I have written some code that opens a new console application and attempts to read the standard output to a text box. However, when my ReadFile funtion tries to get data from the standard output when there is no data left to read, program crashes and I am not sure how to see if there is nothing left to read. Also, I want the console app to be invisible, and it doesn;t seem to close the console window when I close the handle. Any help would be appreciated. Thanks
Option Explicit
Private Declare Function CreatePipe Lib "kernel32" _
( _
phReadPipe As Long, _
phWritePipe As Long, _
lpPipeAttributes As Any, _
ByVal nSize As Long _
) _
As Long
Private Declare Function ReadFile Lib "kernel32" _
( _
ByVal hFile As Long, _
ByVal lpBuffer As String, _
ByVal nNumberOfBytesToRead As Long, _
lpNumberOfBytesRead As Long, _
ByVal lpOverlapped As Any _
) _
As Long
Private Declare Function CreateProcessA Lib "kernel32" _
( _
ByVal lpApplicationName As Long, _
ByVal lpCommandLine As String, _
lpProcessAttributes As Any, _
lpThreadAttributes As Any, _
ByVal bInheritHandles As Long, _
ByVal dwCreationFlags As Long, _
ByVal lpEnvironment As Long, _
ByVal lpCurrentDirectory As Long, _
lpStartupInfo As Any, _
lpProcessInformation 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 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 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
Const NORMAL_PRIORITY_CLASS = &H20&
Const STARTF_USESTDHANDLES = &H100&
Const STARTF_USESHOWWINDOW = &H1
Const SW_HIDE = 0&
Const SW_NORMAL = 1&
Public Sub ExecCmd(cmdline As String)
Dim proc As PROCESS_INFORMATION
Dim Result As Long
Dim bSuccess As Long
Dim start As STARTUPINFO
Dim sa As SECURITY_ATTRIBUTES
Dim hReadPipe As Long
Dim hWritePipe As Long
Dim Buffer As String
Dim L As Long
Dim A As Long
Dim dummy As Integer
sa.nLength = Len(sa)
sa.bInheritHandle = 1&
sa.lpSecurityDescriptor = 0&
Result = CreatePipe(hReadPipe, hWritePipe, sa, 0)
If Result = 0 Then
Err.Raise "Could not initialize the running of a console application."
Exit Sub
End If
start.cb = Len(start)
start.dwFlags = STARTF_USESTDHANDLES
start.hStdOutput = hWritePipe
start.wShowWindow = SW_HIDE
Result = CreateProcessA(0&, cmdline, sa, sa, 1&, NORMAL_PRIORITY_CLASS, 0&, 0&, start, proc)
If Result <> 1 Then
Err.Raise "Could not run GOLF program."
Else
Do
Buffer = String(2000, Chr(0))
bSuccess = ReadFile(hReadPipe, Buffer, Len(Buffer), L, 0&)
If bSuccess = 1 Then
frmMain.Text1.Text = frmMain.Text1.Text & Left(Buffer, L)
frmMain.Text1.SelStart = Len(frmMain.Text1.Text)
Else
Err.Raise "Could not interface with GOLF program."
End If
Loop
End If
Call CloseHandle(proc.hProcess)
Call CloseHandle(proc.hThread)
Call CloseHandle(hWritePipe)
Call CloseHandle(hReadPipe)
End Sub
