unit MiniReg;
{
 lightweight replacement for TRegistry. Does not use Classes or SysUtils. Intended
 for space-limited applets where only the commonly used functions are necessary.
 Returns True if Successful, else False.
 Written by Ben Hochstrasser (<a href="mailto:bhoc@surfeu.ch">bhoc@surfeu.ch</a>).
 This code is GPL.
}
// Function Examples:
 procedure TForm1.Button1Click(Sender: TObject);
 var
  ba1, ba2: array of byte;
  n: integer;
  s: String;
  d: Cardinal;
 begin
  setlength(ba1, 10);
  for n := 0 to 9 do ba1[n] := byte(n);
  RegSetString(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestString', 'TestMe');
  RegSetExpandString(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestExpandString',
  '%SystemRoot%\Test');
  RegSetMultiString(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestMultiString',
  'String1'#0'String2'#0'String3');
  RegSetDword(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestDword', 7);
  RegSetBinary(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestBinary', ba1);
  RegGetString(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestString', s);
  RegGetMultiString(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestMultiString', s);
  RegGetExpandString(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestExpandString', s);
  RegGetDWORD(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestDword', d);
  RegGetBinary(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestBinary', s);
  SetLength(ba2, Length(s));
  for n := 1 to Length(s) do ba2[n-1] := byte(s[n]);
  Button1.Caption := IntToStr(Length(ba2));
  if RegKeyExists(HKEY_CURRENT_USER, 'Software\My Company\Test\foo') then
  if RegValueExists(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestBinary') then
  MessageBox(GetActiveWindow, 'OK', 'OK', MB_OK);
  RegDelValue(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar\TestString');
  RegDelKey(HKEY_CURRENT_USER, 'Software\My Company\Test\foo\bar');
  RegDelKey(HKEY_CURRENT_USER, 'Software\My Company\Test\foo');
  RegDelKey(HKEY_CURRENT_USER, 'Software\My Company\Test');
  RegDelKey(HKEY_CURRENT_USER, 'Software\My Company');
  if RegEnumKeys(HKEY_CURRENT_USER, 'Software\My Company', s) then
  ListBox1.Text := s;
  if RegEnumValues(HKEY_CURRENT_USER, 'Software\My Company', s) then
  ListBox1.Text := s;
  if RegConnect('\\server1', HKEY_LOCAL_MACHINE, RemoteKey) then
  begin
  RegGetString(RemoteKey, 'Software\My Company\Test\foo\bar\TestString', s);
  RegDisconnect(RemoteKey);
  end;
 end;

interface
uses Windows;
function RegSetString(RootKey: HKEY; Name: String; Value: String): boolean;
function RegSetMultiString(RootKey: HKEY; Name: String; Value: String): boolean;
function RegSetExpandString(RootKey: HKEY; Name: String; Value: String): boolean;
function RegSetDWORD(RootKey: HKEY; Name: String; Value: Cardinal): boolean;
function RegSetBinary(RootKey: HKEY; Name: String; Value: Array of Byte): boolean;
function RegGetString(RootKey: HKEY; Name: String; Var Value: String): boolean;
