Detecting Computer Names on a Lan

[Turin]

Does anyone have a sample of how to detect all workstations currently logged into a LAN?

[Stevie-O]

Okay, to me a LAN is a group of computers that can talk to each other. Your question and the subject of the post are somewhat contradictive... do you want:

(a) To find out what computers are connected to a LAN?
(b) To find out what users are using said computers?
(c) To find out what users are logged into an NT domain?

[Turin]

Lets go with option A). To find out what computers are connected to a LAN?

[rchiav]

Do you want just Windows machines or UNIX machines also?

[Stevie-O]

All right! After wasting a good deal of time (which is okay, cuz it would have been wasted by something else otherwise), I did some research and got what you want.

You need to do some dirty VB stuff, though. If you're afraid of modifying raw object references, don't do anything.

If' you're NOT afraid, then go here:

http://www.mvps.org/btmtz/ishellex

And download the IShellEx example.

With some changes, it can be made to connect to Network Neighborhood and enumerate everything in there.

Heres the key piece of code I used for the sub main:

   Dim pidlNetHood As Long, pidlNetComputers As IEnumIDList
   Dim pFolder As Long
   Dim isfFolder As IShellFolder
   Dim IID_IShellFolder As GUID
   
   ' Fill IShellFolder Interface ID, {000214E6-0000-0000-C000-000000046}
   DEFINE_OLEGUID IID_IShellFolder, &H214E6, 0, 0
   
   ' Get the shell's allocator.
   If Not (SUCCEEDED(SHGetMalloc(pMalloc))) Then
     main1 = 1: Exit Function
   End If
   MoveMemory g_IMalloc, pMalloc, 4   ' Set g_IMalloc = pMalloc
  
   ' Get the PIDL for the Network Neighborhood folder.
   If Not (SUCCEEDED(SHGetSpecialFolderLocation(0, CSIDL_NETWORK, pidlNetHood))) Then
      Exit Function
   End If
   
   ' get an instance of IShellFolder
   Call SHGetDesktopFolder(pFolder)
   MoveMemory isfFolder, pFolder, 4&
 
   ' Bind to the folder
   Call isfFolder.BindToObject(pidlNetHood, 0, IID_IShellFolder, pFolder)
   Set isfFolder = Nothing ' remove our current instance
   MoveMemory isfFolder, pFolder, 4&
   Call isfFolder.EnumObjects(0&, SHCONTF_FOLDERS Or SHCONTF_NONFOLDERS Or SHCONTF_INCLUDEHIDDEN, pidlNetComputers)
     
   ' Process each item identifier in the list.
   Dim netHoodListPtr As Long, aSHITEMID As SHITEMID, pidl As Long
   netHoodListPtr = g_IMalloc.Alloc(LenB(aSHITEMID))
   pidlNetComputers.Next 1, netHoodListPtr, pidl
   Do While (pidl > 0)
     Dim sName As STRRET
     Dim pSubFolder As Long
     Dim pidlCopy As Long, curItem As ITEMIDLIST
     ' nethoodlistptr POINTS to an array of item ID lists
     MoveMemory curItem, ByVal netHoodListPtr, 4
     Call isfFolder.GetDisplayNameOf(netHoodListPtr, SHGDN_INFOLDER, sName)
     PrintStrRet netHoodListPtr, sName
     ' next!
     pidlNetComputers.Next 1, netHoodListPtr, pidl
   Loop
   ' free
   g_IMalloc.Free netHoodListPtr
   
   ' Release the shell's allocator.
   MoveMemory g_IMalloc, 0&, 4   ' Set g_IMalloc = Nothing, but without decreasing the refcount

You'll also need to go to http://www.vbaccelerator.com/ into the TLB section (it's under Resources in the contents) and download the ISHF_Ex.tlb file, and add it to the References section in VB.