Item

Description

Structure

VALENT.

Info

Contains information about a registry value.  The RegQueryMultipleValues() function uses this structure.

Definition

typedef struct value_ent {
  LPTSTR ve_valuename;
  DWORD ve_valuelen;
  DWORD_PTR ve_valueptr;
  DWORD ve_type;

} VALENT,
*PVALENT;

Members

ve_valuename

Pointer to a null-terminated string.  Before calling RegQueryMultipleValues(), set this member to point to the name of a value to retrieve.

ve_valuelen

Size of the data pointed to by ve_valueptr, in bytes.

ve_valueptr

Pointer to the data for the value entry.  This is a pointer to the value's data returned in the lpValueBuf buffer filled in by RegQueryMultipleValues().

ve_type

Type of data pointed to by ve_valueptr.

Header file

<windows.h>

Remark

Declared as Unicode and ANSI structures.

Table 1.

Item

Description

Structure

FILETIME.

Info

A 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601 (UTC).

Definition

typedef struct _FILETIME {
  DWORD dwLowDateTime;
  DWORD dwHighDateTime;

} FILETIME,
*PFILETIME;

Members

dwLowDateTime - Low-order part of the file time.

dwHighDateTime - High-order part of the file time.

Header file

<windows.h>

Remark

See below.

Table 2.

Item

Description

Structure

PDH_COUNTER_PATH_ELEMENTS.

Info

Contains the parsed elements of a fully qualified counter path.  The main purpose of this structure is to provide formatted text to the calling application for display.

Definition

typedef struct _PDH_COUNTER_PATH_ELEMENTS {
  LPTSTR szMachineName;
  LPTSTR szObjectName;
  LPTSTR szInstanceName;
  LPTSTR szParentInstance;
  DWORD dwInstanceIndex;
  LPTSTR szCounterName;

} PDH_COUNTER_PATH_ELEMENTS,
*PPDH_COUNTER_PATH_ELEMENTS;

Members

szMachineName - Pointer to a null-terminated string that specifies the computer name.

szObjectName - Pointer to a null-terminated string that specifies the object name.

szInstanceName - Pointer to a null-terminated string that specifies the instance name.

szParentInstance - Pointer to a null-terminated string that specifies the parent instance name.

dwInstanceIndex - Index of duplicate instance names.

szCounterName - Pointer to a null-terminated string that specifies the counter name.

Header file

<pdh.h>

Remark

Declared as Unicode and ANSI structures.

Table 3.

Item

Description

Structure

OSVERSIONINFO.

Info

Contains operating system version information.  The information includes major and minor version numbers, a build number, a platform identifier, and descriptive text about the operating system.  This structure is used with the GetVersionEx() function.  To obtain additional version information, see the OSVERSIONINFOEX structure.

Definition

typedef struct _OSVERSIONINFO {
  DWORD dwOSVersionInfoSize;
  DWORD dwMajorVersion;
  DWORD dwMinorVersion;
  DWORD dwBuildNumber;
  DWORD dwPlatformId;
  TCHAR szCSDVersion[128];

} OSVERSIONINFO;

Members

See below.

Header file

<windows.h>

Remark

Declared as Unicode and ANSI structures.  Relying on version information is not the best way to test for a feature.  Instead, refer to the documentation for the feature of interest.  If you must require a particular operating system, be sure to use it as a minimum supported version, rather than design the test for the one operating system.  This way, your detection code will continue to work on future versions of Windows.

Table 4.

Item

Description

Structure

OSVERSIONINFOEX.

Info

Contains operating system version information.  The information includes major and minor version numbers, a build number, a platform identifier, and information about product suites and the latest Service Pack installed on the system.  This structure is used with the GetVersionEx() and VerifyVersionInfo() functions.

Definition

typedef struct _OSVERSIONINFOEX {
  DWORD dwOSVersionInfoSize;
  DWORD dwMajorVersion;
  DWORD dwMinorVersion;
  DWORD dwBuildNumber;
  DWORD dwPlatformId;
  TCHAR szCSDVersion[128];
  WORD wServicePackMajor;
  WORD wServicePackMinor;
  WORD wSuiteMask;
  BYTE wProductType;
  BYTE wReserved;

} OSVERSIONINFOEX,
*POSVERSIONINFOEX,
*LPOSVERSIONINFOEX;

Members

See below.