function RegGetMultiString(RootKey: HKEY; Name: String; Var Value: String): boolean;
function RegGetExpandString(RootKey: HKEY; Name: String; Var Value: String): boolean;
function RegGetDWORD(RootKey: HKEY; Name: String; Var Value: Cardinal): boolean;
function RegGetBinary(RootKey: HKEY; Name: String; Var Value: String): boolean;
function RegGetValueType(RootKey: HKEY; Name: String; var Value: Cardinal): boolean;
function RegValueExists(RootKey: HKEY; Name: String): boolean;
function RegKeyExists(RootKey: HKEY; Name: String): boolean;
function RegDelValue(RootKey: HKEY; Name: String): boolean;
function RegDelKey(RootKey: HKEY; Name: String): boolean;
function RegConnect(MachineName: String; RootKey: HKEY; var RemoteKey: HKEY): boolean;
function RegDisconnect(RemoteKey: HKEY): boolean;
function RegEnumKeys(RootKey: HKEY; Name: String; var KeyList: String): boolean;
function RegEnumValues(RootKey: HKEY; Name: String; var ValueList: String): boolean;
implementation
function LastPos(Needle: Char; Haystack: String): integer;
begin
 for Result := Length(Haystack) downto 1 do
  if Haystack[Result] = Needle then
  Break;
end;
function RegConnect(MachineName: String; RootKey: HKEY; var RemoteKey: HKEY): boolean;
begin
 Result := (RegConnectRegistry(PChar(MachineName), RootKey, RemoteKey) = ERROR_SUCCESS);
end;
function RegDisconnect(RemoteKey: HKEY): boolean;
begin
 Result := (RegCloseKey(RemoteKey) = ERROR_SUCCESS);
end;
function RegSetValue(RootKey: HKEY; Name: String; ValType: Cardinal; PVal: Pointer; ValSize: Cardinal): boolean;
var
 SubKey: String;
 n: integer;
 dispo: DWORD;
 hTemp: HKEY;
begin
 Result := False;
 n := LastPos('\', Name);
 if n > 0 then
 begin
  SubKey := Copy(Name, 1, n - 1);
  if RegCreateKeyEx(RootKey, PChar(SubKey), 0, nil, REG_OPTION_NON_VOLATILE, KEY_WRITE,
  nil, hTemp, @dispo) = ERROR_SUCCESS then
  begin
  SubKey := Copy(Name, n + 1, Length(Name) - n);
  Result := (RegSetValueEx(hTemp, PChar(SubKey), 0, ValType, PVal, ValSize) = ERROR_SUCCESS);
  RegCloseKey(hTemp);
  end;
 end;
end;
function RegGetValue(RootKey: HKEY; Name: String; ValType: Cardinal; var PVal: Pointer;
 var ValSize: Cardinal): boolean;
var
 SubKey: String;
 n: integer;
 MyValType: DWORD;
 hTemp: HKEY;
 Buf: Pointer;
 BufSize: Cardinal;
begin
 Result := False;
 n := LastPos('\', Name);
 if n > 0 then
 begin
  SubKey := Copy(Name, 1, n - 1);
  if RegOpenKeyEx(RootKey, PChar(SubKey), 0, KEY_READ, hTemp) = ERROR_SUCCESS then
  begin
  SubKey := Copy(Name, n + 1, Length(Name) - n);
  if RegQueryValueEx(hTemp, PChar(SubKey), nil, @MyValType, nil, @BufSize) = ERROR_SUCCESS then
  begin
  GetMem(Buf, BufSize);
  if RegQueryValueEx(hTemp, PChar(SubKey), nil, @MyValType, Buf, @BufSize) = ERROR_SUCCESS then
  begin
  if ValType = MyValType then
  begin
  PVal := Buf;
  ValSize := BufSize;
  Result := True;
  end else
  begin
  FreeMem(Buf);
  end;
  end else
  begin
  FreeMem(Buf);
  end;
  end;
  RegCloseKey(hTemp);
  end;
 end;
end;
function RegSetString(RootKey: HKEY; Name: String; Value: String): boolean;
begin
