Problem with string to function argument

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Problem with string to function argument

 
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  #1
Aug 15th, 2008
Hi all,

I am trying to optimize one of my applications by cutting down on the number of function calls I am making. I have decided to do this by reading definitions out of a file and using them as the argument for the function.

C++ Syntax (Toggle Plain Text) 
  1. char registryHive[MAX_PATH];
  2.                         ZeroMemory ( registryHive, MAX_PATH );
  3.  
  4.                         FILE * ep = fopen( "test.txt", "r" );
  5.  
  6.                         while ( !feof(ep) ) 
  7.                         {
  8.                               fgets(registryHive, MAX_PATH, ep);  
  9.  
  10.                               HKEY regHandle; 
  11.  
  12.                               char* pHive = registryHive;
  13.                               char* pKey = registryHive; 
  14.  
  15.                               while( *pKey != '\\' ) 
  16.                               {
  17.                                      pKey++; 
  18.                                      if ( *pKey == '\0' )
  19.                                      break; 
  20.                               }
  21.                               *(pKey++) = '\0';
  22.  
  23.                               if ( strcmp(pHive, "HKEY_LOCAL_MACHINE") == 0  ) 
  24.                                  regHandle = HKEY_LOCAL_MACHINE;
  25.                               else if ( strcmp(pHive, "HKEY_CURRENT_USER") == 0 ) 
  26.                                  regHandle = HKEY_CURRENT_USER; 
  27.  
  28.                               RemoveRegKeys(regHandle, pKey, false); 
  29.                         }
  30.  
  31.                         fclose(ep);

For example, if I wanted to remove HKEY_LOCAL_MACHINE\Test, I would put that in my file and the code should get HKEY_LOCAL_MACHINE for pHive and Test for pKey.

Here is the definition of RemoveRegKeys:

C++ Syntax (Toggle Plain Text) 
  1. int RemoveRegKeys(HKEY regAddressOne, char *regAddressTwo, bool silent)
  2. {
  3.     int doesExist; 
  4.     char buffer[255];
  5.     char output[255];
  6.  
  7.     ZeroMemory(buffer, 255);
  8.     ZeroMemory(output, 255); 
  9.  
  10.     char logname[100];
  11.  
  12.     GetEnvironmentVariable("HOMEDRIVE", logname, 100);
  13.     strcat(logname, "\\JavaRa.log");
  14.  
  15.     // FILE *fp;
  16.     // fp = fopen(logname, "a");
  17.  
  18.     HKEY hkey;
  19.     int check = RegOpenKeyEx(regAddressOne, regAddressTwo, 0, KEY_SET_VALUE, &hkey);
  20.     doesExist = SHDeleteKey(regAddressOne, regAddressTwo);
  21.     RegCloseKey(hkey);
  22.  
  23.     char test[80];
  24.     sprintf(test, "key: %s\ncheck: %i\ndoesExist: %i", regAddressTwo, check, doesExist); 
  25.     MessageBox(0, test, 0, 0); 
  26.  
  27.     if (doesExist == 0)
  28.     {
  29.        TCHAR szOne[MAX_PATH];
  30.        ZeroMemory(szOne, MAX_PATH); 
  31.  
  32.        switch(globalLanguageChosen)
  33.        {
  34.             // ...
  35.        }
  36.  
  37.        // fprintf(fp, "Found and removed: %s\r\n", regAddressTwo);
  38.        sprintf(buffer, "%s %s\r\n", szOne, regAddressTwo);
  39.        lstrcpy(output, buffer);
  40.  
  41.        if (silent != true)
  42.        {
  43.            MessageBox(0, output, "Output", MB_OK | MB_ICONINFORMATION); 
  44.        }
  45.  
  46.     }
  47.     // fclose(fp); 
  48. }

My problem is, RegOpenKeyEx and SHDeleteKey always return 2 when I call them through RemoveRegKeys in the way that I have in the first code snippet. If I manually define a string, the function works fine. Is this a problem with the way I am reading the string out of the file, or am I corrupting the string somehow?

Thanks for your help.

If you need me to explain further, let me know.

Regards,
Paul
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Re: Problem with string to function argument

 
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  #2
Aug 15th, 2008
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Originally Posted by Prm753
I am trying to optimize one of my applications by cutting down on the number of function calls I am making. I have decided to do this by reading definitions out of a file and using them as the argument for the function.
You've probably already considered this, but file operations are notorious for being very slow. Going by what you've shown, I don't think replacing a few function calls with an I/O bound performance drain will be an improvement.
If at first you don't succeed, keep on sucking until you do succeed.
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Re: Problem with string to function argument

 
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  #3
Aug 15th, 2008
C++ Syntax (Toggle Plain Text) 
  1.                         while ( !feof(ep) ) 
  2.                         {
  3.                               fgets(registryHive, MAX_PATH, ep);
Note that this is not a good idea.

My suggestion:
C++ Syntax (Toggle Plain Text) 
  1.                         while ( fgets(registryHive, MAX_PATH, ep) ) {
Yes, it does the same thing.
dwk

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Re: Problem with string to function argument

 
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  #4
Aug 15th, 2008
The last char in the registryHive buffer after fgets() call is '\n' if it was a well-formed text file.
Of course, it's not a part of registry key...
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