# [solved] problem to drive a command prompt via a NamedPipe

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I'm trying to drive a command prompt by sending instructions via a NamedPipe.
This way you can (should) be able to send commands to the command prompt and at the same time "view" the result in the same window.
This is not allowed if you run a command prompt with "opt_flag" parameters (redirected streams) because this will disable StdOut on the cmd itself.

This small (trivial) snippet works for the first command sent to the cmd, but further submissions will fail.

Maybe the problem is in how I use the run () command to start a new cmd with the StdIn redirect from the NamedPipe. It seems that the generated cmd will close automatically after the first reception of the command via NamedPipe.

suggestions on how to make it work are welcome
thanks

#include <NamedPipes.au3>
#include <WinAPI.au3>

; Creates an instance of a named pipe
Global $sPipeName = "\\.\pipe\pipename" Global$hPipe = _NamedPipes_CreateNamedPipe($sPipeName, 1, 1) MsgBox(0, "Debug", "Pipe created. Now open a CMD") ; run a cmd with only StdIn redirected (StdIn data incoming from a pipe) Global$hCMD = Run(@ComSpec & " /K cmd < " & $sPipeName & @CRLF, "c:\") ; ok? MsgBox(0, "Debug", "now Send a command to the cmd via a NamedPipe") _StdInPipeWrite("dir" & @CRLF) MsgBox(0, 'Debug', "further commands will fail" & @CRLF & "now send command 'dir c:\windows'")$sMessage = "Dir c:\windows" & @CRLF
_StdInPipeWrite($sMessage) MsgBox(0, 'Debug', "send another command (will also fail)" & @CRLF & "now send command 'echo Hello'") _StdInPipeWrite("echo Hello" & @CRLF) MsgBox(0, "Debug", "end of test") ProcessClose($hCMD)

Func _StdInPipeWrite($sMessage) ; =============================================================================================================================== ; This function writes a message to the pipe ; =============================================================================================================================== Local$iWritten, $iBuffer,$pBuffer, $tBuffer$iBuffer = StringLen($sMessage) + 1$tBuffer = DllStructCreate("char Text[" & $iBuffer & "]")$pBuffer = DllStructGetPtr($tBuffer) DllStructSetData($tBuffer, "Text", $sMessage) If Not _WinAPI_WriteFile( _$hPipe, _ ; ...... Handle to the file to be written
$pBuffer, _ ; .... Pointer to the buffer containing the data to be written$iBuffer, _ ; .... Number of bytes to be written to the file
$iWritten, _ ; ... The number of bytes written 0 _ ; ............ [optional] A$tagOVERLAPPED structure or a pointer to it
) Then
ConsoleWrite("WriteMsg: _WinAPI_WriteFile failed" & @CRLF & _WinAPI_GetLastErrorMessage())
Else
ConsoleWrite("WriteMsg: write OK" & @CRLF & _WinAPI_GetLastErrorMessage() & @CRLF)
EndIf
EndFunc   ;==>_StdInPipeWrite

Edited by Chimp

Chimp

small minds discuss people average minds discuss events great minds discuss ideas.... and use AutoIt....

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... it seems that at the end of each command sent to cmd, there is a request pending from the pipe asking for something to the 'caller'. (something like'do you need to send more data?') I have seen that sending an @CRLF as the first character of the next sending allows you to send further commands to cmd via NomedPipe. As if the @CRLF accepts the default answer which I suppose is "yes, I have more data to send, stay connected" (?) ... or something similar.
However, although this workaround works (see line 30 in listing), it is not clear to me what happens under the hood.
if anyone has a clearer idea than mine, i would be glad to know it.
Thanks for any suggestions

#include <NamedPipes.au3>
#include <WinAPI.au3>

; Creates an instance of a named pipe
Global $sPipeName = "\\.\pipe\pipename" Global$hPipe = _NamedPipes_CreateNamedPipe($sPipeName, 1, 2) Global$sPrefix = ''

MsgBox(0, "Debug", "Pipe created. Now open a CMD")

; run a cmd with only StdIn redirected (StdIn data incoming from a pipe)
Global $hCMD = Run(@ComSpec & " /K cmd /K < " &$sPipeName & @CRLF, "c:\") ; ok? (maybe a better way?)

