Solved

Finding whether the keyboard is used

Posted on 1998-09-10
11
170 Views
Last Modified: 2010-04-02
Hello.
I need to find whether a keyboard was used. I guess that what I should actually do is use a hook, to catch keyboard
messages. How do I do it?
What I'm actually trying to achieve is to decide whether the computer was used in the past 5 minutes. I thought I'd just look at the keyboard, and if it was pressed, than the computer was used (I also sense the mouse, but I know how to do this). Please help!
0
Comment
Question by:ShadowHawk071998
  • 4
  • 2
  • 2
  • +3
11 Comments
 
LVL 22

Expert Comment

by:nietod
Comment Utility
If this is windows, you can use a hook to intercept all the keyboard messages and record the time of each message, then note when the last message is more than 5 minutes old.  Take a look at SetWindowHook().

If this is not for windows, what OS is this for?
0
 
LVL 7

Expert Comment

by:psdavis
Comment Utility
I'd simply capture the WM_CHAR and/or the WM_KEYDOWN.  If you're using MFC, then override for the OnChar and/or the OnKeyDown methods.  Both are easy to use and will be very similar to the WM_MOUSEMOVE or the MouseMove method.

Phillip

0
 
LVL 22

Expert Comment

by:nietod
Comment Utility
Except an application only gets the char/key messages if it has the focus.  Thus, the user could be using the computer, but with this application in the background, and the application would think the computer is idle.
0
 
LVL 7

Expert Comment

by:psdavis
Comment Utility
Hmm... Good point.  I defer.  Thanks nietod.

Phillip
0
 
LVL 11

Expert Comment

by:alexo
Comment Utility
SetWindowHookEx() for Win32 platforms.

0
Maximize Your Threat Intelligence Reporting

Reporting is one of the most important and least talked about aspects of a world-class threat intelligence program. Here’s how to do it right.

 
LVL 2

Expert Comment

by:duneram
Comment Utility
I have a full proof solution that works on all windows platforms  but its worth way more than 100 points.  It took about 3 months to develop and lots of hard work using softice to figure out how ms windows works.

An alternative is the keyboard hook method mentioned before.  it would do a fair job.
0
 
LVL 11

Expert Comment

by:alexo
Comment Utility
>> I have a full proof solution that works on all windows platforms  but its worth way more than 100 points.

Duneram, most of us are here because we want to help and share knowledge.  If your solution is a trade secret you shouldn't even mention it here.  Otherwise, what difference does the number of "points" make?  They won't make your accountant any happier...
0
 
LVL 4

Expert Comment

by:pagladasu
Comment Utility
I agree with alexo. The points are really secondary - its the exchange of information and knowledge that matters.
0
 

Author Comment

by:ShadowHawk071998
Comment Utility
Thanks guyz.
I AM using windows, (The compiler is VC++) and I'm NOT using MFC. Can someone give a small example on how to use hooks? I haven't done it before.
0
 
LVL 11

Accepted Solution

by:
alexo earned 100 total points
Comment Utility
>> Can someone give a small example on how to use hooks? I haven't done it before.
You've come to the right person!

In order to set up a hook, call SetWindowsHookEx().  If you want the hook to be system-wide, put the hook code in a DLL and the hook handle in shared memory.

Confused?  See http://www.experts-exchange.com/Q.10063288 (5 points) or ask here.
0
 
LVL 11

Expert Comment

by:alexo
Comment Utility
And the autograder hits again!
Thank you so much for your consideration.
0

Featured Post

Highfive + Dolby Voice = No More Audio Complaints!

Poor audio quality is one of the top reasons people don’t use video conferencing. Get the crispest, clearest audio powered by Dolby Voice in every meeting. Highfive and Dolby Voice deliver the best video conferencing and audio experience for every meeting and every room.

Join & Write a Comment

When writing generic code, using template meta-programming techniques, it is sometimes useful to know if a type is convertible to another type. A good example of when this might be is if you are writing diagnostic instrumentation for code to generat…
This article will show you some of the more useful Standard Template Library (STL) algorithms through the use of working examples.  You will learn about how these algorithms fit into the STL architecture, how they work with STL containers, and why t…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

762 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

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now