ConsIn / ConsOut under 9x

[Semen Matusovski]

It looks that these functions doesn't work correctly.
Does anybody know, how to detect redirection to pipes under 9x by normal way (maybe using int 21h or something else) ?



------------------

[Michael Mattias]

PB/CC 3.x:

IsRedirected = GETSTDOUT <> GetStdHandle (%STD_OUTPUT_HANDLE)

I qualified the PB/CC version because this is a known bug in PB/CC 3: GETSTDOUT does not return a handle to current STDOUT, it returns a handle to the console created by the program.

I have no clue if this behavior was corrected in CC4.

[later]
Oops, my bad. This is PB/DOS, not PB/CC.

Which begs the question...

How do you redirect the STDIN/STDOUT of an MS-DOS program to a pipe? About all I can think of is CreateProcess (commandshell) and redirect the STDOUT of (commandshell)?






[This message has been edited by Michael Mattias (edited April 25, 2005).]

[Semen Matusovski]

I call Pb-Dos 3.5 program from Pb/Win app.

Pb-Dos program works in two regims - 'normal' (if to run from Explorer) and 'secret' (if to run from Pb/Win).
My target is to hide 'secret' regime as possible.
Just now I used command line, what's I don't like.

------------------

[Michael Mattias]

You can't "call" a program.. I assume you mean you CreateProcess/ShellExecute/SHELL...

In which case, you could set an enviroment variable prior to launch.. the child process will be inherit the environement, and the environment variable will "die" when the calling process dies or when you reset it on return from the child process.

[Semen Matusovski]

Of course, CreateProcess.

   Function ShellHiddenConsoleApp (szExeDirectory As String, szExeName As String, szParam As String, szStartDirectory As String, _
      szStdInText As String, szStdOutText As String, ExitCode As Dword) As Dword

      Dim BytesRead                               As Local  Dword
      Dim BytesWritten                            As Local  Dword
      Dim dwResult                                As Local  Dword
      Dim fIsNt                                   As Local  Byte
      Dim hChildStdInRd                           As Local  Dword
      Dim hChildStdInWr                           As Local  Dword
      Dim hChildStdOutRd                          As Local  Dword
      Dim hChildStdOutWr                          As Local  Dword
      Dim os                                      As Local  OSVERSIONINFO
      Dim piProcInfo                              As Local  PROCESS_INFORMATION
      Dim saAttr                                  As Local  SECURITY_ATTRIBUTES
      Dim siStartInfo                             As Local  STARTUPINFO
      Dim szBuf                                   As Local  Asciiz * 4096
      Dim szPath                                  As Local  Asciiz * %MAX_PATH
      Dim szTmp                                   As Local  String

      szStdOutText = ""

      Do
         ' Set current directory and retrive short path for Exe (to avoid problems with CreateProcess in some OSes)
         szPath = szExeDirectory
         If szPath = "" Then GetCurrentDirectory SizeOf(szPath), szPath
         If Right$(szPath, 1) <> "\" Then szPath = szPath + "\"
         GetShortPathName szPath + szExeName, szPath, SizeOf(szPath)
         Replace " " With "" In szPath
         If szPath = "" Then dwResult = 1: Exit Do

         ' Set the bInheritHandle flag so pipe handles are inherited.
         saAttr.nLength = SizeOf(SECURITY_ATTRIBUTES)
         saAttr.bInheritHandle = 1

         ' Create a pipe For the child process's STDOUT.
         If CreatePipe (hChildStdOutRd, hChildStdOutWr, saAttr, ByVal 0) = 0 Then dwResult = 1: Exit Do
         ' Create a pipe For the child process's STDIN.
         If CreatePipe (hChildStdInRd,  hChildStdInWr,  saAttr, ByVal 0) = 0 Then dwResult = 1: Exit Do

         ' Write to StdIn
         If WriteFile (hChildStdInWr, ByVal StrPtr(szStdInText), Len(szStdInText), BytesWritten, ByVal 0) = 0 Then dwResult = 2: Exit Do
         If BytesWritten <> Len(szStdInText) Then dwResult = 2: Exit Do      

