C / C++ / MFC

Re: create message queues

2-Mar-10 1:31

Do you think is there or are you sure that it is there?
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Eugen Podsypalnikov2-Mar-10 0:39

Eugen Podsypalnikov

2-Mar-10 0:39

Please point to the line #23 Smile | :)

You could use your structure by instance (without malloc/free):

msgbuf mb = {0};
mb.mtype  = 1;
...
msgsnd(.., &mb,..);
...

Check your definition of Irrationality[^] Smile | :)

1 - Avicenna
5 - Hubbard
3 - Own definition

Re: create message queues

0xeffe6-May-10 9:14

0xeffe

6-May-10 9:14

I have got the solution for your problem.

when you type cat /usr/include/sys/msg.h you can see that the struct is commented out when __USE_GNU is not defined.

/usr/include/sys/msg.h:

#ifdef __USE_GNU
/* Template for struct to be used as argument for `msgsnd' and `msgrcv'.  */
struct msgbuf
  {
    long int mtype;             /* type of received/sent message */
    char mtext[1];              /* text of the message */
  };
#endif

A bit of Googeling brings the result that you should #define _GNU_SOURCE to use that struct.
It is important to define it before you #include <sys/msg.h>.

I hope i helped.
greetings 0xeffe

TLDR solution:

#define _GNU_SOURCE
#include <sys/msg.h>

Hide Command Prompt in Console Application

avika1-Mar-10 23:42

1-Mar-10 23:42

I want to hide the command prompt while running my console application.

I have used following code -

HWND hWnd = GetConsoleWindow();
if(hWnd)
{
ShowWindow(hWnd, SW_HIDE);
}

This code is working fine, but for a moment it shows the command prompt and then hide it.

Is there any way to hide Command Prompt completely?

Rajesh R Subramanian1-Mar-10 23:55

Rajesh R Subramanian

1-Mar-10 23:55

1. Why do you need to do this?
2. If you don't want a window, you could use a Win32 application instead of a console application, where you could hide the window before it's shown.
3. Alternatively, if you're launching this console app from another app, then you could use CreateProcess[^], passing CREATE_NO_WINDOW[^] for the dwCreationFlags parameter.

“Follow your bliss.” – Joseph Campbell

avika2-Mar-10 0:04

2-Mar-10 0:04

I am not launching my application from another application.

I have to create console application because in some cases I have to show command prompt and in some cases not to show.

Rajesh R Subramanian2-Mar-10 0:11

Rajesh R Subramanian

2-Mar-10 0:11

In which case, start your console application from a Win32 app and show or hide it as needed. You cannot 'hide' a console application from within itself before the console window is shown - or none that I know of. This is because the window creation is not done by the console program, but the system does it.

The advice given in previous reply can be used if you decide to use a Win32 program for this.

“Follow your bliss.” – Joseph Campbell

sunlin72-Mar-10 0:44

sunlin7

2-Mar-10 0:44

you can alloc a console by AllocConsole function and destroy by FreeConsole when you didn't need it.
hope this will solve your problem.

Rajesh R Subramanian2-Mar-10 1:04

Rajesh R Subramanian

2-Mar-10 1:04

lisunlin wrote:
you can alloc a console by AllocConsole function and destroy by FreeConsole when you didn't need it.

I don't see how could this solve the given problem.

“Follow your bliss.” – Joseph Campbell

sunlin72-Mar-10 17:45

sunlin7

2-Mar-10 17:45

complite your project as a windows application, there will be no console during it's executeing unless you AllocConsole when application need interactiving with user, FreeConsole when you want hide the console.
Sorry for my English, I'm not good at it.

Byte Ordering MFC Serialization [Solved]

Rolf Kristensen2-Mar-10 12:22

Rolf Kristensen

2-Mar-10 12:22

Stop compiling your application as a console application, but as a windows application (Remove "console" from the compiler and linker options)

Garth Watkins1-Mar-10 23:05

Garth Watkins

1-Mar-10 23:05

Does the serialization class CArchive automatically handle byte ordering differences on different platforms ? I have a class which i am serializing on an Big Endian platform but will be deserializing it on a little endian platform. Is there anything i need to watch out for ? The only bit of info i have managed to find on the net is this article http://www.drdobbs.com/184409538;jsessionid=T1RL5VK3F2RBFQE1GHPCKHWATMY32JVN?_requestid=488503[^] However it is a bit outdated.

[Solution]
OK for those who are interested, it seems as if CArchive does not do any byte swapping at all. The reason being is that all versions of windows run the same endianess.. http://social.msdn.microsoft.com/Forums/en/windowsmobiledev/thread/04c92ef9-e38e-415f-8958-ec9f7c196fd3[^]

The two items in the CArchive class that would have anything to do with byte swapping actually do nothing at all.
i.e. CArchive::IsByteSwapping and CArchive::bNoByteSwap

Cheers
Garth

I don't really care whether or not i really care or not.

modified on Tuesday, March 2, 2010 6:29 AM

CPallini1-Mar-10 23:12

1-Mar-10 23:12

Well, you may perform a little test.
Smile | :)

[added]
I guess the outdated article's content is still true (at least for compatibility reasons).
[/added]

Garth Watkins1-Mar-10 23:17

Garth Watkins

1-Mar-10 23:17

Well....I'm just taking the easy way out Wink | ;)

Actually i was hoping someone had already performed a little test already. And i also don't currently have access to the little endian platform.

