Catching Filesystem Events « Filesystem Events « Stream

The FileSystemWatcher class lets you monitor a directory and subdirectories for activity.

FileSystemWatcher has events that fire when files or subdirectories are created, modified, renamed, and deleted, as well as when their attributes change.

 
using System;
using System.IO;
using System.Linq;
using System.Text;

class Program
{
    static void Main() { Watch(@"c:\temp", "*.txt", true); }

    static void Watch(string path, string filter, bool includeSubDirs)
    {
        using (var watcher = new FileSystemWatcher(path, filter))
        {
            watcher.Created += FileCreatedChangedDeleted; 
            watcher.Changed += FileCreatedChangedDeleted; 
            watcher.Deleted += FileCreatedChangedDeleted; 
            watcher.Renamed += FileRenamed;
            watcher.Error += FileError;

            watcher.IncludeSubdirectories = includeSubDirs;
            watcher.EnableRaisingEvents = true;

            Console.WriteLine("Listening for events - press <enter> to end"); 
            Console.ReadLine();
        }
    }

    static void FileCreatedChangedDeleted(object o, FileSystemEventArgs e)
    {
        Console.WriteLine("File {0} has been {1}", e.FullPath, e.ChangeType);
    }

    static void FileRenamed(object o, RenamedEventArgs e)
    {
        Console.WriteLine("Renamed: {0}->{1}", e.OldFullPath, e.FullPath);
    }

    static void FileError(object o, ErrorEventArgs e)
    {
        Console.WriteLine("Error: " + e.GetException().Message);
    }

}