Reading a registry value into an LPSTR

http://www.mentalis.org/vbtutor/api1p.htm  go down to API parameter types.

An LPSTR as you know is just a pointer to a regular null-terminated string.

no, perhaps i didn't make myself clear. I can return an LPSTR to VB, but I'm having problems reading the value from the registry into a LPSTR variable. It's that I need help with

@TheBaker:

> no, perhaps i didn't make myself clear. I can return an LPSTR to VB, but I'm
> having problems reading the value from the registry into a LPSTR variable.
> It's that I need help with

If you query a string using RegQueryValue or RegQueryValueEx, then the value will be ANSI or UNICODE depending on whether or not you call the ANSI version (RegQueryValueExA) or the UNICODE version (RegQueryValueExW).  Since you want a LPSTR, then you need to call the ANSI version to get an ANSI string (RegQueryValueExA), or you can call the UNICODE version, and then convert to an ANSI string.

Hope That Helps,
Dex*

cheers. Any chance of some code?

Cheers Dexstar (Dex*)

I know I've already awarded the points, but if anyone could help me sort it out, there'll be more points in it! My code is shown below. I've tried todo what Dex* said, but it doesn't work (or I'm doing something wrong!

LPSTR __stdcall GetCustomFormat(int iCustom){
      LPSTR lpReturn = "Coming Soon...";
      HKEY hKey;
      DWORD dwDisposition;
      DWORD DataType;
    DWORD DataCount=65;

      RegCreateKeyEx(HKEY_CURRENT_USER, "Software\\MyApp", 0, NULL, 0, KEY_ALL_ACCESS, NULL, &hKey, &dwDisposition);

      RegQueryValueExA(hKey, "Custom1", 0, &DataType,(unsigned char*)lpReturn, &DataCount);
      
      RegCloseKey(hKey);

      return lpReturn;
}

The main issue for this is memory... Who allocates and who frees it?  The problem is that you don't know how much memory is even needed.  The key there is to call RegQueryValueExA with a NULL param for the data.  In that case, it will just fill in the size for you, and then you can allocate the memory.  Like this:
      RegQueryValueExA(hKey, "Custom1", 0, &DataType, NULL, &DataCount);

Then you can allocate the memory:
      DataCount++; // Add one for NULL
      LPSTR lpReturn = new char[DataCount];
      RegQueryValueExA(hKey, "Custom1", 0, &DataType,(unsigned char*)lpReturn, &DataCount);

Then you can return lpReturn, but the caller is responsible for freeing the memory.

You should also check the return values for those API calls, and handle errors.  Your problem could be one of those APIs are failing.

Dex*

Cheers that works, but if the value = "" I get the following: Íýýýý
Any ideas how to check whether lpReturn = Íýýýý then change lpReturn to "".

I've tried:

if(lpReturn == "Íýýýý"){
      lpReturn = "";
}

but it didn't work. I also tried:

if(lpReturn == NULL){
      lpReturn = "";
}

but again, it didn't work.

Okay, if the value is empty, then after the first call to RegQueryValueExA, then DataCount will be 0.  So check for that.

     if ( DataCount > 0 )
     {
          DataCount++; // Add one for NULL
          LPSTR lpReturn = new char[DataCount];
          RegQueryValueExA(hKey, "Custom1", 0, &DataType,(unsigned char*)lpReturn, &DataCount);
          return lpReturn
     }
     else
     {
          // The value is empty
          return NULL;
     }

Cheers Dexstar. I'll give you 50 extra points for that help, but you'll need to tell me how I can give them to you since this post is closed.

Sorry, I have been out of the office sick for the past few days...  :|

There are 2 ways to do it.  One way it to post a "Points For Dexstar" question, and then post a link to this question in there.  Then I'll post something and you accept my answer...  The other way is to post a question in the Community Support forum, and ask them to re-open this question.  Then you can change the points value, and re-accept an answer.

Info on "Points For" questions:  https://www.experts-exchange.com/help.jsp#hi76
Info on re-opening this question: https://www.experts-exchange.com/help.jsp#hi75

I think the first way is easier because you don't need to involve the Moderators, but whatever you feel comfortable with.

Dexstar, get your extra point here: https://www.experts-exchange.com/questions/20808856/For-Dexstar-re-Reading-a-registry-value-into-an-LPSTR.html