How to monitor a folder for changes, and execute a command if it does, on Windows?

Question

There are similar questions for Linux and Mac, but I'm after a Windows solution here.

The problem is as follows: I want to write several (js) script files in a folder, and have a program monitor that folder for file changes and new files being added, and run a command whenever that happens (to compile them all into one single file).

The solution has to:

1. Monitor both file changes and new files being added, in a folder.
2. Run a command only if there is any change.

It would be best if it either is a built-in solution (like a JScript or VBscript snippet), or something that does not require installation.

Answer 1

There's a program called Belvedere that might do the trick.

http://ca.lifehacker.com/341950/belvedere-automates-your-self+cleaning-pc

It's a stand alone Windows app that runs in the background.

I've set it up to monitor my downloads folder for files with certain extensions with last modified dates of a day old. The files it finds, it deletes, however you could have it run an action instead.

Answer 2

I've had good success with an old program called Log Monitor. It's ancient, and long ago abandoned. But it serves the purpose pretty well.

http://www.freeware-guide.com/download/index2.html

Answer 3

I have created a simple utility for this purpose: https://github.com/benblamey/when_changed

usage: when_changed (file path) (command) (optional-parameters)

e.g. when_changed C:\somedir\foo.txt myapp.exe bar wibble 123

Answer 4

With .NET watchfolders this is really easy to code. I'm sure someone have done such a program.

Just found this gem for you http://www.guidingtech.com/9861/automate-folder-actions-windows-watch-4-folder/

Answer 5

I'm currently trying this app, which requires .NET, but looks like it does the job.

Answer 6

If you want to do a built-in solution using JScript or VBScript, then what you want to look for is file system monitoring using WMI event subscriptions. Basically you write the code to monitor a folder and preform actions when a change is detected such as:

• __InstanceCreationEvent
• __InstanceDeletionEvent
• __InstanceModificationEvent

...and your script runs on an interval watching for these events to occur. There are many resources, but here are some for VBScript and Powershell:

• CodeProject article
• Blog post
• Thread in microsoft.public.windows.server.scripting

Answer 7

This is such a common requirement that I'm surprised there's no convenient utility built into the OS itself.

Anyway as mentioned earlier I've used LogMonitor successfully in the past. However I found this blog post informative and am using Watch 4 Folder now.

Hopefully this helps you out.

Answer 8

Yet another tool: https://github.com/yankee42/java-file-change-watcher

Advantages: Platform independent (Java), small (10KB).

Disclaimer: I am the author

Answer 9

NirSoft has software for monitor files changes on Windows
FolderChangesView

FolderChangesView is a simple tool that monitors the folder or disk drive that you choose and lists every filename that is being modified, created, or deleted while the folder is being monitored. You can use FolderChangesView with any local disk drive or with a remote network share, as long as you have read permission to the selected folder.

you can download it for free from here
More Info

Answer 10

You can use http://jnotify.sourceforge.net/ which subscribes to os-specific filesystem monitoring events. The code is years old but still works (at least on the Windows Server 2013r2 I was testing it yesterday).

There is also github resurrection of jnotify project on https://github.com/redbooth/jnotify which does not offer standalone demo app but (according to commit logs) patches some bugs.

In java7 there should be some kind of inotify-like filesystem watch too, but I was not testing it yet.