Header file

<windows.h>

Remark

Declared as Unicode and ANSI structures.  Relying on version information is not the best way to test for a feature.  Instead, refer to the documentation for the feature of interest.  If you must require a particular operating system, be sure to use it as a minimum supported version, rather than design the test for the one operating system.  This way, your detection code will continue to work on future versions of Windows.  Note that you should not solely rely upon the VER_SUITE_SMALLBUSINESS flag to determine whether Small Business Server has been installed on the system, as both this flag and the VER_SUITE_SMALLBUSINESS_RESTRICTED flag are set when this product suite is installed.  If you upgrade this installation to Windows Server, Standard Edition, the VER_SUITE_SMALLBUSINESS_RESTRICTED flag will be unset however, the VER_SUITE_SMALLBUSINESS flag will remain set.  In this case, this indicates that Small Business Server was once installed on this system.  If this installation is further upgraded to Windows Server, Enterprise Edition, the VER_SUITE_SMALLBUSINESS key will remain set.  To determine whether a Win32-based application is running on WOW64, call the IsWow64Process() function.

Table 8.

Item

Description

Function

RegEnumKeyEx().

Use

Enumerates subkeys of the specified open registry key.  The function retrieves information about one subkey each time it is called.

Prototype

LONG RegEnumKeyEx(

  HKEY hKey,

  DWORD dwIndex,

  LPTSTR lpName,

  LPDWORD lpcName,

  LPDWORD lpReserved,

  LPTSTR lpClass,

  LPDWORD lpcClass,

  PFILETIME lpftLastWriteTime);

Parameters

hKey

[in] Handle to an open key.  The key must have been opened with the KEY_ENUMERATE_SUB_KEYS access right.  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_PERFORMANCE_DATA
HKEY_USERS

Windows Me/98/95:  This parameter can also be the following value:  HKEY_DYN_DATA

dwIndex

[in] 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] 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.

lpcName

[in, out] Pointer to a variable that specifies the size of the buffer specified by the lpName parameter, in TCHARs.  This size should include the terminating null character.  When the function returns, the variable pointed to by lpcName contains the number of characters stored in the buffer.  The count returned does not include the terminating null character.

lpReserved

Reserved; must be NULL.

lpClass

[in, out] Pointer to a buffer that receives the null-terminated class string of the enumerated subkey.  This parameter can be NULL.

lpcClass

[in, out] Pointer to a variable that specifies the size of the buffer specified by the lpClass parameter, in TCHARs.  The size should include the terminating null character.  When the function returns, lpcClass contains the number of characters stored in the buffer.  The count returned does not include the terminating null character.  This parameter can be NULL only if lpClass is NULL.

lpftLastWriteTime

[out] Pointer to a variable that receives the time at which the enumerated subkey was last written.

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.

Windows Server 2003, Windows NT/2000/XP:  If the lpName buffer is too small to receive the name of the key, the function returns ERROR_MORE_DATA.

Include file

<windows.h>

Remark

Implemented as Unicode and ANSI versions.  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.

Table 13.

Item

Description

Function

RegQueryInfoKey().

Use

Retrieves information about the specified registry key.

Prototype

LONG RegQueryInfoKey(

  HKEY hKey,

  LPTSTR lpClass,

  LPDWORD lpcClass,

  LPDWORD lpReserved,

  LPDWORD lpcSubKeys,

  LPDWORD lpcMaxSubKeyLen,

  LPDWORD lpcMaxClassLen,

  LPDWORD lpcValues,

  LPDWORD lpcMaxValueNameLen,

  LPDWORD lpcMaxValueLen,

  LPDWORD lpcbSecurityDescriptor,

  PFILETIME lpftLastWriteTime);

Parameters

hKey

[in] Handle to an open key.  The key must have been opened with the KEY_QUERY_VALUE access right.  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_PERFORMANCE_DATA
     HKEY_USERS

Windows Me/98/95:  This parameter can also be the following key: HKEY_DYN_DATA

lpClass

[out] Pointer to a buffer that receives the null-terminated class string of the key.  This parameter may be ignored.  This parameter can be NULL.

lpcClass

[in, out] Pointer to a variable that specifies the size of the buffer pointed to by the lpClass parameter, in TCHARs.  This size should include the terminating null character.  When the function returns, this variable contains the size of the class string stored in the buffer.  The count returned does not include the terminating null character.  If the buffer is not big enough, the function returns ERROR_MORE_DATA, and the variable contains the size of the string, in characters, without counting the null character.

If lpClass is NULL, lpcClass can be NULL.  Windows NT/2000/XP:  If the lpClass parameter is a valid address, but the lpcClass parameter is not (for example, it is NULL), the function returns ERROR_INVALID_PARAMETER.

Windows Me/98/95:  If the lpClass parameter is a valid address, but the lpcClass parameter is not (for example, it is NULL), the function returns ERROR_SUCCESS instead of ERROR_INVALID_PARAMETER. To ensure compatibility with other platforms, verify that lpcClass is valid before calling the function.

lpReserved

Reserved; must be NULL.

lpcSubKeys

[out] Pointer to a variable that receives the number of subkeys contained by the specified key.  This parameter can be NULL.

lpcMaxSubKeyLen

[out] Pointer to a variable that receives the size of the key's subkey with the longest name, in TCHARs.  This parameter can be NULL.

