C / C++ / MFC Discussion Boards

Selevercin16-Nov-02 8:55

16-Nov-02 8:55

Is it possible to create a hook for a MS DOS program? I wish to hook NT's net.send function that you can use under CMD (I assume it stands for command).

For those who are wondering, I wish to block out which computer sends the message. My school frowns on sending messages, and I wish for a little more impunity!

Thanks,

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

Re: Console Hook

Chris Richardson16-Nov-02 11:19

Chris Richardson

16-Nov-02 11:19

There is a way to hook API calls for all processes in the system. You must first write a DLL and get it loaded (possible using a global message hook) in all processes. Then, it's possible to hook functions using APIHijack, which can be found I think here on CodeProject. The function you will want to hook is called NetMessageBufferSend, located in NetApi32.dll, which is what the "net send" command uses I'm sure.

Chris Richardson

Programmers find all sorts of ingenious ways to screw ourselves over. - Tim Smith

Re: Console Hook

Chris Richardson16-Nov-02 11:28

Chris Richardson

16-Nov-02 11:28

Or maybe it would be easier just to write your own program which would call NetMessageBufferSend, and pass some bogus name for the "fromname" parameter.

Chris Richardson

Programmers find all sorts of ingenious ways to screw ourselves over. - Tim Smith

Re: Console Hook

Selevercin16-Nov-02 12:44

Selevercin

16-Nov-02 12:44

Cool, I didn't know about that function Smile | :)

Works for me! Do you know what the parameter ServerName needs? An IP address? Also, what is Msgname? I assume the par. buf is the actual message.

Thanks VERY much,

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

Re: Console Hook

Chris Richardson18-Nov-02 6:59

Chris Richardson

18-Nov-02 6:59

Unless you want the function to execute on some other machine (which the ServerName would be the name or IP address of), you can pass NULL for the ServerName parameter. Indeed, the parameter buf is the message.

Selevercin wrote:
Thanks VERY much

No problem Smile | :)

Chris Richardson

Programmers find all sorts of ingenious ways to screw ourselves over. - Tim Smith

Re: Console Hook

Selevercin18-Nov-02 10:46

Selevercin

18-Nov-02 10:46

Sorry, but one last question. For the second parameter (Send To) it wants a constant unsigned short pointer. I have no idea what to do for this. I feel like I should put in a string with the computer name of which I'm sending to. Any ideas?

Thanks again,

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

Re: Console Hook

Chris Richardson18-Nov-02 10:52

Chris Richardson

18-Nov-02 10:52

It's a wide character string specifying either the name of the computer to send to, or the IP address of the computer to send to. So, you could do something like this to send it to IP address 127.0.0.1 (your own computer):

NetMessageBufferSend( NULL,
                      L"127.0.0.1",
                      L"Bogus FromName",
                      (BYTE*)L"123",
                      6 );

The L character in front of the strings specifies that you want the string to be a wide character string. Note that the example isn't a real world example, it's just meant to show the simplest way to do it.

Chris Richardson

Programmers find all sorts of ingenious ways to screw ourselves over. - Tim Smith

Re: Console Hook

Selevercin18-Nov-02 11:51

Selevercin

18-Nov-02 11:51

Ok, first let me appologize for being stupid. I can't figure out how to get an edit box to input wide characters. Do I need to start out as a string, then convert it to wide characters?

Thanks, again I appologize for being stupid,

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

Re: Console Hook

Chris Richardson18-Nov-02 12:01

Chris Richardson

18-Nov-02 12:01

I edited this because it wasn't entirely accurate...

You don't have to apologize. Here's a sample of how to convert from a "TCHAR" string that the CString uses (which can be char or wchar_t), like you can get from the edit control, to a "whar_t" string, like the NetMessageBufferSend function expects:

// This would be the text we got from the edit:
CString a_sThisCameFromTheEditControl = "127.0.0.1";
// This will be the text we pass to NetMessageBufferSend.
wchar_t a_uszWillBePassedToTheFunction[128] = {0};

// Convert the text from char to wchar_t
MultiByteToWideChar( CP_ACP, 0, a_sThisCameFromTheEditControl, -1, a_uszWillBePassedToTheFunction, sizeof( a_uszWillBePassedToTheFunction ) );

I'm not sure what will happen if you do a UNICODE build of your application though...

Chris Richardson

Programmers find all sorts of ingenious ways to screw ourselves over. - Tim Smith

Re: Console Hook

Selevercin18-Nov-02 13:05

Selevercin

18-Nov-02 13:05

Very cool! It all compiles! I can't wait to try it out (I'm not on a network here at home).

Thanks very much,

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

named objects from service

Hugo Hallman16-Nov-02 7:59

Hugo Hallman

16-Nov-02 7:59

How do I open a named object (memory mapping) created in a service from a user session app?
prefixing with
"Global\" ?

Re: named objects from service

ian mariano16-Nov-02 9:29

ian mariano

16-Nov-02 9:29

See OpenFileMapping()[^]

If you're not using Terminal Services, as the above link states, then "Global\" would be ignored.

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano - http://www.ian-space.com/

Re: named objects from service

Daniel Lohmann17-Nov-02 5:53

Daniel Lohmann

17-Nov-02 5:53

ian mariano wrote:
If you're not using Terminal Services, as the above link states, then "Global\" would be ignored.

...unless you are running on NT4. There the global prefix would cause an error!

--

Daniel Lohmann

http://www.losoft.de
(Hey, this page is worth looking! You can find some free and handy NT tools there Big Grin | :-D

)

The alternate menu that is used when MDI children are present

S O S16-Nov-02 7:35

S O S

16-Nov-02 7:35

My menu works fine until I make a new child... then the menu changes to the 2nd one and I lose all changes to the menu.
How can I detect the change of menus to the one used with MDI children active, so I can update the 2nd menu?
Or is there a better way of dealing with this? Modify both menus at once when needed? If so then how? I didn't find any referenches to the 2nd one.

