Solved

Catching data written to file by another app

Posted on 1998-12-30
3
157 Views
Last Modified: 2013-11-20
I’m using an application that asks for a filename and then writes a large amount of data to that file over the course of a day.

I would like to intercept this data and send it to another file, as it is written (essentially, creating a up-to-the-minute backup).

(This is under Windows NT.)

I've used memory-mapped files (via MFC) to do this kind of thing in the past but, in this case, I don't have access to the source code of the "originating" app.
0
Comment
Question by:sberger
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 

Author Comment

by:sberger
ID: 1327006
Edited text of question
0
 

Author Comment

by:sberger
ID: 1327007
Edited text of question
0
 
LVL 86

Accepted Solution

by:
jkr earned 200 total points
ID: 1327008
It is possible by hooking the 'WriteFile()' API for the originating app and intercepting the data. This can be done by creating a DLL that is mapped into the address space of the process writing to the file (see injlib.exe 'ftp://ftp.microsoft.com/softlib/mslfiles/INJLIB.EXE') and MS Systems Jounal May '94 'Load Your 32-bit DLL into Another Process's Address Space Using INJLIB' at http://www.microsoft.com/msj') and patching the function tables so that the 'WriteFile()' API call is redirected to one of your functions before you pass it through to the original function.
Feel free to ask if you need an example on how to do that and i'll send you the code (way too much to post it here... ;-)
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
substring method in java 1 142
Hibernate methods 2 88
canBalance challenge 34 111
sumHeights2  challenge 7 140
If you use Adobe Reader X it is possible you can't open OLE PDF documents in the standard. The reason is the 'save box mode' in adobe reader X. Many people think the protected Mode of adobe reader x is only to stop the write access. But this fe…
Have you tried to learn about Unicode, UTF-8, and multibyte text encoding and all the articles are just too "academic" or too technical? This article aims to make the whole topic easy for just about anyone to understand.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

751 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question