         '**** Start the program ****
         siStartInfo.cb = SizeOf(STARTUPINFO)
         siStartInfo.hStdError  = hChildStdOutWr
         siStartInfo.hStdOutput = hChildStdOutWr
         siStartInfo.hStdInput  = hChildStdInRd
         siStartInfo.wShowWindow  = %SW_HIDE
         siStartInfo.dwFlags = %STARTF_USESHOWWINDOW Or %STARTF_USESTDHANDLES

         os.dwOSVersionInfoSize = SizeOf(os)
         GetVersionEx ByVal VarPtr(os)
         If (os.dwPlatformId = %VER_PLATFORM_WIN32_NT) Then fIsNt = 1

         szTmp = szPath + " " + szParam
         If fIsNt Then szTmp = Environ$("COMSPEC") + " /c" + szTmp
         If CreateProcess ("", ByVal StrPtr(szTmp), ByVal 0&, ByVal 0&, 1, _
            %NORMAL_PRIORITY_CLASS, ByVal 0&, ByVal StrPtr(szStartDirectory), siStartInfo, piProcInfo) = 0 Then
            dwResult = 3: Exit Do
         Else
            WaitForSingleObject piProcInfo.hProcess, %INFINITE
            GetExitCodeProcess piProcInfo.hProcess, ExitCode
            CloseHandle piProcInfo.hThread
            CloseHandle piProcInfo.hProcess

            '**** Read the pipe ****
            Do
               szTmp = "End Of Pipe" ' Something unique
               If WriteFile (hChildStdOutWr, ByVal StrPtr(szTmp), Len(szTmp), BytesWritten, ByVal 0) = 0 Then dwResult = 2: Exit Do
               If BytesWritten <> Len(szTmp) Then dwResult = 2: Exit Do
               Do
                  If ReadFile (hChildStdOutRd, szBuf, SizeOf(szBuf), BytesRead, ByVal 0) = 0 Then dwResult = 2: Exit Do
                  If BytesRead = 0 Then Exit Do
                  szStdOutText = szStdOutText + Left$(szBuf, BytesRead)
                  If Right$(szStdOutText, Len(szTmp)) = szTmp Then _
                     szStdOutText = Left$(szStdOutText, Len(szStdOutText) - Len(szTmp)): Exit Do
               Loop
               If Len(szStdOutText) Then OemToCharBuff ByVal StrPtr(szStdOutText), ByVal StrPtr(szStdOutText), Len(szStdOutText)
               Exit Do
            Loop
         End If

         Exit Do
      Loop

      '*** Close pipe handles ****
      If hChildStdInRd  Then CloseHandle hChildStdInRd
      If hChildStdInWr  Then CloseHandle hChildStdInWr
      If hChildStdOutRd Then CloseHandle hChildStdOutRd
      If hChildStdOutWr Then CloseHandle hChildStdOutWr

      Function = dwResult

   End Function

I thought about environment and probably will use this way (better than command line).
But should be (I hope) direct way, using DOS functions.




[This message has been edited by Semen Matusovski (edited April 25, 2005).]

[Michael Mattias]

Might it make a difference if you were not writing to a pipe, versus writing to an 'ordinart' disk file?

Reason I ask is, the way you are doing this (waiting for the child process to finish before processing its output) there is no real advantage in using a pipe.

When the child process ends, you could just read the 'ordinary' disk file from start to end. (of course the pipe prohibits access by other processes and eliminates any problems you might encounter were that to occur)

I think there is an MS-DOS int &h21 service to obtain the (MS-DOS!) handles to stdout, stdin and stderr; but I can't see any function in PB/DOS which would allow you to open that file with a PB handle (like OPEN HANDLE under PB/WIN) and use PB file verbs, so I'm not sure that would get you a whole lot anyway.

You might be able to do something with the MS-DOS duplicate handle function.. I know I did 'something' with that about ten years ago.. I redirected the MS-DOS stdout from within a PB/DOS program to somewhere else...but that was a long time ago and memory is the second thing to go...

[Semen Matusovski]

ConsIn/ConsOut under 9x do not work with files also. Always - 1 instead of 0.
Sure, that should be possible to recognize redirection.
Probably, using IOCTL (2144). But I completely forgot all (last time I wrote low-level MS-DOS program in 1992).

Why I use pipes ?
This program tests license files, which linked with hardware.
I need info, which I can't get in 32-bit app.
Pipes are used for sequirity reasons.

Added later.
Probably I found the solution. Need to test in all OSes and to find explanation, why bit 5 of DX works, unlike expected bit 7.

 DefInt A-Z
 If ConsIn = 0 Then
    i = 1
 Else
    REG 1, &H4400
    REG 2, 0
    Call Interrupt &H21
    Dx?? = Reg(4)
    If (Dx?? And &H20) Then i = 1 Else i = 0
 End If


 If i Then StdOut "StdIn is redirected" Else StdOut "StdIn is not redirected"

 If ConsOut = 0 Then
    i = 1
 Else
    REG 1, &H4400
    REG 2, 1
    Call Interrupt &H21
    Dx?? = Reg(4)
    If (Dx?? And &H20) Then i = 1 Else i = 0
 End If
 If i Then StdOut "StdOut is redirected" Else StdOut "StdOut is not redirected"

 StdOut "ConsIn=" + Str$(ConsIn)
 StdOut "ConsOut=" + Str$(ConsOut)

[This message has been edited by Semen Matusovski (edited April 25, 2005).]