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UpdateResource

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7 Sep 20032 min read 175.2K   60   42
How to manipulate raw resources (RT_RCDATA) using UpdateResource().

Introduction

Over the years, I've seen various flavors of the question "How do I include a file or data with my program that I can extract at run-time and do something with it?" For example, the asker might have had a .WAV file or a .MDB (MS Access) file that s/he wanted to include in the actual executable itself. For one reason or another, they do not want to package the two files separately. One advantage this has over a separate data/configuration file is that it'll never get lost. If the user decides they want to start fresh, they can remove everything but the application itself, and when the application is started up again, it extracts an empty database, all without the user knowing the behind-the-scenes details.

So thre are really two questions on the table here: "How to include the file?" and "Once the file is included, how to extract it and 'use' it?" Let's look at a simple example.

Including the file

In this example, I'll show the necessary code to take the entire Windows calculator (calc.exe) and add it as a resource to some test .EXE. The .EXE could just as easily be the application where these code snippets reside. The first thing we must do is open calc.exe in read-only mode, and read the entire file into a buffer.

HANDLE hFile;
DWORD dwFileSize,      
      dwBytesRead;
LPBYTE lpBuffer;

hFile = CreateFile(L"C:\\Winnt\\System32\\calc.exe", GENERIC_READ, 
                   0,
                   NULL,
                   OPEN_EXISTING,
                   FILE_ATTRIBUTE_NORMAL,
                   NULL);

if (INVALID_HANDLE_VALUE != hFile)
{
    dwFileSize = GetFileSize(hFile, NULL);

    lpBuffer = new BYTE[dwFileSize];

    if (ReadFile(hFile, lpBuffer, dwFileSize, &dwBytesRead, NULL) != FALSE)
    {
        // do something with lpBuffer here
    }

    delete [] lpBuffer;        
    
    CloseHandle(hFile);
}

Updating the resource data

Now it's simply a matter of getting access to the resource data of the test file and updating it with the data pointed to by lpBuffer. The third parameter to UpdateResource() is the name we want to give the resource. I just chose an arbitrary name of 104.

HANDLE hResource;

hResource = BeginUpdateResource(L"C:\\...\\t3.exe", FALSE);
if (NULL != hResource)
{
    if (UpdateResource(hResource, 
        RT_RCDATA, 
        MAKEINTRESOURCE(104), 
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), 
        (LPVOID) lpBuffer, 
        dwFileSize) != FALSE)
    {
        EndUpdateResource(hResource, FALSE);
    }
}

At this point, you can actually open the test file with Visual Studio and see the addition of our data in the "Data" section. Be sure to open the file as a "resource"!

Extracting the data

So now your application has been delivered, and you need to extract the resource data.

Extracting the resource data uses functions from the same family as UpdateResource(). The required steps are to load the file containing the resource data, find the desired resource, load the resource, and then lock it.

HMODULE hLibrary;
HRSRC hResource;
HGLOBAL hResourceLoaded;
LPBYTE lpBuffer;

hLibrary = LoadLibrary(L"C:\\...\\t3.exe");
if (NULL != hLibrary)
{
    hResource = FindResource(hLibrary, MAKEINTRESOURCE(104), RT_RCDATA);
    if (NULL != hResource)
    {
        hResourceLoaded = LoadResource(hLibrary, hResource);
        if (NULL != hResourceLoaded)        
        {
            lpBuffer = (LPBYTE) LockResource(hResourceLoaded);            
            if (NULL != lpBuffer)            
            {                
                // do something with lpBuffer here            
            }
        }    
    }

    FreeLibrary(hLibrary);
}

Saving the data to a file

All that's left is to create a file with the data pointed to by lpBuffer. Nothing special needs to be done to the data. It's the entire Windows calculator!

