WNetGetUserA function (winnetwk.h)

Article
02/09/2023

The WNetGetUser function retrieves the current default user name, or the user name used to establish a network connection.

Syntax

DWORD WNetGetUserA(
  [in]      LPCSTR  lpName,
  [out]     LPSTR   lpUserName,
  [in, out] LPDWORD lpnLength
);

Parameters

[in] lpName

A pointer to a constant null-terminated string that specifies either the name of a local device that has been redirected to a network resource, or the remote name of a network resource to which a connection has been made without redirecting a local device.

If this parameter is NULL or the empty string, the system returns the name of the current user for the process.

[out] lpUserName

A pointer to a buffer that receives the null-terminated user name.

[in, out] lpnLength

A pointer to a variable that specifies the size of the lpUserName buffer, in characters. If the call fails because the buffer is not large enough, this variable contains the required buffer size.

Return value

If the function succeeds, the return value is NO_ERROR.

If the function fails, the return value is a system error code, such as one of the following values.

Return code	Description
ERROR_NOT_CONNECTED	The device specified by the lpName parameter is not a redirected device or a connected network name.
ERROR_MORE_DATA	More entries are available with subsequent calls.
ERROR_NO_NETWORK	The network is unavailable.
ERROR_EXTENDED_ERROR	A network-specific error occurred. To obtain a description of the error, call the WNetGetLastError function.
ERROR_NO_NET_OR_BAD_PATH	None of the providers recognize the local name as having a connection. However, the network is not available for at least one provider to whom the connection may belong.

Remarks

The WNetGetUser function is not aware of shares on the Distributed File System (DFS). If the name specified by the lpName parameter is a local device redirected to a DFS share or a remote resource that represents a DFS share, the WNetGetUser function fails with ERROR_NOT_CONNECTED.

Examples

The following code sample illustrates how to use the WNetGetUser function to retrieve the name of the user associated with a redirected local device or a remote network resource.

#ifndef UNICODE
#define UNICODE
#endif
#pragma comment(lib, "mpr.lib")

#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <Winnetwk.h>

int wmain(int argc, wchar_t * argv[])
{
    DWORD dwRetVal;

    WCHAR UserName[MAX_PATH];

    DWORD dwNameLength = MAX_PATH;

    if (argc != 2) {
        wprintf
            (L"Usage: %s [Redirected-LocalDevice or Network-Resource-Remote-name\n",
             argv[0]);
        exit(1);
    }

    wprintf(L"Calling WNetGetUser with Network-Resource = %s\n", argv[1]);

    dwRetVal = WNetGetUser(argv[1], UserName, &dwNameLength);
    //
    // If the call succeeds, print the user information.
    //
    if (dwRetVal == NO_ERROR) {

        wprintf(L"WNetGetUser returned success\n");
        wprintf(L"\tUsername=%s   NameLength=%d\n", &UserName, dwNameLength);
        exit(0);
    }

    else {
        wprintf(L"WNetGetUser failed with error: %u\n", dwRetVal);
        exit(1);
    }
}

Note

The winnetwk.h header defines WNetGetUser 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 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	winnetwk.h
Library	Mpr.lib
DLL	Mpr.dll