Cheers
Garth

I don't really care whether or not i really care or not.

CPallini1-Mar-10 23:31

1-Mar-10 23:31

Garth Watkins wrote:
And i also don't currently have access to the little endian platform.

You don't need: just see, with you fovourite hex editor, if the binary file is properly 'little-endianned'... Roll eyes | :rolleyes:

Garth Watkins1-Mar-10 23:44

Garth Watkins

1-Mar-10 23:44

How is that going to help ? Lets say for instance i serialize class to a file. I then open the file in a hex editor. That's going to tell me what format (Little Endian/Big Endian) the CArchive class saves data in. It's not going to tell me whether or not it gets restored in the proper way when deserializing it on another platform that has a different byte order.

Cheers
Garth

I don't really care whether or not i really care or not.

CPallini1-Mar-10 23:51

Download file from the url.

1-Mar-10 23:51

Garth Watkins wrote:
That's going to tell me what format (Little Endian/Big Endian) the CArchive class saves data in. It's not going to tell me whether or not it gets restored in the proper way when deserializing it on another platform that has a different byte order.

It should serialize it in little-endian format. That way you may be pretty confident it will work on other platforms (as quick-test result 'pretty confident' is good, anyway, I suppose checking the endianess is a bit painful).
I would say (based on Dr.Dobb's article): if you don't make mistakes, it will work.
Smile | :)

avika1-Mar-10 22:30

1-Mar-10 22:30

We want to download a file from the url.

If we are download a text file then this code will download the file successfully, but if we are trying to download a exe or even a jpg file then this code does not work fine.

We are using following code -

DWORD dwSize = 0;
DWORD dwDownloaded = 0;
LPSTR pszOutBuffer;
BOOL bResults = FALSE;
HINTERNET hSession = NULL,
hConnect = NULL,
hRequest = NULL;

hSession = WinHttpOpen( L"WinHTTP Example/1.0",
WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,
WINHTTP_NO_PROXY_NAME,
WINHTTP_NO_PROXY_BYPASS, 0);

if (hSession)
hConnect = WinHttpConnect(hSession, L"localhost.com", INTERNET_DEFAULT_HTTP_PORT, 0);
if (hConnect)
hRequest = WinHttpOpenRequest( hConnect, L"GET",
L"/CMS/upload/1.txt",
NULL, WINHTTP_NO_REFERER,
WINHTTP_DEFAULT_ACCEPT_TYPES,
WINHTTP_FLAG_REFRESH);

if (hRequest)
bResults = WinHttpSendRequest( hRequest,
WINHTTP_NO_ADDITIONAL_HEADERS, 0,
WINHTTP_NO_REQUEST_DATA, 0, 0, 0);

if (bResults)
bResults = WinHttpReceiveResponse( hRequest, NULL);

if (bResults)
{
dwSize = 0;
if (!WinHttpQueryDataAvailable( hRequest, &dwSize))
printf("Error %u in WinHttpQueryDataAvailable.\n", GetLastError());

if (dwSize > 0)
{
pszOutBuffer = new char[dwSize+1];
}

if (!pszOutBuffer)
{
printf("Out of memory\n");
dwSize=0;
}
else
{
if (dwSize>0)
{
ZeroMemory(pszOutBuffer, dwSize+1);
if (!WinHttpReadData( hRequest, (LPVOID)pszOutBuffer, dwSize, &dwDownloaded))
printf("Error %u in WinHttpReadData.\n", GetLastError());
}
}

HANDLE hFile;
DWORD dwNumWritten;
BOOL bTest;

ofstream outfile ("D:\\1.txt",ofstream::binary);
outfile.write(pszOutBuffer,sizeof(dwSize) * 50);

Please help me what I am doing wrong.

«_Superman_»1-Mar-10 22:35

«_Superman_»

1-Mar-10 22:35

You could use the URLDownloadToFile API.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

avika1-Mar-10 23:09

1-Mar-10 23:09

I have tried the method which are suggest by u, Superman but it gives following error ---

unresolved external symbol _URLDownloadToFileW@20 referenced in function "void __cdecl funDownloadFile(void)" (?funDownloadFile@@YAXXZ)

«_Superman_»1-Mar-10 23:16

«_Superman_»

1-Mar-10 23:16

Add Urlmon.lib to Project Properties -> Configuration Properties -> Linker -> Input -> Additional Dependencies.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

avika1-Mar-10 23:25

1-Mar-10 23:25

Now it is working fine ... thanks a lot buddy..

CPallini1-Mar-10 22:52

1-Mar-10 22:52

avika wrote:
but if we are trying to download a exe or even a jpg file then this code does not work fine.

What do you mean exactly?

BTW you should use the 'code block' button to post code.

avika wrote:
outfile.write(pszOutBuffer,sizeof(dwSize) * 50);

BTW2 Why 50 in the above line?

avika1-Mar-10 23:05

1-Mar-10 23:05

if We are pass only outfile.write(pszOutBuffer,sizeof(dwSize)); then it show less data in the text file. But if We pass the outfile.write(pszOutBuffer,sizeof(dwSize) * 50); then it show complete data thats why we are passing this.

CPallini1-Mar-10 23:11