How to retrieve currently logged in username in Windows? - windows

Question

I wish to retrieve the username of the currently logged in user in Windows (preferably some solution that works from Windows XP to W10) in a Delphi 7 project.
I tried both solutions given in this question, but they all give the name of the user, not the actual "username" that is used to log into Windows.
For example, the "username" I use to log into Windows is "joao.victor" (using a local Windows account), or my e-mail when I use a Microsoft account. But when I tried those 2 solutions, the string it returned was "João", which is my first name and the name configured in those accounts.
Does anyone know of a solution where I can retrieve the username that is used to log into Windows instead of the first name of the user?

Answer 1

Have you tried this?
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(GetCurrentUserName);
end;
function TForm1.GetCurrentUserName: string;
const
cnMaxUserNameLen = 254;
var
sUserName: string;
dwUserNameLen: DWORD;
begin
dwUserNameLen := cnMaxUserNameLen - 1;
SetLength(sUserName, cnMaxUserNameLen);
GetUserName(PChar(sUserName), dwUserNameLen);
SetLength(sUserName, dwUserNameLen);
Result := sUserName;
end;
or alternatively
function UserName: String;
var User: PChar;
i: DWord;
begin
i := 1024;
user := StrAlloc(Succ(i));
if GetUserName(User, i) then
Result := StrPas(User)
else
Result := 'unknown';
end;
These 2 functions return the username you see on Windows login
See GetUserName

Answer 2

GetUserNameEx is the most flexible, and offers various user names depending on the context and format you're looking to obtain. I don't know if it works in XP, but it does in Windows 2000 and up (tested up to Windows 7, Server 2008 and Windows Server 2012).
Here's a sample console app that has some type definitions that will help, along with the function declaration and sample code that demonstrates the possibilities. It compiles in both D2007 and Seattle/Berlin.
program Project1;
{$APPTYPE CONSOLE}
uses
System.SysUtils, WinAPI.Windows;
type
EXTENDED_NAME_FORMAT = DWORD;
const
NameUnknown = 0;
NameFullyQualifiedDN = 1;
NameSamCompatible = 2;
NameDisplay = 3;
NameUniqueId = 6;
NameCanonical = 7;
NameUserPrincipal = 8;
NameCanonicalEx = 9;
NameServicePrincipal = 10;
NameDnsDomain = 12;
const
NameFormats: array[0..8] of EXTENDED_NAME_FORMAT = (NameFullyQualifiedDN,
NameSamCompatible,
NameDisplay,
NameUniqueID,
NameCanonical,
NameUserPrincipal,
NameCanonicalEx,
NameServicePrincipal,
NameDnsDomain);
function GetUserNameExW(NameFormat: EXTENDED_NAME_FORMAT; lpNameBuffer: LPWSTR;
var nSize: ULONG): BOOL; stdcall;
external 'secur32.dll' Name 'GetUserNameExW';
var
UserName: String;
Size: ULONG;
i: Integer;
begin
for i := Low(NameFormats) to High(NameFormats) do
begin
Size := 0;
GetUserNameExW(NameFormats[i], nil, Size);
SetLength(UserName, Size);
if GetUserNameExW(NameFormats[i], PWideChar(UserName), Size) then
WriteLn(Ord(NameFormats[i]), #32 + UserName);
end;
ReadLn;
end.

Answer 3

Short answer: use wmic. Long answer check my answer at https://stackoverflow.com/a/58377194/3584693

Answer 4

With LUA and RunAs and whatnot this is far more complicated than it seems..
But the oldest and simplest trick still works even when switching accounts.
in pre Server 2003 use:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersioin\Winlogon DefaultUserName
and above:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI LastLoggedOnSAMUser
LastLoggedOnSAMUser will be in format DOMAIN\USERNAME where a local domain can be a Period.

Answer 5

i don't have windows XP to test it but i tried it on delphi 7 and delphi 10 Seattle
ShowMessage(GetEnvironmentVariable('USERNAME'));