I have an application that will work with the HOSTS file in the Windows\System32\drivers\etc folder. However, I don't want to hard code the path to C:\Windows\System32, because Windows might not be installed on drive C:.
I tried using %WinDir%\system32\drivers\etc\hosts, but this doesn't get expanded when it's used in the variable in my code.
How can I use %WinDir%\system32\drivers\etc\hosts as the path to the hosts file so I don't have to hard-code the path?
Another problem is that on successful compilation I have received one warning as
[DCC Warning] ApplicationWizard01.pas(67): W1002 Symbol 'TFileAttributes' is specific to a platform.
Code is shown in the answer here
Here is my new code :
unit KoushikHalder01;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons, Vcl.ExtCtrls,
Vcl.ComCtrls;
type
TForm01 = class(TForm)
Label01: TLabel;
Edit01: TEdit;
Edit02: TEdit;
BitBtn01: TBitBtn;
BitBtn02: TBitBtn;
procedure FormCreate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure FormShow(Sender: TObject);
procedure FormHide(Sender: TObject);
procedure BitBtn01MouseEnter(Sender: TObject);
procedure BitBtn02MouseEnter(Sender: TObject);
procedure BitBtn01MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure BitBtn02MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure BitBtn01MouseLeave(Sender: TObject);
procedure BitBtn02MouseLeave(Sender: TObject);
procedure BitBtn02Click(Sender: TObject);
procedure BitBtn01Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form01: TForm01;
implementation
{$R *.dfm}
uses System.IOUtils;
procedure TForm01.BitBtn01Click(Sender: TObject);
function GetSysDir: string;
function IncludeTrailingPathDelimiter(const S: string): string;
var
Attributes: TFileAttributes;
SL: TStringList;
Idx: Integer;
Buffer: array[0..MAX_PATH] of Char;
PathAndFileName : String;
begin
GetSystemDirectory(Buffer, MAX_PATH - 1);
SetLength(Result, StrLen(Buffer));
Result := Buffer;
PathAndFileName := CheckTrailingPathDelimiter(GetSysDir) + 'drivers\etc\hosts`;
Attributes := [];
TFile.SetAttributes('PathAndFileName', Attributes);
SL := TStringList.Create;
try
SL.LoadFromFile('PathAndFileName');
if
SL.IndexOf('10.220.70.34 VIRTSDP25') <> -1
then
begin
Edit02.Font.Color := clRed;
Edit02.Text := 'Your Host File Has Already Been Modified Successfully.';
end;
if
SL.IndexOf('10.220.70.34 VIRTSDP25') = -1
then
begin
SL.Add('10.220.70.34 VIRTSDP25');
Edit02.Font.Color := clGreen;
Edit02.Text := 'Your Host File Has Been Modified Successfully.';
end;
if
SL.IndexOf('10.220.70.32 BSNLESDP25A') = -1
then
SL.Add('10.220.70.32 BSNLESDP25A');
if
SL.IndexOf('10.220.70.33 BSNLESDP25B') = -1
then
SL.Add('10.220.70.33 BSNLESDP25B');
if
SL.IndexOf('10.220.70.34 VIRTBSNLESDP25') = -1
then
SL.Add('10.220.70.34 VIRTBSNLESDP25');
if
SL.IndexOf('10.220.70.34 KOSDPTwentyfive.bsnl.in.net') = -1
then
SL.Add('10.220.70.34 KOSDPTwentyfive.bsnl.in.net');
if
SL.IndexOf('10.220.70.34 KOSDPTwentyfive.bsnl.net.in') = -1
then
begin
SL.Add('10.220.70.34 KOSDPTwentyfive.bsnl.net.in');
SL.SaveToFile('PathAndFileName');
end;
finally
SL.Free;
end;
Include(Attributes, TFileAttribute.faSystem);
Include(Attributes, TFileAttribute.faReadOnly);
TFile.SetAttributes('PathAndFileName', Attributes);
end;
Don't use the %Windir%\System32. Use the Windows API's function designed specifically to find that folder, GetSystemDirectory. It's defined in the Windows unit; here's a quick wrapper (not tested on XE2, but works on XE):
Since you had problems with my previous answer, here's a fully-compiling copy of the code (I commented out your references to Edit02, so you'll need to uncomment them; everything else compiles just fine as is under XE2:
uses
System.IOUtils;
function GetSysDir: string;
var
Buffer: array[0..MAX_PATH] of Char;
begin
GetSystemDirectory(Buffer, MAX_PATH - 1);
SetLength(Result, StrLen(Buffer));
Result := Buffer;
end;
{$WARN SYMBOL_PLATFORM OFF}
procedure TForm2.Button1Click(Sender: TObject);
var
Attributes: TFileAttributes;
SL: TStringList;
Idx: Integer;
PathAndFileName : String;
begin
PathAndFileName := IncludeTrailingPathDelimiter(GetSysDir) + 'drivers\etc\hosts';
Attributes := [];
TFile.SetAttributes(PathAndFileName, Attributes);
SL := TStringList.Create;
try
SL.LoadFromFile(PathAndFileName);
if SL.IndexOf('10.220.70.34 VIRTSDP25') <> -1 then
begin
//Edit02.Font.Color := clRed;
//Edit02.Text := 'Your Host File Has Already Been Modified Successfully.';
end;
if SL.IndexOf('10.220.70.34 VIRTSDP25') = -1 then
begin
SL.Add('10.220.70.34 VIRTSDP25');
//Edit02.Font.Color := clGreen;
//Edit02.Text := 'Your Host File Has Been Modified Successfully.';
end;
if SL.IndexOf('10.220.70.32 BSNLESDP25A') = -1 then
SL.Add('10.220.70.32 BSNLESDP25A');
if SL.IndexOf('10.220.70.33 BSNLESDP25B') = -1 then
SL.Add('10.220.70.33 BSNLESDP25B');
if SL.IndexOf('10.220.70.34 VIRTBSNLESDP25') = -1 then
SL.Add('10.220.70.34 VIRTBSNLESDP25');
if SL.IndexOf('10.220.70.34 KOSDPTwentyfive.bsnl.in.net') = -1 then
SL.Add('10.220.70.34 KOSDPTwentyfive.bsnl.in.net');
if SL.IndexOf('10.220.70.34 KOSDPTwentyfive.bsnl.net.in') = -1 then
SL.Add('10.220.70.34 KOSDPTwentyfive.bsnl.net.in');
SL.SaveToFile(PathAndFileName);
finally
SL.Free;
end;
Include(Attributes, TFileAttribute.faSystem);
Include(Attributes, TFileAttribute.faReadOnly);
TFile.SetAttributes(PathAndFileName, Attributes);
end;
{$WARN SYMBOL_PLATFORM ON}