 Result := RegSetValue(RootKey, Name, REG_SZ, PChar(Value + #0), Length(Value) + 1);
end;
function RegSetMultiString(RootKey: HKEY; Name: String; Value: String): boolean;
begin
 Result := RegSetValue(RootKey, Name, REG_MULTI_SZ, PChar(Value + #0#0), Length(Value) + 2);
end;
function RegSetExpandString(RootKey: HKEY; Name: String; Value: String): boolean;
begin
 Result := RegSetValue(RootKey, Name, REG_EXPAND_SZ, PChar(Value + #0), Length(Value) + 1);
end;
function RegSetDword(RootKey: HKEY; Name: String; Value: Cardinal): boolean;
begin
 Result := RegSetValue(RootKey, Name, REG_DWORD, @Value, SizeOf(Cardinal));
end;
function RegSetBinary(RootKey: HKEY; Name: String; Value: Array of Byte): boolean;
begin
 Result := RegSetValue(RootKey, Name, REG_BINARY, @Value[Low(Value)], length(Value));
end;
function RegGetString(RootKey: HKEY; Name: String; Var Value: String): boolean;
var
 Buf: Pointer;
 BufSize: Cardinal;
begin
 Result := False;
 if RegGetValue(RootKey, Name, REG_SZ, Buf, BufSize) then
 begin
  Dec(BufSize);
  SetLength(Value, BufSize);
  if BufSize > 0 then
  CopyMemory(@Value[1], Buf, BufSize);
  FreeMem(Buf);
  Result := True;
 end;
end;
function RegGetMultiString(RootKey: HKEY; Name: String; Var Value: String): boolean;
var
 Buf: Pointer;
 BufSize: Cardinal;
begin
 Result := False;
 if RegGetValue(RootKey, Name, REG_MULTI_SZ, Buf, BufSize) then
 begin
  Dec(BufSize);
  SetLength(Value, BufSize);
  if BufSize > 0 then
  CopyMemory(@Value[1], Buf, BufSize);
  FreeMem(Buf);
  Result := True;
 end;
end;
function RegGetExpandString(RootKey: HKEY; Name: String; Var Value: String): boolean;
var
 Buf: Pointer;
 BufSize: Cardinal;
begin
 Result := False;
 if RegGetValue(RootKey, Name, REG_EXPAND_SZ, Buf, BufSize) then
 begin
  Dec(BufSize);
  SetLength(Value, BufSize);
  if BufSize > 0 then
  CopyMemory(@Value[1], Buf, BufSize);
  FreeMem(Buf);
  Result := True;
 end;
end;
function RegGetDWORD(RootKey: HKEY; Name: String; Var Value: Cardinal): boolean;
var
 Buf: Pointer;
 BufSize: Cardinal;
begin
 Result := False;
 if RegGetValue(RootKey, Name, REG_DWORD, Buf, BufSize) then
 begin
  CopyMemory(@Value, Buf, BufSize);
  FreeMem(Buf);
  Result := True;
 end;
end;
function RegGetBinary(RootKey: HKEY; Name: String; Var Value: String): boolean;
var
 Buf: Pointer;
 BufSize: Cardinal;
begin
 Result := False;
 if RegGetValue(RootKey, Name, REG_BINARY, Buf, BufSize) then
 begin
  SetLength(Value, BufSize);
  CopyMemory(@Value[1], Buf, BufSize);
  FreeMem(Buf);
  Result := True;
 end;
end;
function RegValueExists(RootKey: HKEY; Name: String): boolean;
var
 SubKey: String;
 n: integer;
 hTemp: HKEY;
begin
 Result := False;
 n := LastPos('\', Name);
 if n > 0 then
 begin
  SubKey := Copy(Name, 1, n - 1);
  if RegOpenKeyEx(RootKey, PChar(SubKey), 0, KEY_READ, hTemp) = ERROR_SUCCESS then
  begin
  SubKey := Copy(Name, n + 1, Length(Name) - n);
  Result := (RegQueryValueEx(hTemp, PChar(SubKey), nil, nil, nil, nil) = ERROR_SUCCESS);
  RegCloseKey(hTemp);
  end;
 end;
end;
