My Shares

I was back to my WIN32 programming days after a break. Reason being that I wanted to have an easy way of inserting a link to a local shared folder into the email message. For long I've been using a signature which contains only the NETBIOS machine name (these corporate machine names are long and difficult to remember) and would insert it and then complete the path by typing in the folder name. Wish I had a tray applet that would show the list of shared folders and allow me to copy the path to clipboard. Couldn't resist waiting more and after 2 hours of meddling around with MSDN help a tiny WTL app was up and running.
It was not very hard, but finding the right API's was a bit challenging. And then I was stuck at some conversion functions.
Here's are the main functions that I chose:
NetShareEnum - Gives the list of shared resources on a given machine
wcstombs - To convert wide str to mcbs (NetShareEnum returns wide str)
OpenClipboard, EmptyClipboard, SetClipboardData, CloseClipboard- For clipboard operations
GetAsyncKeyState - Status of shift key

Removing labels from VSS

If you had accidentally created a label for any items (file of directory), you can remove it by viewing the label from the item history, and deleting the label text. Close the dialog after confirmation and the label is removed. The changes would be affected globally irrespective of the item for which the label was modified.

Share data among processes through DLLs

I ran across this problem wherein I had to notify a process of an event which is triggered by another process through a DLL. Well, more precicely, the first process would invoke (this is an event) an exported function of the DLL and this function has to notify another process about this event. Now, this function could simply post a message to the main window of the second process, if it has a handle to it. Storing this handle is the problem. One obvious solution is to declare a static data in the dll and let the second process 'register' for notification by passing its window handle. Once it is stored, subsequent notifications are easy - just call PostMessage with this hwnd parameter. But there is a caveat. Eventhough DLL's map their code into the memory of each processes, it has separate instance for globals and static variables. Now these static members will be initialised separately for each processes when the DLL is loaded, which defeates the above method of sharing the window handle. There is a solution, atleast in MSVC environment. Create a named data-section in the dll code and place the data to be shared in it.

#pragma data_seg (".sharedseg")
HWND hNotifyWnd;
#pragma data_seg()

And give the linker option: /SECTION:.sharedseg,RWS

Logon Notification events under Windows

While working on the PSP program, I wanted to have a mechanism where to get notifications when the computer is locked and unlocked. Initially I thought that there would be some windows notification messages sent to every windows, but it was not the case. There is something called Windows Notification Package, which fecilitates the logon events for an application. All you need is to create a dll with required export functions (each function for Lock, Unlock, Logon,...) and create some registry entries. Now, this is a service of the Winlogon process, which is the main process started after the boot sequence. It is the Winlogon process that displays the SAS dialog. The registry key need to be created under:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify
Once the registry entries and dll are in place, the Windows need to be restarted. Apparently the Winlogon creates a list of notification functions at startup and debugging becomes a pain since the dll is locked by the process.