FreePascal: How to use GetEnvironmentVariable in non-latin Windows? - windows

Question

I've been writing some code using Lazarus 1.6.4 and FPC 3.0.2 to get USERNAME in Windows and USER in Linux. To achieve this I used SysUtils.GetEnvironmentVariable function. In Linux it works perfect, but in Windows it returns something corrupted that looks like UTF8 string opened in wrong encoding. My USERNAME in Windows has Cyrillic symbols so instead of the actual name GetEnvironmentVariable returns ???????? but it should be Пользователь.
Here my code:
function GetUserName: string;
{$IFDEF MSWINDOWS}
const
envVar = 'USERNAME';
{$ENDIF}
{$IFDEF UNIX}
envVar = 'USER';
{$ENDIF}
begin
Result := SysUtils.GetEnvironmentVariable(envVar);
{$IFDEF MSWINDOWS}
{ TODO : BUG: Does not work correct for non-latin strings }
Result := LazUTF8.UTF8ToWinCP(Result)
{$ENDIF}
end;
And it returns corrupted strings when it contains non-latain symbols inside.
How can I GetEnvironmentVariable in correct encoding in Windows OS?

Answer 1

Afaik in 3.0+ getenvironmentvariable is overloaded for unicodestring on windows, and that uses the -W variant.
var res,tag : unicodestring;
begin
tag:='HOME';
res:=getenvironmentvariable(tag);
end;
Just
getenvironmentstring (unicodestring('whatever'));
might also work, but make sure you either set utf8 as default encoding, or assign the result to an unicodestring.

Answer 2

After a day run I found the solution that work for me. You should use Unicode version of SysUtils.GetEnvironmentVariable and convert the result to the Windows current code page. Here the code below:
uses
{$IFDEF MSWINDOWS}
LazUTF8
{$ENDIF}
;
function GetUserName: string;
const
envVar: UnicodeString =
{$IFDEF MSWINDOWS}
'USERNAME'
{$ENDIF}
{$IFDEF UNIX}
'USER'
{$ENDIF};
begin
// USE Unicode String Version only!
Result := SysUtils.GetEnvironmentVariable(envVar);
{$IFDEF MSWINDOWS}
Result := LazUTF8.UTF8ToWinCP(Result)
{$ENDIF}
end;
UPDATE 01.12.2017
My Solution depends on ENV as David mentioned in comments. During the discussion I found more reliable solution here. The code below:
function GetCurrentUserName: String;
{$IFDEF WINDOWS}
const
MaxLen = 256;
var
Len: DWORD;
WS: WideString;
Res: windows.BOOL;
{$ENDIF}
begin
Result := '';
{$IFDEF UNIX}
{$IF (DEFINED(LINUX)) OR (DEFINED(FREEBSD))}
Result := SysToUtf8(GetUserName(fpgetuid)); //GetUsername in unit Users, fpgetuid in unit BaseUnix
{$ELSE Linux/BSD}
Result := GetEnvironmentVariableUtf8('USER');
{$ENDIF UNIX}
{$ELSE}
{$IFDEF WINDOWS}
Len := MaxLen;
{$IFnDEF WINCE}
if Win32MajorVersion <= 4 then
begin
SetLength(Result,MaxLen);
Res := Windows.GetuserName(#Result[1], Len);
//writeln('GetUserNameA = ',Res);
if Res then
begin
SetLength(Result,Len-1);
Result := SysToUtf8(Result);
end
else SetLength(Result,0);
end
else
{$ENDIF NOT WINCE}
begin
SetLength(WS, MaxLen-1);
Res := Windows.GetUserNameW(#WS[1], Len);
//writeln('GetUserNameW = ',Res);
if Res then
begin
SetLength(WS, Len - 1);
Result := Utf16ToUtf8(WS);
end
else SetLength(Result,0);
end;
{$ENDIF WINDOWS}
{$ENDIF UNIX}
end;