C / C++ / MFC

Encoding & Decoding Algorithm?

7-Feb-07 23:08

harshadha wrote:
Command line error D2022 : cannot open '..\cfront\cl_preprocess_options.txt'

Create a text file at one directory up, then down into cfront-directory, and name it cl_preprocess_options.txt

Thats the answer to yout question. It is probably only mildly helpful.

With a few wild guesses and completly unjustified assumptions, I would say that you did some mistake unzipping the source code you want to work at.

"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation."

-- Caius Petronius, Roman Consul, 66 A.D.

Andy Rama7-Feb-07 22:44

Andy Rama

7-Feb-07 22:44

I want to encode a 20 digit no ( may start with 0 ).
How to encode it?
Which algorithm should be used for Encoding & Decoding?

Encode for WHAT

jhwurmbach7-Feb-07 23:04

7-Feb-07 23:04

Aniket Salunkhe wrote:
How to encode it?

Encode for what exactly?

Just for exercise? Try implementing BASE64.

Re: Encode for WHAT

Andy Rama8-Feb-07 8:13

Andy Rama

8-Feb-07 8:13

jhwurmbach wrote:
Encode for what exactly?

I want it for Registering my Application on other Systems.

Through my Application I get a card key which is 20 digits long ( in System my Application is installed ). Using that no, I want to encode it so that application can work (OR Register ) only if valid encoded input is entered.

For Implementation I want a encoding & it's decoding [B]algorithm[/B].

Re: Encode for WHAT

jhwurmbach9-Feb-07 2:15

9-Feb-07 2:15

Aniket Salunkhe wrote:
For Implementation I want a encoding & it's decoding [B]algorithm[/B].

From your text I gather that it is some copy protection scheme? Unsure | :~

For this, I (not being a cryptography expert) would recommend to do hashing of the number and store only the hash.
This way, it is impossible to get a working number by guessing the algorithm you used and decrypting.

For validation, you would apply the hash-function to the number entered and compare the hash with the stored hash. Your program would start up only if both are the same.
Wikipedia[^] has a bunch of links to ready-to-run-implementations.

CListView Problem

joshiprashant7-Feb-07 21:54

joshiprashant

7-Feb-07 21:54

I have derived a class from CListView and place it in a splitter window. I'm facing a problem that, I'm getting an extra column in List View, in report style. For example, I have created list with only 3 columns but if i decrease their width, it automatically inserts an extra column.
How to solve this problem of extra column?

Re: CListView Problem

jhwurmbach7-Feb-07 22:41

Rearranging the Tool bar menus.

7-Feb-07 22:41

joshiprashant wrote:
I have created list with only 3 columns but if i decrease their width, it automatically inserts an extra column.

You decrease the width of the columns, yet the width of the splitter-pane (the space between the splitter bars) remains the same. And so does the list, as its size is tied to the size of the splitter pane.
What can the ListView do, other than showing blank space to the right of the columns?
When you can answer that question, we may be able to help you to implement it.

Re: CListView Problem

Mark Salsbery8-Feb-07 6:03

Mark Salsbery

8-Feb-07 6:03

If you respond to WM_SIZE messages and resize the last column using ListView_SetColumnWidth with
a cx value of LVSCW_AUTOSIZE_USEHEADER then the last column will always take up remaining space
so you don't see the empty "column" (as jhwurmbach described).

Mark

FAT 32 file system

harsha_12347-Feb-07 21:14

harsha_1234

7-Feb-07 21:14

Hi all,

i want to study internals of fat file system.
so for that purpose which book i should use as an reference book.
just what
"The design of unix operating system (Maurice J Bach)"
does to understand the unix file sysetm.
Is there any such book by which i would be able to understand the fat file system.
If anyone know's please tell me.

i want to create a file system driver for fat fs.

Thanks and regards
Harshal shete

Re: FAT 32 file system

joshiprashant7-Feb-07 23:37

joshiprashant

7-Feb-07 23:37

Hi,
Refer, NT File System Internal from OSR press.

Re: FAT 32 file system

harsha_12348-Feb-07 19:28

harsha_1234

8-Feb-07 19:28

Thanks i will definitely read that book

Thanks and regards
Harshal shete

Sameer_Thakur7-Feb-07 20:14

Sameer_Thakur

7-Feb-07 20:14

Hi all.

