MsiEnumClientsExA function (msi.h)
The MsiEnumClientsEx function enumerates the installed applications that use a specified component. The function retrieves a product code for an application each time it is called.
Windows Installer 4.5 or earlier: Not supported. This function is available beginning with Windows Installer 5.0.
Syntax
UINT MsiEnumClientsExA(
[in] LPCSTR szComponent,
[in, optional] LPCSTR szUserSid,
[in] DWORD dwContext,
[in] DWORD dwProductIndex,
[out, optional] CHAR [39] szProductBuf,
[out, optional] MSIINSTALLCONTEXT *pdwInstalledContext,
[out, optional] LPSTR szSid,
[in, out, optional] LPDWORD pcchSid
);
Parameters
[in] szComponent
The component code GUID that identifies the component. The function enumerates the applications that use this component.
[in, optional] szUserSid
A null-terminated string value that contains a security identifier (SID.) The enumeration of applications extends to users identified by this SID. The special SID string s-1-1-0 (Everyone) enumerates all applications for all users in the system. A SID value other than s-1-1-0 specifies a user SID for a particular user and enumerates the instances of applications installed by the specified user.
[in] dwContext
A flag that extends the enumeration to instances of applications installed in the specified installation context. The enumeration includes only instances of applications that are installed by the users identified by szUserSid.
This can be a combination of the following values.
[in] dwProductIndex
Specifies the index of the application to retrieve. The value of this parameter must be zero (0) in the first call to the function. For each subsequent call, the index must be incremented by 1. The index should only be incremented if the previous call to the function returns ERROR_SUCCESS.
[out, optional] szProductBuf
A string value that receives the product code for the application. The length of the buffer at this location should be large enough to hold a null-terminated string value containing the product code. The first 38 TCHAR characters receives the GUID for the component, and the 39th character receives a terminating NULL character.
[out, optional] pdwInstalledContext
A flag that gives the installation context of the application.
This can be a combination of the following values.
[out, optional] szSid
Receives the security identifier (SID) that identifies the user that installed the application. The location receives an empty string value if this instance of the application exists in a per-machine installation context.
The length of the buffer should be large enough to hold a null-terminated string value containing the SID. If the buffer is too small, the function returns ERROR_MORE_DATA and the location pointed to by pcchSid receives the number of TCHAR in the SID, not including the terminating NULL character.
If szSid is set to NULL and pcchSid is a valid pointer to a location in memory, the function returns ERROR_SUCCESS and the location receives the number of TCHAR in the SID, not including the terminating null character. The function can then be called again to retrieve the value, with the szSid buffer resized large enough to contain *pcchSid + 1 characters.
| SID type | Meaning |
|---|---|
|
The application is installed in a per-machine installation context. |
|
The SID for the user that installed the product. |
[in, out, optional] pcchSid
Pointer to a location in memory that contains a variable that specifies the number of TCHAR in the SID, not including the terminating null character. When the function returns, this variable is set to the size of the requested SID whether or not the function can successfully copy the SID and terminating null character into the buffer location pointed to by szSid. The size is returned as the number of TCHAR in the requested value, not including the terminating null character.
This parameter can be set to NULL only if szSid is also NULL, otherwise the function returns ERROR_INVALID_PARAMETER. If szSid and pcchSid are both set to NULL, the function returns ERROR_SUCCESS if the SID exists, without retrieving the SID value.
Return value
The MsiEnumClientsEx function returns one of the following values.
| Return code | Description |
|---|---|
|
Administratator privileges are required to enumerate components of applications installed by users other than the current user. |
|
The configuration data is corrupt. |
|
An invalid parameter is passed to the function. |
|
There are no more applications to enumerate. |
|
The function succeeded. |
|
The provided buffer was too small to hold the entire value. |
|
The function failed. |
Remarks
Note
The msi.h header defines MsiEnumClientsEx as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Installer 5.0 on Windows Server 2012, Windows 8, Windows Server 2008 R2 or Windows 7. See the Windows Installer Run-Time Requirements for information about the minimum Windows service pack that is required by a Windows Installer version. |
| Target Platform | Windows |
| Header | msi.h |
| Library | Msi.lib |
| DLL | Msi.dll |
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