Looking Up a User's Full Name

Computers can be organized into a domain, which is a collection of computers network. The domain administrator maintains centralized user and group account information.

To find the full name of a user, given the user name and domain name:

  • Convert the user name and domain name to Unicode, if they are not already Unicode strings.
  • Look up the computer name of the domain controller (DC) by calling NetGetDCName.
  • Look up the user name on the DC computer by calling NetUserGetInfo.
  • Convert the full user name to ANSI, unless the program is expecting to work with Unicode strings.

The following sample code is a function (GetFullName) that takes a user name and a domain name in the first two arguments and returns the user's full name in the third argument.

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

#pragma comment(lib, "netapi32.lib")

BOOL GetFullName( char *UserName, char *Domain, char *dest )
    WCHAR wszUserName[UNLEN+1];          // Unicode user name
    WCHAR wszDomain[256]; 
    LPBYTE ComputerName;
//    struct _SERVER_INFO_100 *si100;  // Server structure
    struct _USER_INFO_2 *ui;         // User structure

// Convert ANSI user name and domain to Unicode

    MultiByteToWideChar( CP_ACP, 0, UserName,
        (int) strlen(UserName)+1, wszUserName, 
        sizeof(wszUserName)/sizeof(WCHAR) );

    MultiByteToWideChar( CP_ACP, 0, Domain,
        (int) strlen(Domain)+1, wszDomain, 
        sizeof(wszDomain)/sizeof(WCHAR) );

// Get the computer name of a DC for the domain.

    NetGetDCName( NULL, wszDomain, &ComputerName );

// Look up the user on the DC.

    if( NetUserGetInfo( (LPWSTR) ComputerName,
        (LPWSTR) &wszUserName, 2, (LPBYTE *) &ui ) )
        wprintf( L"Error getting user information.\n" );
        return( FALSE );

// Convert the Unicode full name to ANSI.

    WideCharToMultiByte( CP_ACP, 0, ui->usri2_full_name, -1,
        dest, 256, NULL, NULL );

    return (TRUE);