function RegGetValueType(RootKey: HKEY; Name: String; var Value: Cardinal): boolean;
var
 SubKey: String;
 n: integer;
 hTemp: HKEY;
 ValType: Cardinal;
begin
 Result := False;
 Value := REG_NONE;
 n := LastPos('\', Name);
 if n > 0 then
 begin
  SubKey := Copy(Name, 1, n - 1);
  if (RegOpenKeyEx(RootKey, PChar(SubKey), 0, KEY_READ, hTemp) = ERROR_SUCCESS) then
  begin
  SubKey := Copy(Name, n + 1, Length(Name) - n);
  Result := (RegQueryValueEx(hTemp, PChar(SubKey), nil, @ValType, nil, nil) = ERROR_SUCCESS);
  if Result then
  Value := ValType;
  RegCloseKey(hTemp);
  end;
 end;
end;
function RegKeyExists(RootKey: HKEY; Name: String): boolean;
var
 SubKey: String;
 n: integer;
 hTemp: HKEY;
begin
 Result := False;
 n := LastPos('\', Name);
 if n > 0 then
 begin
  SubKey := Copy(Name, 1, n - 1);
  if RegOpenKeyEx(RootKey, PChar(SubKey), 0, KEY_READ, hTemp) = ERROR_SUCCESS then
  begin
  Result := True;
  RegCloseKey(hTemp);
  end;
 end;
end;
function RegDelValue(RootKey: HKEY; Name: String): boolean;
var
 SubKey: String;
 n: integer;
 hTemp: HKEY;
begin
 Result := False;
 n := LastPos('\', Name);
 if n > 0 then
 begin
  SubKey := Copy(Name, 1, n - 1);
  if RegOpenKeyEx(RootKey, PChar(SubKey), 0, KEY_WRITE, hTemp) = ERROR_SUCCESS then
  begin
  SubKey := Copy(Name, n + 1, Length(Name) - n);
  Result := (RegDeleteValue(hTemp, PChar(SubKey)) = ERROR_SUCCESS);
  RegCloseKey(hTemp);
  end;
 end;
end;
function RegDelKey(RootKey: HKEY; Name: String): boolean;
var
 SubKey: String;
 n: integer;
 hTemp: HKEY;
begin
 Result := False;
 n := LastPos('\', Name);
 if n > 0 then
 begin
  SubKey := Copy(Name, 1, n - 1);
  if RegOpenKeyEx(RootKey, PChar(SubKey), 0, KEY_WRITE, hTemp) = ERROR_SUCCESS then
  begin
  SubKey := Copy(Name, n + 1, Length(Name) - n);
  Result := (RegDeleteKey(hTemp, PChar(SubKey)) = ERROR_SUCCESS);
  RegCloseKey(hTemp);
  end;
 end;
end;
function RegEnum(RootKey: HKEY; Name: String; var ResultList: String; const DoKeys: Boolean): boolean;
var
 i: integer;
 iRes: integer;
 s: String;
 hTemp: HKEY;
 Buf: Pointer;
 BufSize: Cardinal;
begin
 Result := False;
 ResultList := '';
 if RegOpenKeyEx(RootKey, PChar(Name), 0, KEY_READ, hTemp) = ERROR_SUCCESS then
 begin
  Result := True;
  BufSize := 1024;
  GetMem(buf, BufSize);
  i := 0;
  iRes := ERROR_SUCCESS;
  while iRes = ERROR_SUCCESS do
  begin
  BufSize := 1024;
  if DoKeys then
  iRes := RegEnumKeyEx(hTemp, i, buf, BufSize, nil, nil, nil, nil)
  else
  iRes := RegEnumValue(hTemp, i, buf, BufSize, nil, nil, nil, nil);
  if iRes = ERROR_SUCCESS then
  begin
  SetLength(s, BufSize);
  CopyMemory(@s[1], buf, BufSize);
  if ResultList = '' then
  ResultList := s
  else
  ResultList := Concat(ResultList, #13#10, s);
  inc(i);
  end;
  end;
  FreeMem(buf);
  RegCloseKey(hTemp);
 end;
end;
function RegEnumValues(RootKey: HKEY; Name: String; var ValueList: String): boolean;
begin
 Result := RegEnum(RootKey, Name, ValueList, False);
end;
function RegEnumKeys(RootKey: HKEY; Name: String; var KeyList: String): boolean;
begin
 Result := RegEnum(RootKey, Name, KeyList, True);
end;
end.