lnav - Man Page
log file viewer for the terminal
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
Synopsis
lnav [options] [logfile1 logfile2 ...]
Description
The Logfile Navigator, lnav, is a log file viewer for the terminal. Given a set of files/directories, lnav will:
- decompress as needed;
- detect their format;
- merge the files together by time into a single view;
- tail the files, follow renames, find new files in directories;
- build an index of errors and warnings;
- pretty-print JSON-lines.
Key Bindings
- ?
View/leave the online help text.
- q
Quit the program.
Options
- -h
Print help and exit
- -H
Display the internal help text.
- -I path
Add the given configuration directory to the search path.
- -W
Print warnings related to lnav's configuration.
- -u
Update formats installed from git repositories.
- -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.
- -c cmd
Execute a command after the files have been loaded.
- -f path
Execute the commands in the given file.
- -e cmd
Execute a shell command-line.
- -t
Prepend timestamps to the lines of data being read in on the standard input.
- -n
Run without the curses UI. (headless mode)
- -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.
Optional arguments
- logfile1
The log files or directories to view. If a directory is given, all of the files in the directory will be loaded.
Management-Mode Options
- -i
Install the given format files in the $HOME/.lnav/formats/installed directory and exit.
- -m
Switch to the management command-line mode. This mode is used to work with lnav's configuration.
- -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.
Examples
To load and follow the syslog file:
lnav
To load all of the files in /var/log:
lnav /var/log
To watch the output of make with timestamps prepended:
make 2>&1 | lnav -t
Author
This manual page was written by Salvatore Bonaccorso <carnil@debian.org> for the Debian system (but may be used by others).