Changing the color of Frame Window & Menus in SDI app

m_usman16-Nov-02 7:20

m_usman

16-Nov-02 7:20

I m developing an SDI application derived from class CView in MFC. I have to change the color of whole window which includes Menus,Frame Window & Client Area. I am succeed in changing the color of client area of SDI & Toolbar, but I don't know that how can I change the colors of Frame Window & Menus.
Is there any way to change the colors of Frame Window & Menus.

awaiting for reply.

regards,
M. Usman Ghani Khan Sleepy | :zzz:

Re: Changing the color of Frame Window & Menus in SDI app

valikac16-Nov-02 10:43

valikac

16-Nov-02 10:43

One solution is to derive a class from CFrameWnd and paint the frame. The same concept works for menu.

Kuphryn

SetCursorPos and WM_MOUSEMOVE

mishgun16-Nov-02 6:09

mishgun

16-Nov-02 6:09

hello.

i have overriden WindowProc for CButton-derived control and handle WM_MOUSEMOVE message
in message handler i call ::SetCursorPos

all i want to know is: does ::SetCursorPos function send WM_MOUSEMOVE message or not?

thanks in advance

nobody is perfect

Re: SetCursorPos and WM_MOUSEMOVE

PJ Arends16-Nov-02 9:30

PJ Arends

16-Nov-02 9:30

AFIAK it sends the WM_MOUSEMOVE message to the window that contains the cursor's new position, but not to the window that contains the cursors old position.

CPUA 0x5041

Sonork 100.11743 Chicken Little

"So it can now be written in stone as a testament to humanities achievments "PJ did Pi at CP"." Colin Davies

Within you lies the power for good - Use it!

Re: SetCursorPos and WM_MOUSEMOVE

mishgun16-Nov-02 10:07

mishgun

16-Nov-02 10:07

what about SetCapture?

nobody is perfect

Re: SetCursorPos and WM_MOUSEMOVE

PJ Arends16-Nov-02 13:48

PJ Arends

16-Nov-02 13:48

What about it?

Re: SetCursorPos and WM_MOUSEMOVE

mishgun16-Nov-02 16:51

mishgun

16-Nov-02 16:51

i meant that if i SetCapture in CButton-derived control and in its WM_MOUSEMOVE message handler call ::SetCursorPos, will this control receive MW_MOUSEMOVE again?

nobody is perfect

Re: SetCursorPos and WM_MOUSEMOVE

PJ Arends16-Nov-02 19:04

PJ Arends

16-Nov-02 19:04

Yes, I believe so. Any window that has captured the mouse will receive all mouse messages.

SQL from a C program

CaesarCZ16-Nov-02 5:19

CaesarCZ

16-Nov-02 5:19

Hi,
I'd like to use SQL in my program... I don't care which implementation, but mySQL sequel would be fine. I just need it to work without the servert installed (on the user cup, that means it should work it out itself I guess). I tried one, but I quite didn't like it cause it didn't recognize types (which was explained to be advantage, which I may agree with, but I'm not happy about that). Anybody and suggestions

Thanks

Destroy session COM object.

devvvy16-Nov-02 4:43

devvvy

16-Nov-02 4:43

I wrote two asp pages: TestPage1.asp and ActionPage1.asp

TestPage1 is a simple page with a textbox and a submit button. It CreateObject and loads ActionPage1.asp.

In ActionPage1.asp, I destroy/dereference the server object:

Set Session("objSQLGen") = Nothing

The object gets destroyed as planned. However, if you click "Back" and submit again, you get an error trying to access an object that has been destroyed. So, the first block of ActionPage1.asp is to re-create the server object, if it hasnt already been created:

<% If Session("objSQLGen") = Nothing then
Set Session("objSQLGen") = Server.CreateObject("QueryGenAlpha.QueryGenerator")
End If
%>

However, I still have error saying that the object doesnt support the method or something.

I hope someone can see what's the error in this code...

(1) This is the opening page:

<%
Set Session("objSQLGen") = Server.CreateObject("QueryGenAlpha.QueryGenerator")
%>

<title>
Query Generator

RealTime7 Inc Query Generator

Enter txtParam:

(2) This is the action page:

THIS FIRST BLOCK HERE IS TO RE_CREATE THE SERVER OBJECT IF IT HASNT ALREADY BEEN CREATED.
<% If Session("objSQLGen") = Nothing then
Set Session("objSQLGen") = Server.CreateObject("QueryGenAlpha.QueryGenerator")
End If
%>

<title>
Generate SQL query statement.

<%
txtParam = Request.Form("txtParam")
txtSQL = Session("objSQLGen").GenQuery(txtParam)
Response.Write(txtSQL)
%>
<% Set Session("objSQLGen") = Nothing %>

(3) And the error that I'm getting is:

Error Type:
Microsoft VBScript runtime (0x800A01B6)
Object doesn't support this property or method
/ActionPage1.asp, line 1

This is really weird. Very weird indeed.

Thanks.

norm

Re: Destroy session COM object.

Christian Graus16-Nov-02 11:01

Christian Graus

16-Nov-02 11:01

norm wrote:
If Session("objSQLGen") = Nothing then
Set Session("objSQLGen") = Server.CreateObject("QueryGenAlpha.QueryGenerator")
End If

Why do you need to set it to nothing ?

Get rid of the 'if', as a starter. Also, why does it need to be in the session ? I'd just create the thing locally unless there is a real need for it to persist across pages, and my understanding is there isn't, you're just creating in one and destroying in the other.

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Last Visit: 31-Dec-99 18:00 Last Update: 8-Jun-24 21:41

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