Help me James

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  19 years ago

  by dhinakaran

  dhinakaran

  , United States

  Joined 19 years ago

  Form Vb Iam execute the Command.exe(with parameters) through SHELL.
  

  
  During execution if the Command.exe shows any error, then i want to show the error to the User.
  Here iam struggling how to catch the error in the Command.exe from VB and displayed to the User.
  

  
  So pls give idea how to do the above process.

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  19 years ago

  by James Crowley

  James Crowley

  London, United Kingdom

  Joined 20 years ago

  Why me??? ;-) I'm going on holiday in a few days... what will you do then ;-)
  

  
  Anyway, what you are trying to do is actually quite difficult! You need to capture the STDERR output. Below is some code I found on the web.
  

  
  

  
  

  
  This code is extremely useful if you ever need to capture output from a DOS screen/console. The simple demonstration below, shows how to capture the output from a batch file.
  

  
  Note, to redirect other handles (STDIN and STDERR), create a pipe for each handle for which redirection is desired. The code should read from the read ends of the pipes for the redirected STDOUT and STDERR. If STDIN redirection was desired, the could should write to the write end of the appropriate pipe.
  

  
  

  Code:

  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 GetNamedPipeInfo Lib "kernel32" (ByVal hNamedPipe As Long, lType As Long, lLenOutBuf As Long, lLenInBuf As Long, lMaxInstances 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
  

  
  Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) 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
  

  
  

  
  'Purpose     :  Synchronously runs a DOS command line and returns the captured screen output.
  'Inputs      :  sCommandLine                The DOS command line to run.
  '               [bShowWindow]               If True displays the DOS output window.
  'Outputs     :  Returns the screen output
  'Author      :  Andrew Baker
  'Date        :  03/09/2000 14:17
  'Notes       :  This routine will work only with those program that send their output to
  '               the standard output device (stdout).
  '               Windows NT ONLY.
  'Revisions   :
  

  
  Function ShellExecuteCapture(sCommandLine As String, Optional bShowWindow As Boolean = False) As String
     Const clReadBytes As Long = 256, INFINITE As Long = &HFFFFFFFF
     Const STARTFUSESHOWWINDOW = &H1, STARTFUSESTDHANDLES = &H100&
     Const SWHIDE = 0, SWNORMAL = 1
     Const NORMALPRIORITYCLASS = &H20&
     
     Const PIPECLIENTEND = &H0     'The handle refers to the client end of a named pipe instance. This is the default.
     Const PIPESERVEREND = &H1     'The handle refers to the server end of a named pipe instance. If this value is not specified, the handle refers to the client end of a named pipe instance.
     Const PIPETYPEBYTE = &H0      'The named pipe is a byte pipe. This is the default.
     Const PIPETYPEMESSAGE = &H4   'The named pipe is a message pipe. If this value is not specified, the pipe is a byte pipe
     
     
     Dim tProcInfo As PROCESSINFORMATION, lRetVal As Long, lSuccess As Long
     Dim tStartupInf As STARTUPINFO
     Dim tSecurAttrib As SECURITYATTRIBUTES, lhwndReadPipe As Long, lhwndWritePipe As Long
     Dim lBytesRead As Long, sBuffer As String
     Dim lPipeOutLen As Long, lPipeInLen As Long, lMaxInst As Long
     
     tSecurAttrib.nLength = Len(tSecurAttrib)
     tSecurAttrib.bInheritHandle = 1&
     tSecurAttrib.lpSecurityDescriptor = 0&
  

  
     lRetVal = CreatePipe(lhwndReadPipe, lhwndWritePipe, tSecurAttrib, 0)
     If lRetVal = 0 Then
         'CreatePipe failed
         Exit Function
     End If
  

  
     tStartupInf.cb = Len(tStartupInf)
     tStartupInf.dwFlags = STARTFUSESTDHANDLES Or STARTFUSESHOWWINDOW
     tStartupInf.hStdOutput = lhwndWritePipe
     If bShowWindow Then
         'Show the DOS window
         tStartupInf.wShowWindow = SWNORMAL
     Else
         'Hide the DOS window
         tStartupInf.wShowWindow = SWHIDE
     End If
  

  
     lRetVal = CreateProcessA(0&, sCommandLine, tSecurAttrib, tSecurAttrib, 1&, NORMALPRIORITYCLASS, 0&, 0&, tStartupInf, tProcInfo)
     If lRetVal <> 1 Then
         'CreateProcess failed
         Exit Function
     End If
     
     'Process created, wait for completion. Note, this will cause your application
     'to hang indefinately until this process completes.
     WaitForSingleObject tProcInfo.hProcess, INFINITE
     
     'Determine pipes contents
     lSuccess = GetNamedPipeInfo(lhwndReadPipe, PIPETYPEBYTE, lPipeOutLen, lPipeInLen, lMaxInst)
     If lSuccess Then
         'Got pipe info, create buffer
         sBuffer = String(lPipeOutLen, 0)
         'Read Output Pipe
         lSuccess = ReadFile(lhwndReadPipe, sBuffer, lPipeOutLen, lBytesRead, 0&)
         If lSuccess = 1 Then
             'Pipe read successfully
             ShellExecuteCapture = Left$(sBuffer, lBytesRead)
         End If
     End If
     
     'Close handles
     Call CloseHandle(tProcInfo.hProcess)
     Call CloseHandle(tProcInfo.hThread)
     Call CloseHandle(lhwndReadPipe)
     Call CloseHandle(lhwndWritePipe)
  End Function
  

  
  

  
  'Demonstration routine
  'NOTE: Create a file called "C:\test.bat" containing a single line:
  '   dir .
  Sub Test()
     Debug.Print ShellExecuteCapture("C:\test.bat", False)
  End Sub

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  19 years ago

  by dhinakaran

  dhinakaran

  , United States

  Joined 19 years ago

  Hai james
  

  
  Iam not getting the Output .pls help.
  

  
  thanks
  

  
  Dhinakaran

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