lnav - Man Page

ncurses-based log file viewer

Examples (TL;DR)

View logs of a program, specifying log files, directories or URLs: lnav path/to/log_or_directory|url
View logs of a specific remote host (SSH passwordless login required): lnav ssh user@host1.example.com:/var/log/syslog.log
Validate the format of log files against the configuration and report any errors: lnav -C path/to/log_directory

The log file navigator, lnav, is an enhanced log file viewer that takes advantage of any semantic information that can be gleaned from the files being viewed, such as timestamps and log levels. Using this extra semantic information, lnav can do things like interleaving messages from different files, generate histograms of messages over time, and providing hotkeys for navigating through the file. It is hoped that these features will allow the user to quickly and efficiently zero in on problems.

Key Bindings

?: View/leave the online help text.
q: Quit the program.

Options

-h: Print help and exit
-H: Display the internal help text.
-n: Run without the curses UI. (headless mode)
-c cmd: Execute a command after the files have been loaded.
-f path: Execute the commands in the given file.
-I path: Add the given configuration directory to the search path.
-n: Do not open the default syslog file if no files are given.
-q: Quiet mode. Do not print the log messages after executing all of the commands.
-i: Install the given format files in the $HOME/.lnav/formats/installed directory and exit.
-u: Update formats installed from git repositories.
-C: Check the configuration and exit. The log format files will be loaded and checked. Any files given on the command-line will be loaded checked to make sure they match a log format.
-d file: Write debug messages to the given file.
-V: Print version information.
-r: Recursively load files from the given directories.
-R: Load older rotated log files as well.
-t: Prepend timestamps to the lines of data being read in on the standard input.