Command lines in VB

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Jul 21st, 2003, 12:17 PM
pinkclown

Command lines in VB

I'm trying to make a program that reads the dump file from an exe in the command prompt.

I have the exe that does what I want, but it's run in a command prompt. It can dump its output to a text file. So, I'm going to have it so the person enters a computer name (which goes into variable ComputerName), and when the program runs it will shell the command line which dumps to a text file, then the "front end" will import the data into a list box.

At a command prompt, you can type:

program.exe \\computername >c:\text.txt

and it'll dump the info to a text file. But if I do

Code:

Shell "C:\program.exe " & ComputerName & " >c:\text.txt", vbNormalFocus

it runs, but the exe says it can't find the process >c:\text.txt (info on specific processes is another thing it can do)

If I run just

Code:

Shell "C:\program.exe " & ComputerName

It works fine, of course it shows the data in the window, and doesn't dump into a text file that way ;)

So it looks like the problem is happening after the variable. I've tried using vbKeySpace instead of an actual space and some other silly stuff that didn't work. Anyone know what VB might be doing when it passes the command through, that would be making it see the command differently than plain old "program.exe \\computername >c:\text.txt"? :confused:
Jul 21st, 2003, 12:58 PM
phinds

could be that shell doesn't support pipes and an even less likely issue is that you might need a space after the pipe symbol
Jul 21st, 2003, 01:14 PM
pinkclown

Tried the space after the pipe, the program doesn't recognize the command then.. Ack, shell doesn't support pipes? :o If that's the case it would certainly explain it :(

Try this

VB Code:

Shell  chr(34) & "C:\program.exe " & ComputerName & " >c:\text.txt" & chr(34), vbNormalFocus

You could try the Shell API command...

VB Code:

Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Jul 23rd, 2003, 02:10 PM
pinkclown

thanks Woka, I tried that but now it doesn't launch at all. I changed ComputerName to include the blurb about dumping it to a text file so I could include it all as one command.

Code:

ComputerName = ComputerName & " >c:\text.txt" ShellExecute 0, vbNullString, "C:\program.exe", ComputerName, "C:\", SW_SHOWNORMAL

The cmd window doesn't even come up :(

I saw a post about assigning it to a long value to see if it's getting an error message when opening.
lngWhat returns 42. Have I found the meaning of the universe? At any rate I haven't found a way to get this darn thing to launch :o
Jul 23rd, 2003, 02:50 PM
jdc2000

Code:

Shell "C:\program.exe " & ComputerName & " > c:\text.txt", vbNormalFocus

Note the space after the ">"

Quote:

Originally posted by jdc2000

Code:

Shell "C:\program.exe " & ComputerName & " > c:\text.txt", vbNormalFocus

Note the space after the ">"

it should work regardless of space.

you could try this... redirects output of command window:

VB Code:

'Redirects output from console program to textbox.
'Requires two textboxes and one command button.
'Set MultiLine property of Text2 to true.
'
'Original bcx version of this program was made by
' dl <[email protected]>
'VB port was made by Jernej Simoncic <[email protected]>
'Visit Jernejs site at [url]http://www2.arnes.si/~sopjsimo/[/url]
'
'Note: don't run plain DOS programs with this example
'under Windows 95,98 and ME, as the program freezes when
'execution of program is finnished.
 
Option Explicit
Private Declare Function CreatePipe Lib "kernel32" (phReadPipe As Long, phWritePipe As Long, lpPipeAttributes As SECURITY_ATTRIBUTES, ByVal nSize As Long) As Long
Private Declare Sub GetStartupInfo Lib "kernel32" Alias "GetStartupInfoA" (lpStartupInfo As STARTUPINFO)
Private Declare Function CreateProcess Lib "kernel32" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, lpProcessAttributes As Any, lpThreadAttributes As Any, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, lpEnvironment As Any, ByVal lpCurrentDriectory As String, lpStartupInfo As STARTUPINFO, lpProcessInformation As PROCESS_INFORMATION) As Long
Private Declare Function SetWindowText Lib "user32" Alias "SetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String) As Long
Private Declare Function ReadFile Lib "kernel32" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, lpOverlapped As Any) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
 
Private Type SECURITY_ATTRIBUTES
  nLength As Long
  lpSecurityDescriptor As Long
  bInheritHandle As Long
End Type
 
Private Type PROCESS_INFORMATION
  hProcess As Long
  hThread As Long
  dwProcessId As Long
  dwThreadId As Long
End Type
 
Private Type STARTUPINFO
  cb As Long
  lpReserved As Long
  lpDesktop As Long
  lpTitle As Long
  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 Byte
  hStdInput As Long
  hStdOutput As Long
  hStdError As Long
End Type
 
Private Type OVERLAPPED
    ternal As Long
    ternalHigh As Long
    offset As Long
    OffsetHigh As Long
    hEvent As Long
End Type
 
Private Const STARTF_USESHOWWINDOW = &H1
Private Const STARTF_USESTDHANDLES = &H100
Private Const SW_HIDE = 0
Private Const EM_SETSEL = &HB1
Private Const EM_REPLACESEL = &HC2
 
Private Sub Command1_Click()
  Command1.Enabled = False
  Redirect Text1.Text, Text2
  Command1.Enabled = True
End Sub
Private Sub Form_Load()
    Text1.Text = "ping"
End Sub
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  If Command1.Enabled = False Then Cancel = True
End Sub
 
Sub Redirect(cmdLine As String, objTarget As Object)
  Dim i%, t$
  Dim pa As SECURITY_ATTRIBUTES
  Dim pra As SECURITY_ATTRIBUTES
  Dim tra As SECURITY_ATTRIBUTES
  Dim pi As PROCESS_INFORMATION
  Dim sui As STARTUPINFO
  Dim hRead As Long
  Dim hWrite As Long
  Dim bRead As Long
  Dim lpBuffer(1024) As Byte
  pa.nLength = Len(pa)
  pa.lpSecurityDescriptor = 0
  pa.bInheritHandle = True
  
  pra.nLength = Len(pra)
  tra.nLength = Len(tra)
 
  If CreatePipe(hRead, hWrite, pa, 0) <> 0 Then
    sui.cb = Len(sui)
    GetStartupInfo sui
    sui.hStdOutput = hWrite
    sui.hStdError = hWrite
    sui.dwFlags = STARTF_USESHOWWINDOW Or STARTF_USESTDHANDLES
    sui.wShowWindow = SW_HIDE
    If CreateProcess(vbNullString, cmdLine, pra, tra, True, 0, Null, vbNullString, sui, pi) <> 0 Then
      SetWindowText objTarget.hwnd, ""
      Do
        Erase lpBuffer()
        If ReadFile(hRead, lpBuffer(0), 1023, bRead, ByVal 0&) Then
          SendMessage objTarget.hwnd, EM_SETSEL, -1, 0
          SendMessage objTarget.hwnd, EM_REPLACESEL, False, lpBuffer(0)
          DoEvents
        Else
          CloseHandle pi.hThread
          CloseHandle pi.hProcess
          Exit Do
        End If
        CloseHandle hWrite
      Loop
      CloseHandle hRead
    End If
  End If
End Sub