lnav

lnav offers terminal tools to view, merge, follow, search, filter, and query log files.

About lnav

lnav is a log file viewer that runs in the terminal. It lets users merge, tail, search, filter, and query log files. The homepage states that it needs no server and no setup. Users point lnav at a directory, and it detects file formats automatically and unpacks compressed files as it reads them. It also provides online help and previews for operations, and a SQLite interface for querying log data.

The homepage says lnav can outperform standard terminal tools when processing log files. This claim is supported by a chart that compares CPU and memory usage on a 3.3GB access log, which was generated using lnav's SQLite interface. The homepage does not name the other tools compared or describe results beyond that single chart. An introductory video and documentation are linked from the homepage.

Key features

View, merge, tail, search, filter, and query log files in a terminal
Automatic detection of log file formats
Unpacks compressed files on the fly
Point at a directory to load its log files
SQLite interface for querying log data
Online help and previews for operations

Best for: Users who work with log files in a terminal and want to view, merge, search, filter, or query them without installing a server.

Good for

No server or setup is required, according to the homepage
Detects file formats automatically and unpacks compressed files as it reads them
Homepage reports a CPU and memory comparison showing lnav ahead of standard terminal tools on a 3.3GB access log