The Logfile Navigator, lnav for short, is a curses-based tool for viewing and analyzing log files. The value added by lnav over text viewers / editors is that it takes advantage of any semantic information that can be gleaned from the log file, 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.

The major features of lnav are:

• Support for the following log file formats:
  

  Syslog, Apache access log, strace, tcsh history, and generic log files with timestamps. The file format is automatically detected when the file is read in.

• Histogram view:
  

  Displays the number of log messages per bucket-of-time. Useful for getting an overview of what was happening over a long period of time.

• Filters:
  

  Display only lines that match or do not match a set of regular expressions. Useful for removing extraneous log lines that you are not interested in.

• “Live” operation:
  

  Searches are done as you type; new log lines are automatically loaded and searched as they are added; filters apply to lines as they are loaded; and, SQL queries are checked for correctness as you type.

• Automatic tailing:
  

  The log file view automatically scrolls down to follow new lines that are added to files. Simply scroll up to lock the view in place and then scroll down to the bottom to resume tailing.

• Time-of-day ordering of lines:
  

  The log lines from all the files are loaded and then sorted by time-of-day. Relieves you of having to manually line up log messages from different files.

• Syntax highlighting:
  

  Errors and warnings are colored in red and yellow, respectively. Highlights are also applied to: SQL keywords, XML tags, file and line numbers in Java backtraces, and quoted strings.

• Navigation:
  

  There are hotkeys for jumping to the next or previous error or warning and moving forward or backward by an amount of time.

• Use SQL to query logs:
  

  Each log file line is treated as a row in a database that can be queried using SQL. The columns that are available depend on logs file types being viewed.

• Command and search history:
  

  Your previously entered commands and searches are saved so you can access them between sessions.

• Compressed files:
  

  Compressed log files are automatically detected and uncompressed on the fly.

IMO you can scroll up/down/right/left the log file without resizing the window. And it also contains a proportionally sized scrollbar.

On color displays, the lines will be highlighted as follows:

• Errors will be colored in red;
• warnings will be yellow;
• boundaries between days will be underlined; and
• various color highlights will be applied to: SQL keywords, XML
• tags, file and line numbers in Java backtraces, and
• quoted strings.

You can view its powerful feature via this screenshot:

This is really powerful.

On the top of itself, you can see the current time, and an important feature is that it can display the number of warnings(W) and errors(E) and the name of the log file; At the bottom you can also notice log lines in time sorted order and highlighted.

For more information, please refer to its instructions.

Install(if you cannot find this in Fedora 18+, please enable update-testing channel if you want):