레지스트리(registry) 제어코드.

	개요
	윈도우의 레지스트리에 접근하기 위한 함수 및 코드들 . RegOpenKeyEx :  특정 registry key 열기. RegEnumKeyEx :  특정 registry key 하위 키들 열거하기. RegQueryValueEx : 열린키의 지정된 value name 의 type과 data 얻기. RegSetValueEx : 1개의 registry key 의 지정된 value name 에 type과 data 기록하기.

 

	함수 RegOpenKeyEx
	LONG WINAPI RegOpenKeyEx(   _In_     HKEY    hKey,   _In_opt_ LPCTSTR lpSubKey,   _In_     DWORD   ulOptions,   _In_     REGSAM  samDesired,   _Out_    PHKEY   phkResult ); 특정 registry key 열기. registry key 란 regedit에서 보이는 경로의미함. 인자 kKey : regedit 에서 루트에 보이는 5개중 1개를 기록하면됨. 인자 lpSubkey : hKey 하위의 경로 기록. 대소문자 구분없음. RegOpenKeyEx function Opens the specified registry key. Note that key names are not case sensitive. To perform transacted registry operations on a key, call the RegOpenKeyTransacted function. Syntax C++ Copy LONG WINAPI RegOpenKeyEx( _In_     HKEY    hKey, _In_opt_ LPCTSTR lpSubKey, _In_     DWORD   ulOptions, _In_     REGSAM  samDesired, _Out_    PHKEY   phkResult ); Parameters hKey [in] A handle to an open registry key. This handle is returned by the RegCreateKeyEx or RegOpenKeyEx function, or it can be one of the following predefined keys: HKEY_CLASSES_ROOT HKEY_CURRENT_CONFIG HKEY_CURRENT_USER HKEY_LOCAL_MACHINE HKEY_USERS lpSubKey [in, optional] The name of the registry subkey to be opened. Key names are not case sensitive. The lpSubKey parameter can be a pointer to an empty string. If lpSubKey is a pointer to an empty string and hKey is HKEY_CLASSES_ROOT, phkResult receives the same hKey handle passed into the function. Otherwise, phkResult receives a new handle to the key specified by hKey. The lpSubKey parameter can be NULL only if hKey is one of the predefined keys. If lpSubKey is NULL and hKey is HKEY_CLASSES_ROOT, phkResult receives a new handle to the key specified by hKey. Otherwise, phkResult receives the same hKey handle passed in to the function. For more information, see Registry Element Size Limits. ulOptions [in] Specifies the option to apply when opening the key. Set this parameter to zero or the following: Value Meaning REG_OPTION_OPEN_LINK The key is a symbolic link. Registry symbolic links should only be used when absolutely necessary.   samDesired [in] A mask that specifies the desired access rights to the key to be opened. The function fails if the security descriptor of the key does not permit the requested access for the calling process. For more information, see Registry Key Security and Access Rights. phkResult [out] A pointer to a variable that receives a handle to the opened key. If the key is not one of the predefined registry keys, call the RegCloseKey function after you have finished using the handle. Return value If the function succeeds, the return value is ERROR_SUCCESS. If the function fails, the return value is a nonzero error code defined in Winerror.h. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to get a generic description of the error. Remarks Unlike the RegCreateKeyEx function, the RegOpenKeyEx function does not create the specified key if the key does not exist in the registry. Certain registry operations perform access checks against the security descriptor of the key, not the access mask specified when the handle to the key was obtained. For example, even if a key is opened with a samDesired of KEY_READ, it can be used to create registry keys if the key's security descriptor permits. In contrast, the RegSetValueEx function specifically requires that the key be opened with the KEY_SET_VALUE access right. If your service or application impersonates different users, do not use this function with HKEY_CURRENT_USER. Instead, call the RegOpenCurrentUser function. Note that operations that access certain registry keys are redirected. For more information, see Registry Virtualization and 32-bit and 64-bit Application Data in the Registry. Examples For an example, see Deleting a Key with Subkeys. Requirements Minimum supported client Windows 2000 Professional [desktop apps only] Minimum supported server Windows 2000 Server [desktop apps only] Header Winreg.h (include Windows.h) Library Advapi32.lib DLL Advapi32.dll Unicode and ANSI names RegOpenKeyExW (Unicode) and RegOpenKeyExA (ANSI) See also RegCloseKey RegCreateKeyEx RegDeleteKey Registry Functions Registry Overview RegOpenKeyTransacted