My application has large number of tool bar button. When I change the setting of my computer's resolution from 1024 X 768 to 800 X 600, some of the tool bar options becomes inaccessible.
I want to either change the tool bar buttons size depending upon the resolution or provide a scroll bar to access the tool bar buttons which are getting hidden behind the application’s frame window.

How I can do this?
Is there ant API available to do this?

Thanks

Sameer Thakur

Naveen7-Feb-07 21:33

Naveen

7-Feb-07 21:33

Sameer_Thakur wrote:
I want to either change the tool bar buttons size

You can use SetSizes function of CToolbar for this

nave

Sameer_Thakur7-Feb-07 21:47

Sameer_Thakur

7-Feb-07 21:47

Yes Nev
but how can I coordinate the size that I pass to SetSizes() function with the Screen Resolution?

Thanks

Sameer Thakur

Naveen7-Feb-07 22:19

Naveen

7-Feb-07 22:19

in the resolution of 1024 X 768 you know the width and height of the tool bar. change it to percentage of the screen height and width.

So when the resolution changes, u can set the new height and width of toolbar as that percentage of the screen height and width.

nave

compiler generated function

Mark Salsbery8-Feb-07 6:09

Mark Salsbery

8-Feb-07 6:09

You could use the TBSTYLE_WRAPABLE style on the toolbar. Letting the tolbar wrap buttons to
a new row isn't necessarily the way you want it to look though Smile | :)

sheetal_067-Feb-07 20:05

sheetal_06

7-Feb-07 20:05

When i am compiling the following code i am getting an error.

ERROR is:

error C2248: 'CObject::operator =' : cannot access private member declared in class 'CObject'"
see declaration of 'CObject::operator ='
see declaration of 'CObject'
This diagnostic occurred in the compiler generated function 'CPtrArray &CPtrArray::operator =(const CPtrArray &)'

Why the compiler is generating the function 'CPtrArray &CPtrArray::operator =(const CPtrArray &)'?

CPtrArray inherits CObject but it does not implement operator=
This error message is coming after conversion to .net..

class CPtrArray : public CObject
{
//does not implement operator=

}

class __declspec ( dllexport ) CCASObject : public CObject
{
public:
virtual void operator=( const CCADSObject& ){}
};

class CSpanLoad : public CCASObject
{
public:
void operator=( const CCASObject& );

private:
CPtrArray aPointArrays;
};

//spanload.cpp
void CSpanLoad::operator=( const CCASObject &src )
{

//....
}

//Import.cpp
int CImport::ReadLoadCategoryData()
{
CSpanLoad *pA3Ld,*pBDLd;
*pA3Ld = *pBDLd; //this assignment is giving error in VS2005.In VC6 it was not showing the error;
}

Thanks..

prasad_som7-Feb-07 21:18

prasad_som

7-Feb-07 21:18

sheetal_06 wrote:
void operator=( const CCASObject& );

How this operator is defined?
How you are using aPointArrays in your code ?

Prasad
Notifier using ATL | Operator new[],delete[][^]

sheetal_067-Feb-07 23:20

sheetal_06

7-Feb-07 23:20

Hi,

It is getting invoked when

*pA3Ld = *pBDLd;

is executed.And there only it is giving error.

//this is how it is used...

// adding

CPtrArray *pPoints = new CPtrArray;
aPointArrays.Add( pPoints );

// Delete any CPoints stored for undrawing

int iTot = aPointArrays.GetSize();
int iCur;
for( iCur = 0; iCur < iTot; iCur++ )
{
CPtrArray *pPoints = (CPtrArray*)aPointArrays.GetAt( iCur );
int iTot2 = pPoints->GetSize();
---
---
}

Thanks

prasad_som8-Feb-07 0:24

prasad_som

8-Feb-07 0:24

sheetal_06 wrote:
class CSpanLoad : public CCASObject
{
public:
void operator=( const CCASObject& );

private:
CPtrArray aPointArrays;
};

//spanload.cpp
void CSpanLoad::operator=( const CCASObject &src )
{

//....
}

Here you have mistaken with assignment operator.
It should be like this,

class CSpanLoad : public CCASObject 
{
public:
void operator=( const CCASObjectCSpanLoad& );

private:
CPtrArray aPointArrays;
};

//spanload.cpp
void CSpanLoad::operator=( const CCASObjectCSpanLoad& src )
{

//....
}

Prasad
Notifier using ATL | Operator new[],delete[][^]