Pascal (Lazarus/Delphi)

Read the Target of a Symbolic Link

Demonstrates the Chilkat SFtp.ReadLink method, which returns the target path stored in a remote symbolic link. The only argument is the link path. The example then resolves the target to an absolute path with RealPath.

Background: ReadLink returns the raw string stored in the link exactly as it was created — which may be relative, absolute, or even dangling — without resolving it. That distinction matters: to learn where a link actually leads you follow it with RealPath, which canonicalizes the path on the server. Reading the raw target is the right choice when you need to inspect or preserve the link itself rather than its destination.

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Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.SFtp;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  sftp: TSFtp;
  port: Integer;
  password: string;
  target: string;
  absTarget: string;

begin
  success := False;

  //  Demonstrates the SFtp.ReadLink method, which returns the target path stored in a remote
  //  symbolic link.  The only argument is the link path.

  sftp := TSFtp.Create;

  //  Connect, authenticate, and initialize the SFTP subsystem.
  port := 22;
  success := sftp.Connect('sftp.example.com',port);
  if (success = False) then
    begin
      WriteLn(sftp.LastErrorText);
      Exit;
    end;

  //  Normally you would not hard-code the password in source.  You should instead obtain it
  //  from an interactive prompt, environment variable, or a secrets vault.
  password := 'mySshPassword';

  success := sftp.AuthenticatePw('mySshLogin',password);
  if (success = False) then
    begin
      WriteLn(sftp.LastErrorText);
      Exit;
    end;

  success := sftp.InitializeSftp();
  if (success = False) then
    begin
      WriteLn(sftp.LastErrorText);
      Exit;
    end;

  //  Read the target of a symbolic link.  The returned value is the raw target string stored in
  //  the link; it is not canonicalized and can be relative or absolute.
  target := sftp.ReadLink('subdir/latest.log');
  if (sftp.LastMethodSuccess = False) then
    begin
      WriteLn(sftp.LastErrorText);
      Exit;
    end;
  WriteLn('The link points to: ' + target);

  //  To resolve it to an absolute path, pass it to RealPath.
  absTarget := sftp.RealPath(target,'');
  if (sftp.LastMethodSuccess = False) then
    begin
      WriteLn(sftp.LastErrorText);
      Exit;
    end;
  WriteLn('Absolute target: ' + absTarget);

  sftp.Disconnect();


  sftp.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.