 

	함수 RegEnumKeyEx
	LONG WINAPI RegEnumKeyEx(   _In_        HKEY      hKey,   _In_        DWORD     dwIndex,   _Out_       LPTSTR    lpName,   _Inout_     LPDWORD   lpcName,   _Reserved_  LPDWORD   lpReserved,   _Inout_     LPTSTR    lpClass,   _Inout_opt_ LPDWORD   lpcClass,   _Out_opt_   PFILETIME lpftLastWriteTime ); 특정 register key 하위 키들 열거하기. RegEnumKeyEx function Enumerates the subkeys of the specified open registry key. The function retrieves information about one subkey each time it is called. Syntax C++ Copy LONG WINAPI RegEnumKeyEx( _In_        HKEY      hKey, _In_        DWORD     dwIndex, _Out_       LPTSTR    lpName, _Inout_     LPDWORD   lpcName, _Reserved_  LPDWORD   lpReserved, _Inout_     LPTSTR    lpClass, _Inout_opt_ LPDWORD   lpcClass, _Out_opt_   PFILETIME lpftLastWriteTime ); Parameters hKey [in] A handle to an open registry key. The key must have been opened with the KEY_ENUMERATE_SUB_KEYS access right. For more information, see Registry Key Security and Access Rights. This handle is returned by the RegCreateKeyEx, RegCreateKeyTransacted, RegOpenKeyEx, or RegOpenKeyTransacted function. It can also be one of the following predefined keys: HKEY_CLASSES_ROOT HKEY_CURRENT_CONFIG HKEY_CURRENT_USER HKEY_LOCAL_MACHINE HKEY_PERFORMANCE_DATA HKEY_USERS dwIndex [in] The index of the subkey to retrieve. This parameter should be zero for the first call to the RegEnumKeyEx function and then incremented for subsequent calls. Because subkeys are not ordered, any new subkey will have an arbitrary index. This means that the function may return subkeys in any order. lpName [out] A pointer to a buffer that receives the name of the subkey, including the terminating null character. The function copies only the name of the subkey, not the full key hierarchy, to the buffer. If the function fails, no information is copied to this buffer. For more information, see Registry Element Size Limits. lpcName [in, out] A pointer to a variable that specifies the size of the buffer specified by the lpName parameter, in characters. This size should include the terminating null character. If the function succeeds, the variable pointed to by lpcName contains the number of characters stored in the buffer, not including the terminating null character. To determine the required buffer size, use the RegQueryInfoKey function to determine the size of the largest subkey for the key identified by the hKey parameter. lpReserved This parameter is reserved and must be NULL. lpClass [in, out] A pointer to a buffer that receives the user-defined class of the enumerated subkey. This parameter can be NULL. lpcClass [in, out, optional] A pointer to a variable that specifies the size of the buffer specified by the lpClass parameter, in characters. The size should include the terminating null character. If the function succeeds, lpcClass contains the number of characters stored in the buffer, not including the terminating null character. This parameter can be NULL only if lpClass is NULL. lpftLastWriteTime [out, optional] A pointer to FILETIME structure that receives the time at which the enumerated subkey was last written. This parameter can be NULL. Return value If the function succeeds, the return value is ERROR_SUCCESS. If the function fails, the return value is a system error code. If there are no more subkeys available, the function returns ERROR_NO_MORE_ITEMS. If the lpName buffer is too small to receive the name of the key, the function returns ERROR_MORE_DATA. Remarks To enumerate subkeys, an application should initially call the RegEnumKeyEx function with the dwIndex parameter set to zero. The application should then increment the dwIndex parameter and call RegEnumKeyEx until there are no more subkeys (meaning the function returns ERROR_NO_MORE_ITEMS). The application can also set dwIndex to the index of the last subkey on the first call to the function and decrement the index until the subkey with the index 0 is enumerated. To retrieve the index of the last subkey, use the RegQueryInfoKey function. While an application is using the RegEnumKeyEx function, it should not make calls to any registration functions that might change the key being enumerated. Note that operations that access certain registry keys are redirected. For more information, see Registry Virtualization and 32-bit and 64-bit Application Data in the Registry. Examples For an example, see Enumerating Registry Subkeys. Requirements Minimum supported client Windows 2000 Professional [desktop apps only] Minimum supported server Windows 2000 Server [desktop apps only] Header Winreg.h (include Windows.h) Library Advapi32.lib DLL Advapi32.dll Unicode and ANSI names RegEnumKeyExW (Unicode) and RegEnumKeyExA (ANSI) See also FILETIME RegCreateKeyEx RegDeleteKey Registry Functions Registry Overview RegOpenKeyEx RegQueryInfoKey

