Transfer only the changed parts of a single file

[Pete]

I'm looking for a way to only transfer the changed parts of a file between two computers. This would be especially useful when using a slower connection such as an FTP site.

For example, I have a mailbox file called JohnDoe.mbx that resides on a remote computer that is 1 MB. This first time that this file appears on the remote computer, I would transfer the entire file to my local computer. If John Doe then receives a new mail message to the mailbox that is only 1 KB, then during the next BC synchronization I don't want to transfer the entire file again, I just want to transfer the 1 KB worth of changes to the file since the last sync.

I'm not aware of this capability in BC, but wanted to ask these questions:

1) Is there any chance that BC might support such a thing in the future?

2) Regardless, does anyone know of any software on the market that would let me do this today?

Thanks in advance.

[Pete]

Here are two possible solutions:

RSync. This is a UNIX/GNU type program that's been ported to Windows. Although it sounded like it might do what I want, I didn't want to bother with such a program if there were already a native Windows application with a nice GUI.

PC Anywhere. I already owned this, and I realized that it has a file-transfer feature called SpeedSync that supposedly does what I want. I tested it in several ways this morning and it seems to work quite well so I've decided to use it.
Having chosen PC Anywhere (PCA) for the task, I want to be clear that it couldn't possibly replace BC. PCA's user interface is cumbersome and other than its SpeedSync technology, its file-synchronization features are definitely not its strong point. In fact, PCA doesn't even let you specify that you want to include subfolders. Instead, you have to manually specify every single folder that you want to sync. Ugh!

I've decided to take a two-step approach. First, I'll use PCA to sync the large files between the remote and local computers. Then, I'll use BC to sync the rest of the files.

It would be nice if BC supported this feature intrinsically without the need for other software.

[Craig]

This is on the wishlist.

If PC Anywhere has command line support, or if you wanted to try using RSync, you could try setting one of them up as a BC2 "Open With" application. It's wouldn't be quite as built-in as the native copy & sync functions, but it might make things a bit easier.