Windows NT/2000/XP:  The size does not include the terminating null character.

Windows Me/98/95:  The size includes the terminating null character.

lpcMaxClassLen

[out] Pointer to a variable that receives the size of the longest string specifying a subkey class, in TCHARs.  The count returned does not include the terminating null character.  This parameter can be NULL.

lpcValues

[out] Pointer to a variable that receives the number of values associated with the key.  This parameter can be NULL.

lpcMaxValueNameLen

[out] Pointer to a variable that receives the size of the key's longest value name, in TCHARs.  The size does not include the terminating null character.  This parameter can be NULL.

lpcMaxValueLen

[out] Pointer to a variable that receives the size of the longest data component among the key's values, in bytes.  This parameter can be NULL.

lpcbSecurityDescriptor

[out] Pointer to a variable that receives the size of the key's security descriptor, in bytes.  This parameter can be NULL.

lpftLastWriteTime

[out] Pointer to a FILETIME structure that receives the last write time. This parameter can be NULL.

Windows NT/2000/XP:  The function sets the members of the FILETIME structure to indicate the last time that the key or any of its value entries was modified.

Windows Me/98/95:  The function sets the members of the FILETIME structure to zero.  This is because the system does not keep track of registry key last write time information.

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.

Include file

<windows.h>

Remark

Implemented as Unicode and ANSI versions.

Table 14.

Item

Description

Function

RegEnumValue().

Use

Enumerates the values for the specified open registry key.  The function copies one indexed value name and data block for the key each time it is called.

Prototype

LONG RegEnumValue(

  HKEY hKey,

  DWORD dwIndex,

  LPTSTR lpValueName,

  LPDWORD lpcValueName,

  LPDWORD lpReserved,

  LPDWORD lpType,

  LPBYTE lpData,

  LPDWORD lpcbData);

Parameters

hKey

[in] Handle to an open key.  The key must have been opened with the KEY_QUERY_VALUE access right.  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_PERFORMANCE_DATA
HKEY_USERS

Windows Me/98/95:  This parameter can also be the following value: HKEY_DYN_DATA

dwIndex

[in] Index of the value to be retrieved.  This parameter should be zero for the first call to the RegEnumValue() function and then be incremented for subsequent calls.  Because values are not ordered, any new value will have an arbitrary index.  This means that the function may return values in any order.

lpValueName

[out] Pointer to a buffer that receives the name of the value, including the terminating null character.

lpcValueName

[in, out] Pointer to a variable that specifies the size of the buffer pointed to by the lpValueName parameter, in TCHARs.  This size should include the terminating null character.  When the function returns, the variable pointed to by lpcValueName contains the number of characters stored in the buffer.  The count returned does not include the terminating null character.

lpReserved

Reserved; must be NULL.

lpType

[out] Pointer to a variable that receives a code indicating the type of data stored in the specified value.  The lpType parameter can be NULL if the type code is not required.

lpData

[out] Pointer to a buffer that receives the data for the value entry.  This parameter can be NULL if the data is not required.  If lpData is NULL and lpcbData is non-NULL, the function 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 data.

lpcbData

[in, out] Pointer to a variable that specifies the size of the buffer pointed to by the lpData parameter, in bytes.  When the function returns, the variable pointed to by the lpcbData parameter contains the number of bytes stored in the buffer.  This parameter can be NULL only if lpData is NULL.  If the buffer specified by lpData 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 lpData are undefined.

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.

Include file

<windows.h>

Remark

Implemented as Unicode and ANSI versions.  To enumerate values, an application should initially call the RegEnumValue() function with the dwIndex parameter set to zero.  The application should then increment dwIndex and calls the RegEnumValue() function until there are no more values (until the function returns ERROR_NO_MORE_ITEMS).  The application can also set dwIndex to the index of the last value on the first call to the function and decrement the index until the value with index 0 is enumerated.  To retrieve the index of the last value, use the RegQueryInfoKey() function.  While using RegEnumValue(), an application should not call any registry functions that might change the key being queried.  To determine the maximum size of the name and data buffers, use the RegQueryInfoKey() function.

Table 15.

Item

Description

Function

PdhMakeCounterPath().

Use

Creates a full counter path using the members specified in the structure passed in the parameter list.

Prototype

PDH_STATUS PdhMakeCounterPath(

  PDH_COUNTER_PATH_ELEMENTS* pCounterPathElements,

  LPTSTR szFullPathBuffer,

  LPDWORD pcchBufferSize,

  DWORD dwFlags);

Parameters

See below.

Return value

See below.

Include file

<pdh.h>

Remark

Implemented as Unicode and ANSI versions.  The maximum length of a counter path is PDH_MAX_COUNTER_PATH, or 2,048 characters. PDH_MAX_COUNTER_PATH is defined in pdh.h.

Table 16.