C / C++ / MFC

David Crow10-Oct-07 2:57

10-Oct-07 2:57

jay_p_patel wrote:
InternetFindNextFile function falis

So what does GetLastError() return?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

onlyjaypatel10-Oct-07 19:11

onlyjaypatel

10-Oct-07 19:11

i wrote in that code
ERROR_INTERNET_INVALID_OPERATION(12016)

David Crow11-Oct-07 2:52

11-Oct-07 2:52

Your code snippet is next to impossible to read. I can't tell what you've got commented out and what's actual code. Please reformat it AND make use of the <pre> tags.

You need something similar to:

HINTERNET hOpen = InternetOpen(...);
if (hOpen != NULL)
{
    HINTERNET hConnect = InternetConnect(hOpen, ...);
    if (hConnect != NULL)
    {
        WIN32_FIND_DATA findData;
        
        HINTERNET hFind = FtpFindFirstFile(hConnect, NULL, &findData, ...);
        if (hFind != NULL)
        {
            do
            {
                ...
            } while (InternetFindNextFile(hFind, &findData))
        }
    }
}

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Where is the first data location in Monochrome BMP image?

onlyjaypatel16-Oct-07 20:53

onlyjaypatel

16-Oct-07 20:53

Hello Sir,

The code you send me that i already tried.
when i use
HINTERNET hFind = FtpFindFirstFile(hConnect, NULL, &findData, ...);
it returns hFind = NULL
and in GetLastError it returns
Error No.12018 ERROR_INTERNET_INCORRECT_HANDLE_TYPE

i read in msdn that we can use InternetOpenUrl in place of FtpFindFirstFile
HINTERNET hFind = InternetOpenUrlhInternetOpen,sUrl,NULL,0,INTERNET_FLAG_RAW_DATA| INTERNET_FLAG_RELOAD|
INTERNET_FLAG_DONT_CACHE,0);

now hFind is not Null but when i use this hFind in
InternetFindNextFile API than it return false.
So this is the problem.

Anyway thanx for helping me.
sorry for ur inconvinience.
Smile | :)

Mohammad Khodaea9-Oct-07 19:24

Mohammad Khodaea

9-Oct-07 19:24

Hi dear
I want to ask you if you know where the first address for image data in monochrome bitmap is. I know the header allocate 54 bytes but I am not sure about this in Monochrome images.
Please if you can tell me where is the location of the first data, I will be so thankful.
Note: Monochrome Bitmaps (one bit per pixel)
Thanks Confused | :confused:

Re: Where is the first data location in Monochrome BMP image?

Nishad S9-Oct-07 19:48

Nishad S

9-Oct-07 19:48

The image data address is stored in the image header itself. So better you read it and check. I think you are not considering color table info.

- NS -

Re: Where is the first data location in Monochrome BMP image?

Mark Salsbery10-Oct-07 6:19

Mark Salsbery

10-Oct-07 6:19

I answered this before for you and you still haven't provided enough information.

If the BMP is a file, the file begins with a BITMAPFILEHEADER structure.
The bfOffBits member of this struct is the offset of the pixel bits from the
beginning of the file.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Read stream of bytes in a buffer as a String [modified]

CodingLover9-Oct-07 18:40

9-Oct-07 18:40

Hi all, here's my question.

First I read a binary file, which includes large number of streams of bytes. Each stream has specific details. Using a buffer I read each stream and extract some details. Actually stream consist two parts, fixed data and a message. Fixed data length actually fixed in 24 number of bytes. Rest of the bytes include the message. What I want to do is, read the bytes which message include and print as a String(actually as a message).

Those bytes are in the buffer and I know how many bytes are there.

I work on Visual Studio .Net 2003

Can you guys help me to solve this.

Thanks Smile | :)

-- modified at 0:45 Wednesday 10th October, 2007 -- adding more details

Hi all....

Re: Read stream of bytes in a buffer as a String [modified]

chandu0049-Oct-07 18:57

chandu004

9-Oct-07 18:57

Eranga Thennakoon wrote:
What I want to do is, read the bytes which message include and print as a String(actually as a message).

this sentence is not clear can you just elaborate it?

CodingLover9-Oct-07 19:05

9-Oct-07 19:05

Ok, after reading each stream I've found that number of bytes which include the message of each and every stream separately. As a example,

stream 1 - message use 4 bytes
stream 2 - message use 1500 bytes
stream 3 - message use 100 bytes
etc..

Right now all those bytes are in a buffer. What I want to do is read that bytes in the buffer and find the message there, I mean read stream 1 bytes of 4 and find the message. Then read the stream 2 bytes of 1500 and find the message and so on

I think it is clear now. Smile | :)

-- modified at 1:10 Wednesday 10th October, 2007

I appreciate your help all the time...

chandu0049-Oct-07 19:17

chandu004

9-Oct-07 19:17

if you are able to read the number of bytes in the message from the stream,
i dont understand whats the problem in reading the message, since you know the size of the message.
on thing please be specific.
all the data, what you call it as a stream is available in the file?
and what is that you are referring the buffer as?

