Platform SDK: Network Management

NetUserGetLocalGroups

The NetUserGetLocalGroups function retrieves a list of local groups to which a specified user belongs.

Security Requirements

Windows NT: Only authenticated users can successfully execute the NetUserGetLocalGroups function.

Windows 2000: If you call this function on a Windows 2000 domain controller that is running Active Directory, access is allowed or denied based on the access-control list (ACL) for the securable object. The default ACL permits all authenticated users and members of the "Pre-Windows 2000 compatible access" group to view the information. By default, the "Pre-Windows 2000 compatible access" group includes Everyone as a member. This enables anonymous access to the information if the system allows anonymous access.

If you call this function on a Windows 2000 member server or workstation, all authenticated users can view the information. Anonymous access is also permitted if the RestrictAnonymous policy setting allows anonymous access.

For more information about restricting anonymous access, see Security Requirements for the Network Management Functions.

NET_API_STATUS NetUserGetLocalGroups(
  LPCWSTR servername,    
  LPCWSTR username,      
  DWORD level,          
  DWORD flags,          
  LPBYTE *bufptr,       
  DWORD prefmaxlen,     
  LPDWORD entriesread,  
  LPDWORD totalentries  
);

Parameters

servername

[in] Pointer to a constant Unicode string specifying the name of the remote server on which the function is to execute. The string must begin with \\. If this parameter is NULL, the local computer is used.

username

[in] Pointer to a constant Unicode string specifying the name of the user for which to return local group membership information. If the string is of the form DomainName\UserName the user name is expected to be found on that domain. If the string is of the form UserName, the user name is expected to be found on the server specified by the servername parameter.

level

[in] Specifies the information level of the data. This parameter can be the following value.

Value	Meaning
0	Return the names of the local groups to which the user belongs. The bufptr parameter points to an array of LOCALGROUP_USERS_INFO_0 structures.

flags

[in] Specifies a bitmask of flags. Currently, only the value LG_INCLUDE_INDIRECT is defined. If this bit is set, the function also returns the names of the local groups in which the user is indirectly a member (that is, the user has membership in a global group that is itself a member of one or more local groups).

bufptr

[out] Pointer to the buffer that receives the data. The format of this data depends on the value of the level parameter. This buffer is allocated by the system and must be freed using the NetApiBufferFree function. Note that you must free the buffer even if the function fails with ERROR_MORE_DATA.

prefmaxlen

[in] Specifies the preferred maximum length of returned data, in bytes. If you specify MAX_PREFERRED_LENGTH, the function allocates the amount of memory required for the data. If you specify another value in this parameter, it can restrict the number of bytes that the function returns. If the buffer size is insufficient to hold all entries, the function returns ERROR_MORE_DATA. For more information, see Network Management Function Buffers and Network Management Function Buffer Lengths.

entriesread

[out] Pointer to a DWORD value that receives the count of elements actually enumerated.

totalentries

[out] Pointer to a DWORD value that receives the total number of entries that could have been enumerated.

Return Values

If the function succeeds, the return value is NERR_Success.

If the function fails, the return value can be one of the following error codes.

Value	Meaning
ERROR_ACCESS_DENIED	The user does not have access to the requested information.
ERROR_MORE_DATA	More entries are available. Specify a large enough buffer to receive all entries.
NERR_InvalidComputer	The computer name is invalid.
NERR_UserNotFound	The user name could not be found.

Remarks

To retrieve a list of global groups to which a specified user belongs, you can call the NetUserGetGroups function.

The following code sample demonstrates how to retrieve a list of the local groups to which a user belongs with a call to the NetUserGetLocalGroups function. The sample calls NetUserGetLocalGroups, specifying information level 0 (LOCALGROUP_USERS_INFO_0). The sample loops through the entries and prints the name of each local group in which the user has membership. If all available entries are not enumerated, it also prints the number of entries actually enumerated and the total number of entries available. Finally, the code sample frees the memory allocated for the information buffer.

#ifndef UNICODE
#define UNICODE
#endif

#include <stdio.h>
#include <assert.h>
#include <windows.h> 
#include <lm.h>

int wmain(int argc, wchar_t *argv[])
{
   LPLOCALGROUP_USERS_INFO_0 pBuf = NULL;
   DWORD dwLevel = 0;
   DWORD dwFlags = LG_INCLUDE_INDIRECT ;
   DWORD dwPrefMaxLen = -1;
   DWORD dwEntriesRead = 0;
   DWORD dwTotalEntries = 0;
   NET_API_STATUS nStatus;

   if (argc != 3)
   {
      fwprintf(stderr, L"Usage: %s \\\\ServerName UserName\n", argv[0]);
      exit(1);
   }
   //
   // Call the NetUserGetLocalGroups function 
   //  specifying information level 0.
   //
   //  The LG_INCLUDE_INDIRECT flag specifies that the 
   //   function should also return the names of the local 
   //   groups in which the user is indirectly a member.
   //
   nStatus = NetUserGetLocalGroups(argv[1],
                                   argv[2],
                                   dwLevel,
                                   dwFlags,
                                   (LPBYTE *) &pBuf,
                                   dwPrefMaxLen,
                                   &dwEntriesRead,
                                   &dwTotalEntries);
   //
   // If the call succeeds,
   //
   if (nStatus == NERR_Success)
   {
      LPLOCALGROUP_USERS_INFO_0 pTmpBuf;
      DWORD i;
      DWORD dwTotalCount = 0;

      if ((pTmpBuf = pBuf) != NULL)
      {
         fprintf(stderr, "\nLocal group(s):\n");
         //
         // Loop through the entries and 
         //  print the names of the local groups 
         //  to which the user belongs. 
         //
         for (i = 0; i < dwEntriesRead; i++)
         {
            assert(pTmpBuf != NULL);

            if (pTmpBuf == NULL)
            {
               fprintf(stderr, "An access violation has occurred\n");
               break;
            }

            wprintf(L"\t-- %s\n", pTmpBuf->lgrui0_name);

            pTmpBuf++;
            dwTotalCount++;
         }
      }
         //
         // If all available entries were
         //  not enumerated, print the number actually 
         //  enumerated and the total number available.
         //
      if (dwEntriesRead < dwTotalEntries)
         fprintf(stderr, "\nTotal entries: %d", dwTotalEntries);
      //
      // Otherwise, just print the total.
      //
      printf("\nEntries enumerated: %d\n", dwTotalCount);
   }
   else
      fprintf(stderr, "A system error has occurred: %d\n", nStatus);
   //
   // Free the allocated memory.
   //
   if (pBuf != NULL)
      NetApiBufferFree(pBuf);

   return 0;
}

If you are programming for Active Directory, you may be able to call certain Active Directory Service Interface (ADSI) methods to achieve the same functionality you can achieve by calling the network management user functions. For more information, see IADsUser and IADsComputer.

Requirements