3" device name are values and not normal words. So,
|
|
it builds a table with three columns for each of these values. The
|
|
regular words in the message, like "from" and "via", are then used to
|
|
find other messages with a similar format.
|
|
|
|
If you would like to execute queries against log messages of different
|
|
formats at the same time, you can use the 'create-logline-table' command
|
|
to permanently create a table using the top line of the log view as a
|
|
template.
|
|
|
|
|
|
OTHER SQL FEATURES
|
|
==================
|
|
|
|
Environment variables can be used in SQL statements by prefixing the
|
|
variable name with a dollar-sign (\$). For example, to read the value of
|
|
the HOME variable, you can do:
|
|
|
|
;SELECT \$HOME;
|
|
|
|
To select the syslog messages that have a hostname field that is equal
|
|
to the HOSTNAME variable:
|
|
|
|
;SELECT * FROM syslog_log WHERE log_hostname = \$HOSTNAME;
|
|
|
|
NOTE: Variable substitution is done for fields in the query and is not
|
|
a plain text substitution. For example, the following statement
|
|
WILL NOT WORK:
|
|
|
|
;SELECT * FROM \$TABLE_NAME; -- Syntax error
|
|
|
|
|
|
Access to lnav's environment variables is also available via the "environ"
|
|
table. The table has two columns (name, value) and can be read and written
|
|
to using SQL SELECT, INSERT, UPDATE, and DELETE statements. For example,
|
|
to set the "FOO" variable to the value "BAR":
|
|
|
|
;INSERT INTO environ SELECT 'FOO', 'BAR';
|
|
|
|
As a more complex example, you can set the variable "LAST" to the last
|
|
syslog line number by doing:
|
|
|
|
;INSERT INTO environ SELECT 'LAST', (SELECT max(log_line) FROM syslog_log);
|
|
|
|
A delete will unset the environment variable:
|
|
|
|
;DELETE FROM environ WHERE name='LAST';
|
|
|
|
The table allows you to easily use the results of a SQL query in lnav
|
|
commands, which is especially useful when scripting lnav.
|
|
|
|
|
|
PAPERTRAIL INTEGRATION
|
|
======================
|
|
|
|
Papertrail is a log management service with free and paid plans at:
|
|
|
|
http://papertrailapp.com
|
|
|
|
To configure lnav to communicate with the papertrail service, you will
|
|
need to set the PAPERTRAIL_API_TOKEN environment variable. You can
|
|
get your API token from your user profile, available here:
|
|
|
|
https://papertrailapp.com/user/edit
|
|
|
|
Searching papertrail using lnav can be done by prefixing the search terms
|
|
with "pt:" and passing the value as a file name. For example, to search
|
|
for log messages with the string 'Critical Error' when starting lnav you
|
|
can do the following:
|
|
|
|
\$ setenv PAPERTRAIL_API_TOKEN xxxxxxxxx
|
|
\$ lnav "pt:'Critical Error'"
|
|
|
|
If lnav is already started, you can use the ':open' command like so:
|
|
|
|
:open pt:'Critical Error'
|
|
|
|
If you just want to tail your logs in papertrail, you can pass an empty
|
|
search string (i.e. "pt:").
|
|
|
|
Only one papertrail search can be active at a time. So, if an ':open'
|
|
is done with a new query, the previous query will be closed first.
|
|
|
|
|
|
CONTACT
|
|
=======
|
|
|
|
For more information, visit the lnav website at:
|
|
|
|
http://lnav.org
|
|
|
|
For support questions, email:
|
|
|
|
lnav@googlegroups.com
|
|
|
|
|
|
REFERENCE
|
|
=========
|