CodingLover9-Oct-07 19:28

9-Oct-07 19:28

No, only thing is that I know the number of bytes use a message. I'm confusing how to read it, and get the message. If you want I can put my code here. Smile | :)

I appreciate your help all the time...

ktm TechMan9-Oct-07 20:56

ktm TechMan

9-Oct-07 20:56

Maintain a counter where you are.
In a loop read till the end of the file.
Inside the loop,
read the length, using memcpy in a DWORD and update counter
use ur string class, and copy the buffer, till that length just read like string
s=string(buffer+counter,length); (assuming there is a constructor like this,which many
have)
update counter
end loop

Simple, Cool | :cool:

CodingLover9-Oct-07 21:05

9-Oct-07 21:05

I'm not clear what's usage of a counter. If I read the message just after finding the length I think it is easy, because to find the length of each and every stream message I have to use a loop. Difficulty I come across with is some message length is higher than the buffer size I used.

What's your comment? Smile | :)

I appreciate your help all the time...

chandu00410-Oct-07 0:22

chandu004

10-Oct-07 0:22

if you have posted your code to my mail id,
then i will get back to you in a couple of hours. keep in touch.

David Crow10-Oct-07 2:56

10-Oct-07 2:56

Eranga Thennakoon wrote:
Can you guys help me to solve this.

Sure, which part are you stuck on? What code do you have so far?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

CodingLover10-Oct-07 19:16

10-Oct-07 19:16

Ok, here is my code. Sorry I don't use tags here, it gives a real mess to read the code correctly.

=============================================================================================================
#include <iostream>
#include <fstream>
#include <string>

using namespace std ;

ofstream filedata ;

// Packet content of initial 16 bytes
struct pac_cont
{
unsigned int des_list ;
unsigned int mem_ID ;
unsigned char dm_con ;
unsigned char ser_ID ;
unsigned short act ;
};

void dataExtract(int length, char *buffer)
{
struct pac_cont* p = (struct pac_cont*)buffer;

filedata.open( "RecordData.txt", ios::app ) ;

if(filedata.is_open())
{
filedata << "\t" << static_cast<int>(p->des_list) << "\t\t" << static_cast<int>(p->mem_ID)
<< "\t\t" << static_cast<int>(p->dm_con) << "\t\t" << static_cast<int>(p->ser_ID)
<< "\t\t" << static_cast<int>(p->act) << "\n";
filedata.close() ;
}

else
{
filedata << "Error in opening file RecordData.txt\n" ;
}
}

int main ()
{
ifstream fileopen ;
ofstream filerecord ;
char buffer[5000] ;
unsigned int tmp_len = 0 ; // Length of a stream
int count_mess = 0 ; // Count total message
int ID = 1 ; // Stream ID

// Open the file in binary format
fileopen.open ( "G00046_002_01.srf", ios_base::binary ) ;

// Record the stream length
filerecord.open ( "RecordLength.txt", ios_base::out ) ;

if((fileopen.is_open()) && (filerecord.is_open()))
{
// Headers of the RecordLength.txt file
filerecord << "Stream ID\tLength\t\tDescription\n\n" ;

// Headers of the RecordData.txt file
filedata.open ( "RecordData.txt", ios_base::out ) ;
if(filedata.is_open())
{
filedata << "Destination List\t" << "Member ID\t" << "Data/Message\t"
<< "Service ID\t" << "Activity ID\n\n" ;
filedata.close() ;
}

else
{
cout << "Error in opening file\n" ;
}

while(!fileopen.eof())
{
fileopen.read(buffer, 4); // Dummy read of 4 bytes
fileopen.read(buffer, 4) ; // Read next 4 bytes

tmp_len = *(unsigned int*)buffer ; // Integer value of previous 4 bytes

if(tmp_len <= 5000)
{
filerecord << ID << "\t\t" << tmp_len << "\t\t" << "-\n" ;

if(tmp_len > 16)
{
// Procesing initial 16 bytes
fileopen.read(buffer, 16) ;
dataExtract(16, buffer) ;

// Move the buffer pointer
fileopen.seekg((tmp_len - 16), ios_base::cur) ;
}

else
{
cout << "Stream is in wrong length\n" ;
}

}

else
{
filerecord << ID << "\t\t" << tmp_len << "\t\t" << "Large Size - More than 5000 bytes\n" ;

// Processing intial 16 bytes
fileopen.read(buffer, 16) ;
dataExtract(16, buffer) ;

// Move the buffer pointer
fileopen.seekg((tmp_len - 16), ios_base::cur) ;
}

ID++ ;
count_mess++ ;
}

cout << "Number of streams: " << ( ID - 1 ) << endl ;
cout << "Number of messages: " << ( count_mess - 1 ) << endl ;
fileopen.close() ;
filerecord.close() ;
}

else
{
cout << "Error in opening files" << endl ;
}

cin.get() ;
return 0 ;
}

============================================================================================================

I'll comment it as much as possible. First I read a binary file, and found how many stream of bytes are there. Actually length of those streams are not same.

Basically each stream contain three part, four bytes for part one, four bytes for part two and int value of that four bytes gives the next part bytes. The third part have 16 fixed bytes at the beginning of each. I've extract the data there using dataExtract() function, you can see that. Up to now it is ok.

Now I want to read the bytes in part three except first 16 bytes. There is a message, actually record from a online chat. I want to read it and write to a file. How can I do that.

Thanks. Smile | :)

I appreciate your help all the time...

David Crow11-Oct-07 3:04

11-Oct-07 3:04

What does stepping through each line of code with the debugger reveal?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

CodingLover11-Oct-07 17:48

11-Oct-07 17:48

DavidCrow wrote:
debugger reveal

Please can you explain it little more. It is really new for me.

Eranga Smile | :)

I appreciate your help all the time...

David Crow12-Oct-07 3:24