Windows program to monitor a log file for new lines and automatically display them as they are added to the file

Question

I have text file, like log.txt which constantly updates. I want some text editor which I can open on separate monitor to display this file. I want this text editor to "reload" text file from disk periodically (every N seconds) and to scroll down. What can you recommend?

Answer 1

If you prefer a GUI, you can use BareTail:

• free and paid versions available
• Windows
• Portable
• Like "tail -f" on Unix systems, but with many more features

• Tail multiple files

• Configurable highlighting

• Optimised real-time viewing engine
• View files of any size (> 2GB)
• Scroll to any point in the whole file instantly
• View files over a network
• Configurable line wrapping
• Configurable TAB expansion
• Configurable font, including spacing and offset to maximise use of screen space

Answer 2

If you just want to watch the log as it grows, look at the 'tail' utility in a command line window.

There's a port of some of the most common unix utilities to Windows at http://unxutils.sourceforge.net/ That package has the advantage that it requires nothing in the way of support - just drop the files somewhere in your path and they just work.

To use tail to watch a log file, open up a command line window (cmd.exe) and do:

tail -f <log.txt>

It'll just keep scrolling out the contents as the log file grows. Ctrl-C to stop.

Answer 3

You can use Windows PowerShell (free, included in Windows XP and later):

Get-Content test.txt -Wait

To change width:

---

Useful info left by ADTC as a comment: you should also change the Defaults if you want the width to be saved and restored on a new PowerShell instance, see screenshot below.

Answer 4

If you have Git (or GitHub) installed, you can find the tail utility available in Git Shell*. You can use it to follow any file:

tail -f logfile.log

Those experienced with Unix and Linux terminals will find this very familiar. Try tail --help for more information.

^{* Usually this is a modified instance of Windows PowerShell.}

You can also find the less utility installed with Git. As per the help text:

                         MOVING
F                    Forward forever; like "tail -f".

Note: I don't recommend installing Git just for this. But if you already have Git installed, there's no need to find third party tail or less utilities.

Answer 5

Log Expert is an open source alternative that is quite feature-rich. It has a so called tail mode to view the end of the file.

Some standard features:

• colorization of rows based on regex patterns
• search

Some original features:

• columnizers - split a log row into fields and interpret fields as date, time, or various other data types (you can write your own custom columnizer).
• time sync - you can sync two files, and jumping to a certain time in one of them will sync the other to the same (or close) time

This Youtube video contains a screencast of the tool.

Answer 6

Or you can use less, a free and open-source tool written and maintained by Mark Nudelman.

less +F log.txt

The advantage of less is that you can toggle it between being a file viewer (this disables automatic scrolling, and lets you search and scroll manually) and a log follower. Ctrl+C takes you into "less" mode (file viewer mode). And Shift+F returns you to follow mode.

Answer 7

During development I use Emacs text editor to monitor logs.

emacs-w32 from Cygwin is easier way to get Emacs and necessary environment.

Tail update to certain kinds of files can be added via:

(defun my/auto-revert-tail-mode-hook ()
  "Enable `auto-revert-tail-mode' for file in 'log' dir or ending on '.log'"
  (when (string-match "/logs?/\\|\\.\\(?:log\\|out\\)\\'"
                      (buffer-file-name (current-buffer)))
    (auto-revert-tail-mode 1)
    ))
(add-hook 'find-file-hook 'my/auto-revert-tail-mode-hook)

With TRAMP and ssh installed I can see updates in remote log files!

Answer 8

I wrote such a tool ("loxx") you can have a try at https://loxx.app/wp-content/uploads/loxx_setup.exe. It supports filtering, color highlighting, regex search, time stamps and much more also for running logs (used Baretail for a long long time but missed some features).