 

	함수 RegQueryValueEx
	LONG WINAPI RegQueryValueEx(   _In_        HKEY    hKey,   _In_opt_    LPCTSTR lpValueName,   _Reserved_  LPDWORD lpReserved,   _Out_opt_   LPDWORD lpType,   _Out_opt_   LPBYTE  lpData,   _Inout_opt_ LPDWORD lpcbData ); RegQueryValueEx function Retrieves the type and data for the specified value name associated with an open registry key. To ensure that any string values (REG_SZ, REG_MULTI_SZ, and REG_EXPAND_SZ) returned are null-terminated, use the RegGetValue function. Syntax C++ Copy LONG WINAPI RegQueryValueEx( _In_        HKEY    hKey, _In_opt_    LPCTSTR lpValueName, _Reserved_  LPDWORD lpReserved, _Out_opt_   LPDWORD lpType, _Out_opt_   LPBYTE  lpData, _Inout_opt_ LPDWORD lpcbData ); Parameters hKey [in] A handle to an open registry key. The key must have been opened with the KEY_QUERY_VALUE access right. For more information, see Registry Key Security and Access Rights. This handle is returned by the RegCreateKeyEx, RegCreateKeyTransacted, RegOpenKeyEx, or RegOpenKeyTransacted function. It can also be one of the following predefined keys: HKEY_CLASSES_ROOT HKEY_CURRENT_CONFIG HKEY_CURRENT_USER HKEY_LOCAL_MACHINE HKEY_PERFORMANCE_DATA HKEY_PERFORMANCE_NLSTEXT HKEY_PERFORMANCE_TEXT HKEY_USERS lpValueName [in, optional] The name of the registry value. If lpValueName is NULL or an empty string, "", the function retrieves the type and data for the key's unnamed or default value, if any. If lpValueName specifies a value that is not in the registry, the function returns ERROR_FILE_NOT_FOUND. Keys do not automatically have an unnamed or default value. Unnamed values can be of any type. For more information, see Registry Element Size Limits. lpReserved This parameter is reserved and must be NULL. lpType [out, optional] A pointer to a variable that receives a code indicating the type of data stored in the specified value. For a list of the possible type codes, see Registry Value Types. The lpType parameter can be NULL if the type code is not required. lpData [out, optional] A pointer to a buffer that receives the value's data. This parameter can be NULL if the data is not required. lpcbData [in, out, optional] A pointer to a variable that specifies the size of the buffer pointed to by the lpData parameter, in bytes. When the function returns, this variable contains the size of the data copied to lpData. The lpcbData parameter can be NULL only if lpData is NULL. If the data has the REG_SZ, REG_MULTI_SZ or REG_EXPAND_SZ type, this size includes any terminating null character or characters unless the data was stored without them. For more information, see Remarks. If the buffer specified by lpData parameter is not large enough to hold the data, the function returns ERROR_MORE_DATA and stores the required buffer size in the variable pointed to by lpcbData. In this case, the contents of the lpData buffer are undefined. If lpData is NULL, and lpcbData is non-NULL, the function returns ERROR_SUCCESS and stores the size of the data, in bytes, in the variable pointed to by lpcbData. This enables an application to determine the best way to allocate a buffer for the value's data. If hKey specifies HKEY_PERFORMANCE_DATA and the lpData buffer is not large enough to contain all of the returned data, RegQueryValueEx returns ERROR_MORE_DATA and the value returned through the lpcbData parameter is undefined. This is because the size of the performance data can change from one call to the next. In this case, you must increase the buffer size and call RegQueryValueEx again passing the updated buffer size in the lpcbData parameter. Repeat this until the function succeeds. You need to maintain a separate variable to keep track