c++ - How to handle "End Task" from Windows Task Manager on a background process?

Question

I wrote a simple test program (TestProgram.exe) to learn how to handle the CTRL_CLOSE_EVENT and here are my observations and my question:

1) When I double click TestProgram.exe to launch it, and if I now go to Task Manager, TestProgram.exe is listed under "Apps". When I do "End Task" on TestProgram.exe, my handler for CTRL_CLOSE_EVENT is getting called.

BUT

2) When I open a command prompt and launch TestProgram.exe, it is listed under "Background Processes" under Task Manager and doing an "End Task" on the same doesn't result in a CTRL_CLOSE_EVENT.

My real application is used as described in case 2) above. I want to do some cleanup when users do an End Task on my app (which is listed under Background processes in Task Manager).

Thanks, Krishna

Answer 1

In general, when a process is listed as an "Application", it means Task Manger has detected the process has a GUI, and an "End Task" on a GUI will first attempt to graceful close the GUI via standard WM_CLOSE and/or WM_QUIT messages before then resorting to a brute-force termination of the GUI's process via TerminateProcess(). On the other hand, doing an "End Task" on a "Background Process" will perform a brute-force termination immediately.

So in your situation, double-clicking on the .exe file results in a new dedicated console process that is running just your app by itself, so the console's GUI gets flagged as an "Application", but when you open a console window first and execute your .exe via the command-line, your app is running within the existing console and is sharing the console's original GUI, so your app does not have its own GUI and thus gets flagged as a "Background Process" instead.