Retrieves the name of the user or other security principal associated with the calling thread. You can specify the format of the returned name.

If the thread is impersonating a client, GetUserNameEx returns the name of the client.

Syntax

BOOLEAN WINAPI GetUserNameEx(
  __in     EXTENDED_NAME_FORMAT NameFormat,
  __out    LPTSTR lpNameBuffer,
  __inout  PULONG lpnSize
);

Parameters

NameFormat [in]

The format of the name. This parameter is a value from the EXTENDED_NAME_FORMAT enumeration type. It cannot be NameUnknown. If the user account is not in a domain, only NameSamCompatible is supported.

lpNameBuffer [out]

A pointer to a buffer that receives the name in the specified format. The buffer must include space for the terminating null character.

lpnSize [in, out]

On input, this variable specifies the size of the lpNameBuffer buffer, in TCHARs. If the function is successful, the variable receives the number of TCHARs copied to the buffer, not including the terminating null character.

If lpNameBuffer is too small, the function fails and GetLastError returns ERROR_MORE_DATA. This parameter receives the required buffer size, in Unicode characters (whether or not Unicode is being used), including the terminating null character.

If this parameter is greater than 32767, the function fails and GetLastError returns ERROR_MORE_DATA.

Return Value

If the function succeeds, the return value is a nonzero value.

If the function fails, the return value is zero. To get extended error information, call GetLastError. Possible values include the following.

Requirements

See Also

EXTENDED_NAME_FORMAT

LookupAccountName

System Information Functions

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Build date: 11/19/2009