of the buffer size, because the value returned by lpcbData is unpredictable. If the lpValueName registry value does not exist, RegQueryValueEx returns ERROR_FILE_NOT_FOUND and the value returned through the lpcbData parameter is undefined. Return value If the function succeeds, the return value is ERROR_SUCCESS. If the function fails, the return value is a system error code. If the lpData buffer is too small to receive the data, the function returns ERROR_MORE_DATA. If the lpValueName registry value does not exist, the function returns ERROR_FILE_NOT_FOUND. Remarks An application typically calls RegEnumValue to determine the value names and then RegQueryValueEx to retrieve the data for the names. If the data has the REG_SZ, REG_MULTI_SZ or REG_EXPAND_SZ type, the string may not have been stored with the proper terminating null characters. Therefore, even if the function returns ERROR_SUCCESS, the application should ensure that the string is properly terminated before using it; otherwise, it may overwrite a buffer. (Note that REG_MULTI_SZ strings should have two terminating null characters.) One way an application can ensure that the string is properly terminated is to use RegGetValue, which adds terminating null characters if needed. If the data has the REG_SZ, REG_MULTI_SZ or REG_EXPAND_SZ type, and the ANSI version of this function is used (either by explicitly calling RegQueryValueExA or by not defining UNICODE before including the Windows.h file), this function converts the stored Unicode string to an ANSI string before copying it to the buffer pointed to by lpData. When calling the RegQueryValueEx function with hKey set to the HKEY_PERFORMANCE_DATA handle and a value string of a specified object, the returned data structure sometimes has unrequested objects. Do not be surprised; this is normal behavior. When calling the RegQueryValueEx function, you should always expect to walk the returned data structure to look for the requested object. Note that operations that access certain registry keys are redirected. For more information, see Registry Virtualization and 32-bit and 64-bit Application Data in the Registry. Examples Ensure that you reinitialize the value pointed to by the lpcbData parameter each time you call this function. This is very important when you call this function in a loop, as in the following code example. C++ Copy #include <windows.h> #include <malloc.h> #include <stdio.h> #define TOTALBYTES 8192 #define BYTEINCREMENT 4096 void main() { DWORD BufferSize = TOTALBYTES; DWORD cbData; DWORD dwRet; PPERF_DATA_BLOCK PerfData = (PPERF_DATA_BLOCK) malloc( BufferSize ); cbData = BufferSize; printf("\nRetrieving the data..."); dwRet = RegQueryValueEx( HKEY_PERFORMANCE_DATA, TEXT("Global"), NULL, NULL, (LPBYTE) PerfData, &cbData ); while( dwRet == ERROR_MORE_DATA ) { // Get a buffer that is big enough. BufferSize += BYTEINCREMENT; PerfData = (PPERF_DATA_BLOCK) realloc( PerfData, BufferSize ); cbData = BufferSize; printf("."); dwRet = RegQueryValueEx( HKEY_PERFORMANCE_DATA, TEXT("Global"), NULL, NULL, (LPBYTE) PerfData, &cbData ); } if( dwRet == ERROR_SUCCESS ) printf("\n\nFinal buffer size is %d\n", BufferSize); else printf("\nRegQueryValueEx failed (%d)\n", dwRet); } Requirements Minimum supported client Windows 2000 Professional [desktop apps only] Minimum supported server Windows 2000 Server [desktop apps only] Header Winreg.h (include Windows.h) Library Advapi32.lib DLL Advapi32.dll Unicode and ANSI names RegQueryValueExW (Unicode) and RegQueryValueExA (ANSI) See also ExpandEnvironmentStrings RegCreateKeyEx RegEnumKeyEx RegEnumValue RegGetValue Registry Functions Registry Overview RegOpenKeyEx RegQueryInfoKey

