DOS in a textbox

[conquerdude]

How can I run a dos program and output what it does into a textbox control in my VB app instead of the console window. I've seen porgrams do this before and it would be great if one of you could tell me how.

[jdc2000]

I'm not sure that you can get the output directly to VB, but what you can do is re-direct the output to a text file, then read in that file. Something like this:

Shell "DIR C:\*.* > DIRTEXT.TXT", vbMinimizedNoFocus
txtTextBox1.Text = vbNullString
Open "DIRTEXT.TXT" For Input As #1
Do While Not EOF(1)
Line Input #1, strTemp1
txtTextBox1.Text = txtTextBox1.Text & strTemp1 & vbCrLf
Loop
Close #1

[markman]

there was a recent sumbistion to www.pscode.com/vb about that

[JoshT]

Usage: Text1.Text = RunCommand("ipconfig")

Option Explicit
Option Base 0
'Code written by JoshT.  Use at your own risk :)
 
Private Declare Function CreateProcess Lib "kernel32" Alias "CreateProcessA" _
   (ByVal lpApplicationName As String, _
    ByVal lpCommandLine As String, _
    lpProcessAttributes As SECURITY_ATTRIBUTES, _
    lpThreadAttributes As SECURITY_ATTRIBUTES, _
    ByVal bInheritHandles As Long, _
    ByVal dwCreationFlags As Long, _
    lpEnvironment As Any, _
    ByVal lpCurrentDirectory As String, _
    lpStartupInfo As STARTUPINFO, _
    lpProcessInformation As PROCESS_INFORMATION) As Long
 
Private Declare Function CloseHandle Lib "kernel32.dll" (ByVal hObject As Long) As Long
 
Private Declare Function ReadFile Lib "kernel32" (ByVal hFile As Long, _
    lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, _
    lpOverlapped As Long) As Long
 
Private Declare Function WaitForSingleObject Lib "kernel32" _
    (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
 
Private Declare Function CreatePipe Lib "kernel32" (phReadPipe As Long, _
    phWritePipe As Long, lpPipeAttributes As SECURITY_ATTRIBUTES, _
    ByVal nSize As Long) As Long
 
Private Type STARTUPINFO
        cb As Long
        lpReserved As String
        lpDesktop As String
        lpTitle As String
        dwX As Long
        dwY As Long
        dwXSize As Long
        dwYSize As Long
        dwXCountChars As Long
        dwYCountChars As Long
        dwFillAttribute As Long
        dwFlags As Long
        wShowWindow As Integer
        cbReserved2 As Integer
        lpReserved2 As Long
        hStdInput As Long
        hStdOutput As Long
        hStdError As Long
End Type
 
Private Type PROCESS_INFORMATION
        hProcess As Long
        hThread As Long
        dwProcessId As Long
        dwThreadId As Long
End Type
 
Private Type SECURITY_ATTRIBUTES
        nLength As Long
        lpSecurityDescriptor As Long
        bInheritHandle As Long
End Type
 
Private Const NORMAL_PRIORITY_CLASS As Long = &H20&
 
Private Const STARTF_USESTDHANDLES As Long = &H100&
Private Const STARTF_USESHOWWINDOW As Long = &H1&
Private Const SW_HIDE As Long = 0&
 
Private Const INFINITE As Long = &HFFFF&
 
Public Function RunCommand(CommandLine As String) As String
    Dim si As STARTUPINFO 'used to send info the CreateProcess
    Dim pi As PROCESS_INFORMATION 'used to receive info about the created process
    Dim retval As Long 'return value
    Dim hRead As Long 'the handle to the read end of the pipe
    Dim hWrite As Long 'the handle to the write end of the pipe
    Dim sBuffer(0 To 63) As Byte 'the buffer to store data as we read it from the pipe
    Dim lgSize As Long 'returned number of bytes read by readfile
    Dim sa As SECURITY_ATTRIBUTES
    Dim strResult As String 'returned results of the command line
    
    'set up security attributes structure
    With sa
        .nLength = Len(sa)
        .bInheritHandle = 1& 'inherit, needed for this to work
        .lpSecurityDescriptor = 0&
    End With
    
    'create our anonymous pipe an check for success
    '   note we use the default buffer size
    '   this could cause problems if the process tries to write more than this buffer size
    retval = CreatePipe(hRead, hWrite, sa, 0&)
    If retval = 0 Then
        Debug.Print "CreatePipe Failed"
        RunCommand = ""
        Exit Function
    End If
    
    'set up startup info
    With si
        .cb = Len(si)
        .dwFlags = STARTF_USESTDHANDLES Or STARTF_USESHOWWINDOW 'tell it to use (not ignore) the values below
        .wShowWindow = SW_HIDE
'        .hStdInput = GetStdHandle(STD_INPUT_HANDLE)
        .hStdOutput = hWrite 'pass the write end of the pipe as the processes standard output
'        .hStdError = GetStdHandle(STD_ERROR_HANDLE)
    End With
    
