How to write File Synchronization Function with C#

Question

Hello! I would like to know how to write File Synchronization function use which Windows API? Does it File System API? How I can Hook File System API write File? The requirement of my File Synchronization function is listed on below: 1) Two different location servers e.g. Hong Kong and USA 2) When Hong Kong's server updated a file named as Record.xls the newly wrote data will be written into USA server's Record.xls. 3) The method is not use copy and paste just write the updated data into the other location's server Record.xls file. If anyone know how to write the File Synchronization function please give me reply asap. Thanks!

spgilmore · Answer

There is a filesystemwatcher component that will notify you when a file directory or other filesysem object has been modified. If you want to copy the file this will help. If you only want to write CHANGES you'll have to devise the scheme you're describing but it would be far easier (and probably faster) to copy the file instead of just applying changes even on a large file. To update just the changed bytes in a file you will have to have a backup of the previous version of the file to compare against and you'll have to build a patch file that contains the differences. Send this patch file to the other location and update the file with those changes.