DWORD dwFileSize,
      dwBytesWritten;
HANDLE hFile;

dwFileSize = SizeofResource(hLibrary, hResource);

hFile = CreateFile(L"C:\\Winnt\\Temp\\calc2.exe",
                   GENERIC_WRITE,
                   0,
                   NULL,
                   CREATE_ALWAYS,
                   FILE_ATTRIBUTE_NORMAL,
                   NULL);

if (INVALID_HANDLE_VALUE != hFile)
{
    WriteFile(hFile, lpBuffer, dwFileSize, &dwBytesWritten, NULL);

    CloseHandle(hFile);
}

Now you should be able to run the newly created file, calc2.exe! As I indicated at the beginning of the article, this can be done with any sort of file that you want to include along with your main application or DLL.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


Written By
Software Developer (Senior) Pinnacle Business Systems
United States United States

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Comments and Discussions

 
GeneralCursor Resource Pin
nenfa23-Jul-10 3:57
nenfa23-Jul-10 3:57 
AnswerRe: Cursor Resource Pin
David Crow23-Jul-10 4:51
David Crow23-Jul-10 4:51 
GeneralRe: Cursor Resource Pin
nenfa26-Jul-10 22:52
nenfa26-Jul-10 22:52 
QuestionRe: Cursor Resource Pin
David Crow27-Jul-10 2:56
David Crow27-Jul-10 2:56 
GeneralBITMAP Pin
filipe_madureira29-May-09 5:27
filipe_madureira29-May-09 5:27 
GeneralRe: BITMAP Pin
David Crow29-May-09 10:49
David Crow29-May-09 10:49 
GeneralRe: BITMAP Pin
filipe_madureira1-Jun-09 22:31
filipe_madureira1-Jun-09 22:31 
QuestionIs it possible to execute the data? Pin
flaushi20-Mar-09 2:30
flaushi20-Mar-09 2:30 
AnswerRe: Is it possible to execute the data? Pin
David Crow20-Mar-09 2:47
David Crow20-Mar-09 2:47 
GeneralRe: Is it possible to execute the data? Pin
marc ochsenmeier6-Jul-10 2:01
marc ochsenmeier6-Jul-10 2:01 
QuestionRe: Is it possible to execute the data? Pin
David Crow6-Jul-10 3:29
David Crow6-Jul-10 3:29 
AnswerRe: Is it possible to execute the data? Pin
marc ochsenmeier6-Jul-10 3:39
marc ochsenmeier6-Jul-10 3:39 
GeneralThe article helped a lot Pin
adenissov18-Nov-08 12:30
adenissov18-Nov-08 12:30 
AnswerA way for updating application ICON (from .ICO file) Pin
Elad raz15-Oct-08 6:35
Elad raz15-Oct-08 6:35 
QuestionRe: A way for updating application ICON (from .ICO file) Pin
David Crow15-Oct-08 6:42
David Crow15-Oct-08 6:42 
AnswerRe: A way for updating application ICON (from .ICO file) Pin
Elad raz15-Oct-08 6:48
Elad raz15-Oct-08 6:48 
GeneralRe: A way for updating application ICON (from .ICO file) Pin
David Crow15-Oct-08 6:55
David Crow15-Oct-08 6:55 
GeneralBe sure to apply your checks.. Pin
ChizI2-May-08 5:47
ChizI2-May-08 5:47 
GeneralRe: Be sure to apply your checks.. Pin
David Crow2-May-08 5:53
David Crow2-May-08 5:53 
QuestionIcon resources Pin
ArnorBld11-Dec-06 20:13
ArnorBld11-Dec-06 20:13 
AnswerRe: Icon resources Pin
David Crow13-Dec-06 4:19
David Crow13-Dec-06 4:19 
GeneralRe: Icon resources Pin
ArnorBld14-Dec-06 7:05
ArnorBld14-Dec-06 7:05 
GeneralJust cant get any better Pin
Rajesh R Subramanian28-Jun-06 1:14
professionalRajesh R Subramanian28-Jun-06 1:14 
GeneralRe: Just cant get any better Pin
David Crow28-Jun-06 2:28
David Crow28-Jun-06 2:28 
GeneralUpdateResource RT_ICON Pin
CG2i0331-May-06 3:13
CG2i0331-May-06 3:13 

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