C / C++ / MFC

8-Dec-03 23:06

Hi,

I know it is possible to hook a function which is exported in a dll, but I was wondering if it is possible to hook a function in an exe?

thanx

Don't think you are, know you are...

jmkhael8-Dec-03 23:23

8-Dec-03 23:23

Do you have the source of that exe?

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

RicoH8-Dec-03 23:32

8-Dec-03 23:32

Yes, I do have the source of that exe.

What I would like to do is make some sort of program that hooks several functions of the specific exe so I can extract internal information.
We have lots of version of this exe and we can't put lots of debugging information in them...

Don't think you are, know you are...

jmkhael8-Dec-03 23:44

8-Dec-03 23:44

-You can export these functions from the exe
or
-Call a common function that is exported into the dll and giving you the amount of info you need

Or Make own your own debugging thread and check the CreateRemoteThread family API

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

RicoH8-Dec-03 23:50

8-Dec-03 23:50

The problem is that I can't modify the sources of the original exe. Frown | :(

That's why I was wondering if it is possible the hook an 'internal' function, given that you know the name of it (if this is even relevant).

Don't think you are, know you are...

jmkhael9-Dec-03 0:16

9-Dec-03 0:16

In fact it is, but its a delicate process.
Saying you have several versions of the exe, so a reverse engineering method (patching and calling a code from an exe) is somehow difficult or even not feasible if you dont want to modify the code

So a CreateRemoteThread is a better way to deal with this problem, with a Stack handling method in order to see what function is being called so you dump its parameters

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

RicoH9-Dec-03 0:19

9-Dec-03 0:19

I'll have a look at the CreateRemoteThread thingy...

Thanx

Don't think you are, know you are...

Alexander ^M.,9-Dec-03 4:58

Alexander ^M.,

9-Dec-03 4:58

everything is possible!
tell me what's ur software's purpose and i'll tell u how to do it.

Don't try it, just do it! Wink | ;-)

atoi problems

styve8-Dec-03 22:43

styve

8-Dec-03 22:43

Hi!

I'm have some problems with atoi. My simple program reading numbers from a file into a buffer. The numbers represent the time of the day with microseconds precision.

Ex. 124831123456
124831234567

Then will I subtract them but it will not work? Can someone help me?

int line;
int t, t1, t2;
char buffer[ROW][Buffer_Size];

ifstream inFile;
char inputFilename;

for(int k=0; k<20; k++){
inFile.getline(buffer[k], TIME_SIZE);
}

for(int x=1; x<20; x++){
t2 = atoi(buffer[x]);
t1 = atoi(buffer[x-1]);
t = t2 -t1;

cout << "t is equal to " <

Re: atoi problems

jmkhael8-Dec-03 22:49

8-Dec-03 22:49

124831123456 is too big to fit in a int
try atof and fill it into a float or check strtol

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: atoi problems

Ian Darling8-Dec-03 23:31

Ian Darling

8-Dec-03 23:31

Try using 64 bit integers to store those values (as they are bigger than a 32 bit integer can handle). The type is __int64 and the conversion function is called _atoi64.

--
Ian Darling
"The moral of the story is that with a contrived example, you can prove anything." - Joel Spolsky

A Stupid doubt????

Ilamparithi8-Dec-03 22:42

Ilamparithi

8-Dec-03 22:42

Hi,

What is the difference between BOOL and bool??

Best Regards,
A.Ilamparithi

Re: A Stupid doubt????

jmkhael8-Dec-03 22:51

8-Dec-03 22:51

This topic is already discussed.

Quick info:

BOOL is a int ( integer value from 0 to 65535 )
bool is a boolean ( true false )

but BOOL can be used as bool ( BOOL bBoolean = TRUE or BOOL bBoolean = FALSE )

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: A Stupid doubt????

RChin8-Dec-03 23:01

RChin

8-Dec-03 23:01

BOOL goes back to the days when bool was not part of the C++ standard.
It is typedef'ed as an int, where FALSE is 0.
bool, however is inherently c++. Although BOOL and bool may be used interchangeably, you should be very aware of the dangers involved in mixing these two types.
There were a few discussions about this on the lounge a while ago I think. There may be an FAQ article about this as well. Have a search on it. It is worth knowing.

I Dream of Absolute Zero

Re: A Stupid doubt????

Michael Pauli9-Dec-03 5:22

Michael Pauli

9-Dec-03 5:22

If I remember it corectly it's: "enum and #define" - bool is a enum and the classic BOOL is #define'd

Regards,
Michael Mogensen, mm it-consult dk.

><((((º> ·.¸¸.· ><((((º> ·.¸¸.· ><((((º>

Printing trouble

El'Cachubrey8-Dec-03 22:23

El'Cachubrey

8-Dec-03 22:23

Hi I create an application which able to print any documents.

This bit of my code

...
//Create printer DC m_prtDC
...
//All fine ,now create compatible DC (m_extDC)
//with one ,which has same size
...
//All fine, set neccessary font size and print text
//into m_extDC
...
//Now try to print this text

m_prtDC.StartDoc(LPCTSTR("MyDoc"));
m_prtDC.StartPage();
//Copy from dc, where allocated my text to printer dc
//2400 & 3600 my printer DC size
m_prtDC.BitBlt(0,0,2400,3600,&m_extDC,0,0,SRCCOPY);
m_prtDC.EndPage();
m_prtDC.EndDoc();

When my printed text (printed with TextOut() fun)not enought big all printed fine.But when m_extDC hold a lot of text ,printer wan't to printed one.I watch what priner are prepared to printing (respected sensor are flick), but from any time error sensor are switched on, and all halt.At that
all invoked routines returned sucessfull.