_StdInPipeWrite("@echo off" & @CRLF)
MsgBox(0, "Debug", "Result: @error:" & @error & @TAB & "$hCMD:" &$hCMD & @CRLF & "now Send a command to the cmd via a NamedPipe")
_StdInPipeWrite("cls & @Echo. & Echo Hello from AutoIt & Echo ----------------- & @Echo." & @CRLF)

MsgBox(0, 'Debug', "further commands" & @CRLF & "now send command 'dir c:\windows'")
$sMessage = "Dir c:\windows" & @CRLF _StdInPipeWrite($sMessage)

MsgBox(0, 'Debug', "send another command)" & @CRLF & "now send command 'cls & HELP'")
_StdInPipeWrite("cls & HELP" & @CRLF)

MsgBox(0, "Debug", "end of test")
ProcessClose($hCMD) Func _StdInPipeWrite($sMessage)

$sMessage = @CRLF &$sMessage ; <----------- Workaround

; ===============================================================================================================================
; This function writes a message to the pipe
; ===============================================================================================================================
Local $iWritten,$iBuffer, $pBuffer,$tBuffer

$iBuffer = StringLen($sMessage) + 1
$tBuffer = DllStructCreate("char Text[" &$iBuffer & "]")
$pBuffer = DllStructGetPtr($tBuffer)
DllStructSetData($tBuffer, "Text",$sMessage)
If Not _WinAPI_WriteFile( _
$hPipe, _ ; ...... Handle to the file to be written$pBuffer, _ ; .... Pointer to the buffer containing the data to be written
$iBuffer, _ ; .... Number of bytes to be written to the file$iWritten, _ ; ... The number of bytes written
0 _ ; ............ [optional] A $tagOVERLAPPED structure or a pointer to it ) Then ConsoleWrite("WriteMsg: _WinAPI_WriteFile failed" & @CRLF & _WinAPI_GetLastErrorMessage()) Else ConsoleWrite("WriteMsg: write OK" & @CRLF & _WinAPI_GetLastErrorMessage() & @CRLF) EndIf EndFunc ;==>_StdInPipeWrite Chimp small minds discuss people average minds discuss events great minds discuss ideas.... and use AutoIt.... ##### Link to post ##### Share on other sites Hi, i was just playing with this, searching for the solution. Then i saw your workaround, and then it clicked ! If you change the$iBuffer = StringLen($sMessage) + 1 and remove the +1, it should work. (from your 1st post) Logical explanation: Looks like the cmd is waiting for data, but got nothing, because the string length was too short. Edited by Dan_555 Some of my script sourcecode ##### Link to post ##### Share on other sites Thanks @Dan_555 Your explanation clarifies! I was completely out of the way. my hypothesis was due to the fact that among the different requests, on the cmd appears a string that says "Ancora?" that is the Italian word for "More?" hence my (incorrect) thesis. (Sometimes things are simpler than it seems) Thanks a lot for your solution! 👍 Edited by Chimp Chimp small minds discuss people average minds discuss events great minds discuss ideas.... and use AutoIt.... ##### Link to post ##### Share on other sites ## Create an account or sign in to comment You need to be a member in order to leave a comment ## Create an account Sign up for a new account in our community. It's easy! Register a new account ## Sign in Already have an account? Sign in here. Sign In Now • ### Recently Browsing 0 members No registered users viewing this page. • ### Similar Content • Hi, I am using python to call the Autoit function. I found a interesting problem. env: win10 64bit python3.6.4 x86、 python3.8.6 x64 autoit v3.3.16.0 code: #filename: demo.py from ctypes import windll dll = windll.LoadLibrary(r"D:\it_tools\autoit\AutoIt3\AutoItX\AutoItX3_x64.dll") # or AutoItX3.dll dll.AU3_Send("#r", 0) Behaviour: (1) run with the "python.exe" it will not open the run dialog, but input a "r" in the cmd window. (2) run with xxxxxx.exe (renamed from python.exe, you can rename whatever you like) work success I dont know why it happened. I think it shoule be related to Python and Autoit. So I came here... Can someone give me some advices. Thanks a lot. (by the way, My English is not very well... I wish I have provided the enough information... If you need more details, please contact me ) • By zoel Hello people, I have a script which calls CMD and executes the netstat command, but when I run it through SCITE the GUI opens but I have no output, How can I run the command as administrator? Here is my script so far #include <AutoItConstants.au3> #include <GUIConstantsEx.au3> #include <GuiEdit.au3> #include <ScrollBarsConstants.au3> #include <WindowsConstants.au3> #RequireAdmin Local$aWndPos Local $hWnd = GUICreate("Form2", 900, 420, -1, -1, Default +$WS_MAXIMIZE) GUISetBkColor(0xE4E4E4) Local $idFilemenu = GUICtrlCreateMenu("&File") Local$idExititem = GUICtrlCreateMenuItem("Exit", $idFilemenu) Local$idInput = GUICtrlCreateEdit("", 210, 10, 660, 360) GUICtrlSetResizing(-1, $GUI_DOCKBORDERS) GUICtrlSetFont(-1, 10, 400, Default, "COURIER NEW") Local$idButton = GUICtrlCreateButton("NetStat", 10, 10, 190, 25) GUICtrlSetResizing(-1, BitOR($GUI_DOCKLEFT,$GUI_DOCKTOP, $GUI_DOCKWIDTH,$GUI_DOCKHEIGHT)) GUISetState(@SW_SHOW) While 1 $nMsg = GUIGetMsg() Switch$nMsg Case $GUI_EVENT_CLOSE Exit Case$idExititem Exit Case $idButton GUICtrlSetData($idInput, _CmdInfo() & @CRLF) _GUICtrlEdit_Scroll($idInput,$SB_SCROLLCARET) _GUICtrlEdit_Scroll($idInput,$SB_SCROLLCARET) EndSwitch WEnd Func _CmdInfo($_sCmdInfo = "netstat /b") Local$iPID = Run(@ComSpec & " /c " & $_sCmdInfo, "", @SW_HIDE, BitOR($STDERR_CHILD, $STDOUT_CHILD)) ; Wait until the process has closed using the PID returned by Run. ProcessWaitClose($iPID) ; Read the Stdout stream of the PID returned by Run. This can also be done in a while loop. Look at the example for StderrRead. Local $sOutput = StringReplace(StdoutRead($iPID), @CRLF & @CRLF, @CRLF) Local $sOutErr = StringReplace(StderrRead($iPID), @CRLF & @CRLF, @CRLF) Local $sReult =$sOutput <> "" ? $sOutput :$sOutErr Return $sReult EndFunc • Hi There ! I have a script here : ;Launch CMD Run("C:\Windows\System32\cmd.exe") sleep(2000)$cmdHandle = WinActivate("C:\Windows\System32\cmd.exe")
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pb.start();