    'run the command line and check for success
    retval = CreateProcess(vbNullString, _
                            CommandLine & vbNullChar, _
                            sa, _
                            sa, _
                            1&, _
                            NORMAL_PRIORITY_CLASS, _
                            ByVal 0&, _
                            vbNullString, _
                            si, _
                            pi)
    If retval Then
        'wait until the command line finishes
        '   trouble if the app doesn't end, or waits for user input, etc
        WaitForSingleObject pi.hProcess, INFINITE
        
        'read from the pipe until there's no more (bytes actually read is less than what we told it to)
        Do While ReadFile(hRead, sBuffer(0), 64, lgSize, ByVal 0&)
            'convert byte array to string and append to our result
            strResult = strResult & StrConv(sBuffer(), vbUnicode)
            'TODO = what's in the tail end of the byte array when lgSize is less than 64???
            Erase sBuffer()
            If lgSize <> 64 Then Exit Do
        Loop
        
        'close the handles of the process
        CloseHandle pi.hProcess
        CloseHandle pi.hThread
    Else
        Debug.Print "CreateProcess Failed" & vbCrLf
    End If
    
    'close pipe handles
    CloseHandle hRead
    CloseHandle hWrite
    
    'return the command line output
    RunCommand = Replace(strResult, vbNullChar, "")
End Function

[Hack]

Kudos Kudos and Bravo to JoshT.

Thats some slick code dude!!!!!

Not only did I run it with ipconfig, but I also ran it with ping and it worked like a champ.

Your routine will make another fine addition to my code library, with said code properly documented with respect to author, of course.

[JoshT]

Yeah, no problem. Spread it to those who need it.

[plenderj]

Originally posted by JoshT
Yeah, no problem. Spread it to those who need it.

Wow.
Just... wow

[cbond]

Josh, Thank you. Very well written and save me untold hours tyring to map a network that had no documentation at all. Was able to resolve all computer names to IP addresses quickly and easily.

Thank you!

[magicmohith]

that code waits for the whole program to finish and then copies stuff. is there a way of catching the text from DOS shell while the program is running in DOS?

and also the above code doesnt work with Win 2000. The VB program just hangs. is there a difference in Win 2000?

thanks
mohith

[chicocouk]

The code does work in windows 2000, because that's where I'm using it. And by the by, it's great code, and impresses the hell out of me

[cbond]

I'm running in XP, it works great.

Double check your DOS program. When it completes, to it say "press any key to continue"? If it does they your VB app will way for you DOS app to end, which is waiting for you to press a key... but the window is probably hidden and you can't press a key... (found that one out the hard way).

[JoshT]

Originally posted by cbond
I'm running in XP, it works great.

Double check your DOS program. When it completes, to it say "press any key to continue"? If it does they your VB app will way for you DOS app to end, which is waiting for you to press a key... but the window is probably hidden and you can't press a key... (found that one out the hard way).

I want to explain my code better, as it doesn't work the way people seem to think.

I wrote the code on a Windows 2000 box. It does not actually have anything to do with DOS - people mistakenly think typing the name of a Win32 *.exe is some kind of command when all Windows is doing is running the app with its standard IO stream set to the command prompt window (created by cmd.exe) - with my code, there is no hidden window, the console window was never created in the first place. Your VB app reads the spawned app's standard output with my code, rather than cmd.exe reading it and then writing it to the console window. So if the app does need user input, it is possible to write input to the spawned app's standard input stream (accessible via File API, like everything else).

[magicmohith]

i ran it in win 98 with same input and same program, it worked. but the same thing in Win 2000, just hangs. it doesnt crash, no error. the program doesnt respond at all. any difference?

it hangs when its calling the ReadFile API function. is it because win 2000 uses Overlapped type as the last argument for ReadFile rather than Long type?

For some reason, it doesnt work.

also is there a way to copy it real time for DOS rather than waiting for it to finish?

cheers
mohith

[JoshT]

Try running "ipconfig" or a different *.exe with it - certain apps might output text in different ways. ByVal 0& should be the same as passing NULL for the Overlapped structure.

To do it in real time - try call ReadFile before using WaitForSingleObject (or let the time less than INFINITE, etc).

[lightonr]

Attrib [path/filename] works great too!
Great code JoshT!

[CoderNewbie]

Looks good thanks for the cool code

[FrogBoy666]

When I run the exe, the first few lines are displayed in the textbox immediately, but as the SLOW exe churns away, the lines that appear after the first few aren't added to the textbox.

Is there any way to correct this?

[Fandy]

Very cool programming JoshT

[FrogBoy666]

Like I said, the code works great for the first few lines, then the console app pauses (with a blinking cursor), not waiting for user input, but just doing some calculations... this is where the above code stops reading the output.

I guess it could be very useful for other things, but not this one... unless anyone has any suggestions...