vb cls_PipeAccess.cls

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 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 lpCurrentDriectory As String, _
lpStartupInfo As STARTUPINFO, lpProcessInformation As PROCESS_INFORMATION) As Long

Private Declare Function TerminateProcess _
Lib "kernel32" (ByVal hProcess As Long, _
ByVal uExitCode 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

Private Declare Function WriteFile _
Lib "kernel32" (ByVal hFile As Long, _
ByVal lpBuffer As String, _
ByVal nNumberOfBytesToWrite As Long, _
lpNumberOfBytesWritten As Long, _
lpOverlapped As Any) As Long

Private Declare Function GetFileSize _
Lib "kernel32" (ByVal hFile As Long, _
lpFileSizeHigh As Long) As Long

Private Declare Function CloseHandle _
Lib "kernel32" (ByVal hObject As Long) As Long

Private Declare Function GetLastError _
Lib "kernel32" () As Long

Private Declare Sub CopyMemory _
Lib "kernel32" _
Alias "RtlMoveMemory" (ByVal Destination As String, _
ByVal Source As String, _
ByVal Length As Long)

Private Declare Function lstrLen _
Lib "kernel32" _
Alias "lstrlenA" (ByVal lpString As String) 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 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 Const STARTF_USESTDHANDLES = &H100

Private Const STARTF_USESHOWWINDOW = &H1

Private Const NORMAL_PRIORITY_CLASS = &H20
Dim hReadPipe As Long
Dim hWritePipe As Long
Dim hReadFile As Long
Dim hWriteFile As Long
Dim pi As PROCESS_INFORMATION

Private Const Pipe_Max_Length As Long = 65536 '64K的空间

Public Function CreateProcessWithPipe(Optional ByVal FileName As String = "cmd.exe") As Boolean
On Error GoTo ErrHdl
Dim ret&
Dim sa As SECURITY_ATTRIBUTES

With sa
.nLength = Len(sa)
'.bInheritHandle = False
.bInheritHandle = True
.lpSecurityDescriptor = 0
End With

'create two pipe->one for input & output and another for err handle
ret = CreatePipe(hReadPipe, hWriteFile, sa, Pipe_Max_Length): If ret = 0 Then Call RaiseErr
ret = CreatePipe(hReadFile, hWritePipe, sa, Pipe_Max_Length): If ret = 0 Then Call RaiseErr
'since now , we had create two pipes.
Dim si As STARTUPINFO

'fill start info
With si
.cb = Len(si)
.hStdInput = hReadPipe
.hStdOutput = hWritePipe
.hStdError = hWritePipe
'in fact. both error msg and normal msg r msg, so we can let then in a same handle
.wShowWindow = 0 'hide it
.dwFlags = STARTF_USESTDHANDLES or STARTF_USESHOWWINDOW 'use handles, to make our hstd*** avable. use showwindow, to make our wShowWindow setting avable
End With

'createprocess----normally,it should be cmd.
ret = CreateProcess(vbNullString, FileName, sa, sa, True, NORMAL_PRIORITY_CLASS, 0&, App.Path, si, pi): If ret = 0 Then Call RaiseErr
CreateProcessWithPipe = True
Exit Function
ErrHdl:
Call TerminateProcessAndClosePipe
CreateProcessWithPipe = False
End Function

Public Function GetStringFromPipe() As String
On Error GoTo ErrHdl
Dim ret&
Dim sBuffer As String
Dim lRead As Long
Dim sReturn As String
sBuffer = Space$(Pipe_Max_Length)
ret = ReadFile(hReadFile, sBuffer, Len(sBuffer), lRead, ByVal 0&) 'lRead is bytes that had read actully
sReturn = Space$(lRead)
CopyMemory sReturn, sBuffer, lRead
GetStringFromPipe = sReturn
Exit Function
ErrHdl:
GetStringFromPipe = ""
End Function

Public Function PipeIsNull() As Boolean
PipeIsNull = (GetFileSize(hReadFile, 0&) <= 0)
End Function

Public Function PutStringToPipe(ByVal StrToPut As String) As Boolean
On Error GoTo ErrHdl
'most of time, u need to append a vbCrLf after the string u want to put.
Dim ret&
Dim lWrittenBytes As Long
ret = WriteFile(hWriteFile, StrToPut, lstrLen(StrToPut), lWrittenBytes, ByVal 0&): If ret = 0 Then Call RaiseErr
PutStringToPipe = (lWrittenBytes = Len(StrToPut))
Debug.Print hWriteFile
Exit Function
ErrHdl:
PutStringToPipe = False
End Function

Public Function TerminateProcessAndClosePipe() As Boolean
On Error GoTo ErrHdl
Dim ret&
ret = TerminateProcess(pi.hProcess, 0): If ret = 0 Then Call RaiseErr
ret = CloseHandle(hReadPipe): If ret = 0 Then Call RaiseErr
ret = CloseHandle(hReadFile): If ret = 0 Then Call RaiseErr
ret = CloseHandle(hWritePipe): If ret = 0 Then Call RaiseErr
ret = CloseHandle(hWriteFile): If ret = 0 Then Call RaiseErr
TerminateProcessAndClosePipe = True
Exit Function
ErrHdl:
TerminateProcessAndClosePipe = False
End Function

Private Sub RaiseErr()
On Error Resume Next
Err.Raise vbObjectError + 1 'raise an error so that to be caught by errhdl
End Sub