I get an Error while communication vie ssh (plink.exe)
lazarus / 34-Windows

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kluesi · 2018-11-22 21:41

Hi

I use the following procedure to execute a process:

function GetDosOutput(CommandLine: string; Work: string = 'C:\'):
string;
var
  SA: TSecurityAttributes;
  SI: TStartupInfo;
  PI: TProcessInformation;
  StdOutPipeRead, StdOutPipeWrite: THandle;
  WasOK: Boolean;
  Buffer: array[0..255] of AnsiChar;
  BytesRead: Cardinal;
  WorkDir: string;
  Handle: Boolean;
begin
  Result := '';
  with SA do begin
    nLength := SizeOf(SA);
    bInheritHandle := True;
    lpSecurityDescriptor := nil;
  end;
  CreatePipe(StdOutPipeRead, StdOutPipeWrite, @SA, 0);
  try

    with SI do
    begin
      FillChar(SI, SizeOf(SI), 0);
      cb := SizeOf(SI);
      dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
      wShowWindow := SW_HIDE;
      hStdInput := GetStdHandle(STD_INPUT_HANDLE); // don't redirect
stdin
      hStdOutput := StdOutPipeWrite;
      hStdError := StdOutPipeWrite;
    end;
    WorkDir := Work;
    Handle := CreateProcess(nil, PChar('cmd.exe /C ' + CommandLine),
                            nil, nil, True, 0, nil,
                            PChar(WorkDir), SI, PI);
    CloseHandle(StdOutPipeWrite);
    if Handle then
      try
        repeat
          WasOK := ReadFile(StdOutPipeRead, Buffer, 255, BytesRead,
nil);
          if BytesRead > 0 then
          begin
            Buffer[BytesRead] := #0;
            Result := Result + Buffer;
          end;
        until not WasOK or (BytesRead = 0);
        WaitForSingleObject(PI.hProcess, INFINITE);
      finally
        CloseHandle(PI.hThread);
        CloseHandle(PI.hProcess);
      end;
  finally
    CloseHandle(StdOutPipeRead);
  end;
end;     
-----------------------------------------------------------
I tried this CommandLine:

plink.exe  -batch -ssh -2 -l XXXXXXX -pw YYYYYYYY -m
c:\Users\XXXXXX\command.sh SERVER

The file command.sh contains only one line:

echo "Hi" 1>&2;

I don't know exactly why I have to redirect the output, but it works.
I started the programm with Debugger and everything is ok. If I start
the xyz.exe I get the following Error Message:

Unable to read from standard input: Das Handle ist ungültig.

What do I wrong

Thank Kluesi

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Leledumbo · 2018-11-27 19:48

CreateProcess should return a BOOL (alias of LongBool), not a Boolean.
Boolean can only hold boolean with ordinal value of 0 and 1, while
BOOL can hold 32-bit unsigned integer (0 = false, anything else is
true). When assigned to the former, non-0 value will be converted into
1, I believe. Hence, you get invalid handle error.