Question : How to monitor changes in file content?

Hi,

I need to write a simple(?) component that will monitor the changes being made to a text file and notify them to registered listeners.

I have a process which writes data to a text file in the following way:

Start
... //data
End
Start
...//data
End
...
etc

I want to monitor the file and get notified when certain lines are written (e.g. Start/End).

A quick google search yielded the FileSystemWatcher class but I don't think it fits since it only monitors file system events and not file content, but I could be wrong as I'm fairly new to C#/.NET.

Thanks for any help.

Answer : How to monitor changes in file content?

Something like this..  Then when the changed event fires look in the file for the changes.

You will probably need to keep counter for start and one for end then when the file changes read the file and compare the counts.


static void Main(string[] args)
        {
            FileSystemWatcher watch = new FileSystemWatcher();
            watch.Path = @"D:\tmp";

            watch.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;

            // Only watch text files.
            watch.Filter = "*.txt";

            watch.Changed += new FileSystemEventHandler(OnChanged);
            watch.Created += new FileSystemEventHandler(OnChanged);
            watch.Deleted += new FileSystemEventHandler(OnChanged);
            watch.Renamed += new RenamedEventHandler(OnRenamed);

            watch.EnableRaisingEvents = true;

            Console.ReadLine();
        }

        private static void OnChanged(object source, FileSystemEventArgs e)
        {
            // Specify what is done when a file is changed, created, or deleted.
            if(e.FullPath == @"D:\tmp\p.txt")
                Console.WriteLine("File: " + e.FullPath + " " + e.ChangeType);

        }

        private static void OnRenamed(object source, RenamedEventArgs e)
        {
            // Specify what is done when a file is renamed.
            if (e.FullPath == @"D:\tmp\p.txt")
                Console.WriteLine("File: {0} renamed to {1}", e.OldFullPath, e.FullPath);
        }