Where is my fault, and how i can to solve it.
Thank.

Re: Printing trouble

Roger Allen9-Dec-03 4:24

Roger Allen

9-Dec-03 4:24

BitBlt() is usually not supported or incorrectly supported on most printer drivers (DC). If your printing in MFC make use of the standard MFC printing architecture. If not, take alook at Chris Maunders article "Printing wiuthout the Doc/view architecture" in the printing section. Also my article "Printing tips n Tricks from the Trenches" should be of use.

Roger Allen - Sonork 100.10016
If your dead and reading this, then you have no life!

accessing the base class

satadru8-Dec-03 21:28

satadru

8-Dec-03 21:28

hi ,
i have a dialog based application having a class for example CDialog. in the on button click event iam loading another dialog as follows:
m_pModeless= new dlg;
Then after getting the safeHwnd :
m_pModeless->Create(......);

where dlg is the class of the new dialog and m_pModeless has been declared in the header file as dlg *m_pModeless.

Now i want to access the member variables from this child window to the main window i.e from one class to the other.

I'am a bit confused of how to go about it ... please help.
Thanking you.
Satadru.

Antti Keskinen8-Dec-03 21:49

Antti Keskinen

8-Dec-03 21:49

I assume you are attempting one of the following procedures:

1. Accessing the newly created dialog from the button click event
2. Accessing the class running the button event from the newly created dialog

For case #1, the answer is simple: you already have a pointer to the class, and it is properly initialized by using new. You can use this pointer to alter the data members as you see fit.

For case #2, you need to specify the calling class as the parent of the newly created dialog. For modeless dialog creation, the calling convention would be CDialog::Create( UINT uiTemplateID, CWnd* pParent ). Specifying the this keyword into the parent pointer would designate the calling class as the parent of the newly created modeless dialog.

Further in case #2, you can access the parent window by using GetParent method, which will return a pointer to the parent class's CWnd. Because you have derived from CDialog, and because CDialog is derived from CWnd, you can use the pointer returned by GetParent and cast it down to the appropriate class.

Understanding this, here is a code fragment, which will do the casting operation. Remember that if you put this casting operation into a function inside the newly created dialog, you must include the header file of the parent dialog into the implementation file. Otherwise the casting operation is unable to determine the type of the variable. In here, we assume that the parent class (which handles the button click), is called CParentDialog and the child dialog (newly created one) is called CChildDialog.

// In the beginning of the implementation, include the header of parent
#include "ParentDialog.h"<DIV>

...<DIV>

// Further down the road, a member function of CChildDialog, get the parent class and cast it down
CParentDialog* pParentDialog = DYNAMIC_DOWNCAST( CParentDialog, GetParent() );<DIV>

// Use the pointer to access data member/methods
pParentDialog->SomeMethod( someParams );
pParentDialog->SomeData = SomeValue;

This functionality comes directly from the way MFC is designed. Have a look at the inheritance map (hiearchy chart). In C++, it is always possible to cast a pointer from the base class to the derived class, and in MFC, the most useful operation is DYNAMIC_DOWNCAST, because it will verify that the casting operation is succesfull, or return NULL if it is not.

When you create new window classes (Windows, dialogs, controls), you always derive from an existing base class (CWnd, CDialog, CButton/CEdit etc). Thus, if you create a new CButton, the derivance chart would be CWnd->CButton->CYourButton. If this button was a parent of another control (unlikely, but possible), then you could use the GetParent method to return a pointer to the above-mentioned CWnd class. Then, a cast operation from CWnd -> CYourButton would be completely valid.

I hope this will help you now, and that my extended rambling furthered your understanding of the MFC framework Smile | :)

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.

satadru9-Dec-03 0:30

satadru

9-Dec-03 0:30

hi thanks for your help ;
but theres a problem:-
inspite of including the header file of the main dialog viz CMainDlg its still giving me an error saying:
'classCMainDlg': is not a member of 'CMainDlg'

Could you please tell me why is this happening. Cry | :((

thanking you,
Satadru

Antti Keskinen9-Dec-03 2:27

Antti Keskinen

9-Dec-03 2:27

What is this 'viz' ? "Which is" ?

The error you are describing is related to the CMainDlg itself. You are referring to a member classCMainDlg somewhere in your code, and this member is not declared in the header file of the class. See the header file of CMainDlg for details, especially check the line where the error is.

The case #2 I posted back in my previous message did not tell you to add any member to the parent (CMainDlg) class. If you added members there, then you have done something wrong yourself.

In conclusion: this error has nothing to do with the method I described. It is happening because a) you have done something wrong yourself or b) have not understood my description properly.

I would ask you to post the line where this error is happening and the context where it is in. I believe that it might be in the line where you create the modeless dialog box. Remember, that the 'this' pointer always points to the current object that is executing a method. For example, if you had an object of a class created, returning 'this' from a function would return the address of the object.

Check your code and post the line where the error is happening. You probably have just mistyped something.

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.