• By Burgs
Greetings,
I would like to be able to write a script to send commands to the console for creation of Gstreamer pipelines.  I was thinking of something similar to this:
Local $iPID = Run("C:\Windows\System32\cmd", "", @SW_MAXIMIZE) ;THIS OPENS THE CONSOLE...!!! if$iPID == 0 Then ConsoleWrite(@CRLF & "I DID NOT OPEN CMD...error: " & @error & @CRLF) if $iPID <> 0 Then ConsoleWrite(@CRLF & "I OPENED CMD...!!!" & @CRLF)$hCmd = WinGetHandle("C:\WINDOWS\system32\cmd.exe") if $hCmd <> 0 Then WinActivate($hCmd) ;ensure command console is active... $sOutput = Send("cd C:\gstreamer\1.0\x86_64\bin" & @CRLF,$SEND_RAW) $sOutput = Send("gst-launch-1.0 videotestsrc ! autovideosink" & @CRLF,$SEND_RAW) Sleep(3000) ControlSend($hCmd, "", "", "exit" & @CR) EndIf ;$hCmd NOT "0"... I don't really know if this is the best way to open the console and send commands into it.  I'm also not sure about how to best catch any errors that may occur...likely this needs to be accomplished with the STDOUTREAD command however I've not had experience using it before and therefore would appreciate some advice that anybody may offer.
Basically I'm seeking guidance on how to best automate the opening of the console, sending lines of commands to be executed, and handling any potential errors in the execution of those commands...I thank you in advance.  Regards.
Hi all,
I have a csv file as below, I wand to find srno from csv and send corresponding ip and pass to commend cmd prompt.
Please guide me to create script .
srno,name,ip,pass
1,name1,ip1,pass1
2,name2,ip2,pass2

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