Filter Library

Camera

Interface Physics

GetInstallPath.cpp

/*
 * GetInstallPath.cpp -
 *
 * Compile: cl -GX -Ox -MT GetInstallPath.cpp
 */

// #include <afx.h>
// #include <windows.h>
// 
// #include <stdio.h>              // for FILENAME_MAX
// #include <iostream>

#include "stdafx.h"                     // for common (pre-compiled) headers
//#include <cfl/stdafx.h>                 // for common (pre-compiled) headers

/**
 * obtain the Camera installation directory from the registry.
 */
CString GetInstallPath()
{
   const char* LPMCamera   = "Software\\LPMCamera";
   const char* InstallPath = "InstallPath";

   static unsigned char *path = NULL;

   /*
    * return cached value, if available:
    */
   if ( 0 != path )
   {
      return path;
   }

   /*
    * open the registry key HKCU\Software\LPMCamera:
    */
   HKEY regKey;

   if ( 0 != RegOpenKey(
      HKEY_CURRENT_USER,        // handle to open key
      LPMCamera,                // address of name of subkey to open
      &regKey                   // address of handle to open key
   ) )
   {
      return "[error opening registry key]";
   }

   /*
    * query the length of registry value InstallPath:
    */
   DWORD valType;
   DWORD valLength;

   if ( 0 != RegQueryValueEx(
     regKey,                    // handle to key to query
     InstallPath,               // address of name of subkey to open
     NULL,                      // reserved
     &valType,                  // address of buffer for value type
     NULL,                      // address of data buffer
     &valLength                 // address of data buffer size
   ) )
   {
      return "[error reading registry value]";
   }

   /*
    * allocate space; valLength includes trailing '\0':
    */
   if ( 0 == ( path = new unsigned char[ valLength ] ) )
   {
      return "[memory allocation error]";
   }

   /*
    * query the contents of registry value InstallPath:
    */
   if ( 0 != RegQueryValueEx(
     regKey,                    // handle to key to query
     InstallPath,               // address of name of subkey to open
     NULL,                      // reserved
     &valType,                  // address of buffer for value type
     (unsigned char*)path,      // address of data buffer
     &valLength                 // address of data buffer size
   ) )
   {
      return "[error reading registry value]";
   }

   /*
    * close the registry key:
    */
   if ( 0 != RegCloseKey(
     regKey                     // handle to key to close
   ) )
   {
      return "[error closing registry key]";
   }

   return path;
}

/*
 * end of file
 */

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