	함수 RegSetValueEx
	LONG WINAPI RegSetValueEx(   _In_             HKEY    hKey,   _In_opt_         LPCTSTR lpValueName,   _Reserved_       DWORD   Reserved,   _In_             DWORD   dwType,   _In_       const BYTE    *lpData,   _In_             DWORD   cbData ); RegSetValueEx function Sets the data and type of a specified value under a registry key. Syntax C++ Copy LONG WINAPI RegSetValueEx( _In_             HKEY    hKey, _In_opt_         LPCTSTR lpValueName, _Reserved_       DWORD   Reserved, _In_             DWORD   dwType, _In_       const BYTE    *lpData, _In_             DWORD   cbData ); Parameters hKey [in] A handle to an open registry key. The key must have been opened with the KEY_SET_VALUE access right. For more information, see Registry Key Security and Access Rights. This handle is returned by the RegCreateKeyEx, RegCreateKeyTransacted, RegOpenKeyEx, or RegOpenKeyTransacted function. It can also be one of the following predefined keys: HKEY_CLASSES_ROOT HKEY_CURRENT_CONFIG HKEY_CURRENT_USER HKEY_LOCAL_MACHINE HKEY_USERS The Unicode version of this function supports the following additional predefined keys: HKEY_PERFORMANCE_TEXT HKEY_PERFORMANCE_NLSTEXT lpValueName [in, optional] The name of the value to be set. If a value with this name is not already present in the key, the function adds it to the key. If lpValueName is NULL or an empty string, "", the function sets the type and data for the key's unnamed or default value. For more information, see Registry Element Size Limits. Registry keys do not have default values, but they can have one unnamed value, which can be of any type. Reserved This parameter is reserved and must be zero. dwType [in] The type of data pointed to by the lpData parameter. For a list of the possible types, see Registry Value Types. lpData [in] The data to be stored. For string-based types, such as REG_SZ, the string must be null-terminated. With the REG_MULTI_SZ data type, the string must be terminated with two null characters. String-literal values must be formatted using a backslash preceded by another backslash as an escape character. For example, specify "C:\\mydir\\myfile" to store the string "C:\mydir\myfile". Note  lpData indicating a null value is valid, however, if this is the case, cbData must be set to '0'.   cbData [in] The size of the information pointed to by the lpData parameter, in bytes. If the data is of type REG_SZ, REG_EXPAND_SZ, or REG_MULTI_SZ, cbData must include the size of the terminating null character or characters. Return value If the function succeeds, the return value is ERROR_SUCCESS. If the function fails, the return value is a nonzero error code defined in Winerror.h. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to get a generic description of the error. Remarks Value sizes are limited by available memory. However, storing large values in the registry can affect its performance. Long values (more than 2,048 bytes) should be stored as files, with the locations of the files stored in the registry. Application elements such as icons, bitmaps, and executable files should be stored as files and not be placed in the registry. If dwType is the REG_SZ, REG_MULTI_SZ, or REG_EXPAND_SZ type and the ANSI version of this function is used (either by explicitly calling RegSetValueExA or by not defining UNICODE before including the Windows.h file), the data pointed to by the lpData parameter must be an ANSI character string. The string is converted to Unicode before it is stored in the registry. Note that operations that access certain registry keys are redirected. For more information, see Registry Virtualization and 32-bit and 64-bit Application Data in the Registry. Requirements Minimum supported client Windows 2000 Professional [desktop apps only] Minimum supported server Windows 2000 Server [desktop apps only] Header Winreg.h (include Windows.h) Library Advapi32.lib DLL Advapi32.dll Unicode and ANSI names RegSetValueExW (Unicode) and RegSetValueExA (ANSI) See also RegCreateKeyEx RegFlushKey Registry Functions Registry Overview RegOpenKeyEx RegQueryValueEx

 

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