CreateProcess的怪NSLOOKUP错误

Question

我有这样的API例程，我经常用来捕获DOS输出。最近，一个奇怪的错误已经发现似乎它并没有让DNS电话。例如NSLOOKUP将返回“没有响应从服务器”的错误与服务器：未知。如果你提供一个IP地址的ping会的工作，但是如果它有没有做一个DNS的呼叫。此问题是完全隔离，此代码。

任何深入了解这个问题，将不胜感激。 WINAPI是不是我的最强的区域。

编辑：对不起，将所有的常量和类型的，但我做了这个成为你可以粘贴到模块中，并努力使这个问题更容易解决运行测试自己

' STARTUPINFO flags
Private Const STARTF_USESHOWWINDOW = &H1
Private Const STARTF_USESTDHANDLES = &H100

' ShowWindow flag
Private Const SW_HIDE = 0

'CreatePipe buffer size
Private Const BUFSIZE = 1024

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

Private Declare Function CloseHandle Lib "kernel32.dll" (ByVal hObject As Long) As Long
Private Declare Function CreatePipe Lib "kernel32.dll" (ByRef phReadPipe As Long, ByRef phWritePipe As Long, ByRef lpPipeAttributes As SECURITY_ATTRIBUTES, ByVal nSize As Long) As Long
Private Declare Function CreateProcess Lib "kernel32.dll" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, ByRef lpProcessAttributes As SECURITY_ATTRIBUTES, ByRef lpThreadAttributes As SECURITY_ATTRIBUTES, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, ByRef lpEnvironment As Any, ByVal lpCurrentDriectory As String, ByRef lpStartupInfo As STARTUPINFO, ByRef lpProcessInformation As PROCESS_INFORMATION) As Long
Private Declare Sub GetStartupInfo Lib "kernel32.dll" Alias "GetStartupInfoA" (ByRef lpStartupInfo As STARTUPINFO)
Private Declare Function PeekNamedPipe Lib "kernel32.dll" (ByVal hNamedPipe As Long, ByRef lpBuffer As Any, ByVal nBufferSize As Long, ByRef lpBytesRead As Long, ByRef lpTotalBytesAvail As Long, ByRef lpBytesLeftThisMessage 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, lpOverlapped As Any) As Long

Sub CreateprocessApiTest()
    On Error GoTo errHandler
    Dim pa As SECURITY_ATTRIBUTES
    Dim pra As SECURITY_ATTRIBUTES
    Dim tra As SECURITY_ATTRIBUTES
    Dim si As STARTUPINFO
    Dim pi As PROCESS_INFORMATION
    Dim retVal As Long
    Dim command As String
    Dim ErrorDesc As String
    Dim hRead As Long     ' stdout + stderr
    Dim hWrite As Long
    Dim bAvail As Long    ' pipe bytes available (PeekNamedPipe)
    Dim bRead As Long     ' pipe bytes fetched   (ReadFile)
    Dim bString As String    ' our buffer
    Dim s As String

    command = "nslookup google.com"

    pa.nLength = Len(pa)
    pa.bInheritHandle = 1

    pra.nLength = Len(pra)
    tra.nLength = Len(tra)

    retVal = CreatePipe(hRead, hWrite, pa, BUFSIZE)

    With si
        .cb = Len(si)
        GetStartupInfo si
        .dwFlags = STARTF_USESHOWWINDOW Or STARTF_USESTDHANDLES
        .wShowWindow = SW_HIDE
        .hStdOutput = hWrite
        .hStdError = hWrite
    End With

    retVal = CreateProcess(vbNullString, command, pra, tra, 1, 0&, 0&, vbNullString, si, pi)

    Do While PeekNamedPipe(hRead, ByVal 0, 0, ByVal 0, bAvail, ByVal 0)
        DoEvents
        If bAvail Then
            bString = String(bAvail, 0)
            ReadFile hRead, bString, bAvail, bRead, ByVal 0&
            bString = Left(bString, bRead)
            s = s & bString
            CloseHandle hWrite
        End If
    Loop
    CloseHandle hRead
    CloseHandle pi.hThread
    CloseHandle pi.hProcess

    MsgBox s

exitRoutine:
    Exit Sub
errHandler:
    Debug.Print Err.Number, Err.Description
    Resume exitRoutine
End Sub

Answer 1

错误lpEnvironment As Any参数。添加ByVal这样

retVal = CreateProcess(vbNullString, command, pra, tra, 1, 0&, ByVal 0&, vbNullString, si, pi)