Filtering FileSystemWatcher Events By File Size

[rich_wenger]

Hi, I am attempting to create a service to watch particular directories for excessively large files being created. I've created a Created event handler with the following code: void fileSystemWatcher1_Created(object sender, FileSystemEventArgs e) { FileInfo fi = new FileInfo(e.FullPath); if (fi.Length > 524288000)// 500MB = 524288000 { smtpMessage.Body = "A file exceeding 500 MB has been created at " + e.FullPath.ToUpper(); Client.Send(smtpMessage); } } I drop files one at a time into the watched directory and I'll get an email alert for the first file but nothing for subsequent files? Any help greatly appreciated.

C. Richard Wenger System Administrator

[realJSOP]

How are you initializing the watcher?

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
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"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

[Dave Kreskowiak]

rich_wenger wrote:

FileInfo fi = new FileInfo(e.FullPath); if (fi.Length > 524288000)// 500MB = 524288000

This isn't going to work. When a file is created, it's length is always 0. Only when the application flushes it's writes to the file does the filesize increase, for which there is NO FSW event. Your code has to keep track of the files that are new, then occasionally check back with those files to get their current sizes, then you can do what's necessary.

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Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008

[rich_wenger]

This is what I have setup: this.fileSystemWatcher1.Path = directoryPath1; this.fileSystemWatcher1.IncludeSubdirectories = true; this.fileSystemWatcher1.Filter = "*.*"; this.fileSystemWatcher1.Created += new FileSystemEventHandler(fileSystemWatcher1_Created);

C. Richard Wenger System Administrator

[rich_wenger]

I think I understand what you are saying, I am just not certain why I am getting the first email alert?

C. Richard Wenger System Administrator

[realJSOP]

You haven't set a NotifyFilter, and you haven't turned on EnableRaisingEvents...

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

[rich_wenger]

Sorry, I've got EnableRaisingEvents = true in the OnStart method for the service. I'm not certain how I would code a NotifyFilter since none of them seem to relate to file size?

C. Richard Wenger System Administrator

[Dave Kreskowiak]

FSW events don't fire exactly when the actual event occurs. In your case, it appears that the system was doning something else, blocking your application, but still queueing up the Create event. By the time your Create handler got called, the file had attained the require size to trip the email.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008

[Dave Kreskowiak]

There are no file size filters in the FSW. The filter is just there so the FSW knows which events you want to check for. The FSW polls the filesystem, taking snapshot after snapshot of the monitored directies and their files Created and LastModified times. Then it compares the new snapshot with the old one, generating the required events based on the differences between the two snapshots, subject to the NotifyFilter specification.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008

[realJSOP]

Well, I see a NotifyFilters.Size - isn't that what you want? At the same time, it might be better to filter on NotifyFilters.LastWrite so that you only have to deal with one event when the file is closed. At that point, you see how big the file is, and act accordingly, but you only do it once per file. Much more efficient.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

[rich_wenger]

I looking over what you've said and I'm trying to see if there is a way I can leverage this to a useable outcome. As I read it the NotifyFilters.Size reports a CHANGE in file size and I'm not certain how I could use this in my application. The goal is to send email alerts only when files are copied into a directory over a predertimed size limit (if that helps).

C. Richard Wenger System Administrator

[realJSOP]

Then you want to set the LastWrite filter. That way, when the file is closed, you'll be notified, and you can check the size. If your goal is to determine the size of the file *before* it's written, I don't think that's possible.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001