How to create a DWORD using C++?

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September 11th, 2006, 05:24 AM

Cyberfreak

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How to create a DWORD using C++?

I've tried many different ways to write a program that ones opened, it will create a DWORD file in a registry folder and set the DWORD's value to 1- but I seem to be missing something because the complier won't let me compile it.

Can someone please write an example of a program like that so that I can see what I missed in some of the programs that I tried to write.
Thanks.

September 11th, 2006, 05:42 AM

costas

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Sorry, I can't help; I have no idea.

Costas

September 11th, 2006, 06:04 AM

Itsacon

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afaik, the best way is still to create a .reg file, and call regedit with that file using the system() call from C.

Search google to see how modifying the registry by means of .reg files works.

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September 11th, 2006, 08:50 AM

Cyberfreak

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Quote:

Originally Posted by Itsacon

afaik, the best way is still to create a .reg file, and call regedit with that file using the system() call from C.

Search google to see how modifying the registry by means of .reg files works.

Why didn't I think of that. Thats a great idea, thanks.

September 11th, 2006, 09:26 AM

Itsacon

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You're welcome. Good luck :-)

September 11th, 2006, 05:53 PM

ubergeek

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C Code:

Original - C Code
#include <windows.h> int main() { HKEY hHKCU = NULL, hMyKey = NULL; DWORD value = 1; if (RegOpenKeyEx(HKEY_CURRENT_USER, NULL, 0, KEY_WRITE, &hHKCU) == ERROR_SUCCESS) { if (RegCreateKeyEx(hHKCU, "My_Subkey\\MyKey", 0, NULL, 0, KEY_WRITE, NULL, &hMyKey, NULL) == ERROR_SUCCESS) { RegSetValueEx(hMyKey, "ThisIsADword", 0, REG_DWORD, (BYTE*)&value, sizeof(DWORD)); RegCloseKey(hMyKey); } } return 0; }

 
#include <windows.h>
 
int main()
{
    HKEY hHKCU = NULL, hMyKey = NULL;
    DWORD value = 1;
    if (RegOpenKeyEx(HKEY_CURRENT_USER, NULL, 0, KEY_WRITE, &hHKCU) == ERROR_SUCCESS)
    {
        if (RegCreateKeyEx(hHKCU, "My_Subkey\\MyKey", 0, NULL, 0, KEY_WRITE, NULL, &hMyKey, NULL) == ERROR_SUCCESS)
        {
            RegSetValueEx(hMyKey, "ThisIsADword", 0, REG_DWORD, (BYTE*)&value, sizeof(DWORD));
            RegCloseKey(hMyKey);
        }
 
    }
 
    return 0;
}

Creates a key under HKCU\My_Subkey\MyKey\ThisIsADword with type REG_DWORD and value 1. I'm on WinXP SP2 using Dev-C++.

September 12th, 2006, 07:05 AM

Cyberfreak

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Quote:

Originally Posted by ubergeek

C Code:

Original - C Code
#include <windows.h> int main() { HKEY hHKCU = NULL, hMyKey = NULL; DWORD value = 1; if (RegOpenKeyEx(HKEY_CURRENT_USER, NULL, 0, KEY_WRITE, &hHKCU) == ERROR_SUCCESS) { if (RegCreateKeyEx(hHKCU, "My_Subkey\\MyKey", 0, NULL, 0, KEY_WRITE, NULL, &hMyKey, NULL) == ERROR_SUCCESS) { RegSetValueEx(hMyKey, "ThisIsADword", 0, REG_DWORD, (BYTE*)&value, sizeof(DWORD)); RegCloseKey(hMyKey); } } return 0; }

 
#include <windows.h>
 
int main()
{
    HKEY hHKCU = NULL, hMyKey = NULL;
    DWORD value = 1;
    if (RegOpenKeyEx(HKEY_CURRENT_USER, NULL, 0, KEY_WRITE, &hHKCU) == ERROR_SUCCESS)
    {
        if (RegCreateKeyEx(hHKCU, "My_Subkey\\MyKey", 0, NULL, 0, KEY_WRITE, NULL, &hMyKey, NULL) == ERROR_SUCCESS)
        {
            RegSetValueEx(hMyKey, "ThisIsADword", 0, REG_DWORD, (BYTE*)&value, sizeof(DWORD));
            RegCloseKey(hMyKey);
        }
 
    }
 
    return 0;
}

Creates a key under HKCU\My_Subkey\MyKey\ThisIsADword with type REG_DWORD and value 1. I'm on WinXP SP2 using Dev-C++.

Thanks.

September 14th, 2006, 07:34 AM

Cyberfreak

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One more question.
If I wanted to write a program that creates a REG_SZ file, so I would write REG_SZ = This is a reg file (for example) instead of DWORD value = 1 and change REG_DWORD to REG_SZ and the sizeof(DWORD) to sizeof(REG_SZ)?
Thanks.

September 14th, 2006, 05:17 PM

ubergeek

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I haven't tried it, but to change to REG_SZ I would first try these steps:
-change DWORD value = 1; to probably LPCSTR value = "This is a registry key.";
-change REG_DWORD to REG_SZ in the RegSetValueEx function call
-the last parameter to RegSetValueEx is the length of the data, so change it to the actual length of the string, i.e. strlen(value) (or count the chars in value beforehand and add 1 for the null terminator)
-change the (BYTE*)&value to just (BYTE*)value since an LPCSTR is already a pointer (to some form of char)

How to create a DWORD using C++?

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