How to close a process? about winsafe

[rodrigocfd]

I made a mistake, the result of CreateProcess is not a window handle.

Indeed, process and window are two completely different things. You cannot forcibly cast one handle into the other.

However, I am still curious about how to manually kill the process

I think you're after TerminateProcess.

[DaZiYuan]

I also want to know how to convert pi.hProcess to HWND. I would be grateful if you could help.

[rodrigocfd]

I want to close it programmatically

CreateProcess returns a CloseHandlePiGuard, which implements Drop to free the two handles returned in the struct: hProcess and hThread.

Any Drop in Rust can be prevented to run its destructor by passing the object to std::mem::forget. But then to free the handles manually you must keep them first, then rebuild the guards yourself:

use winsafe::{self as w, prelude::*, co};
	
let mut si = w::STARTUPINFO::default();
let pp = w::HPROCESS::CreateProcess(None, Some("notepad.exe"), None,
	None, false, co::CREATE::NoValue, None, None, &mut si).unwrap();

// get copies of the handles

let hprocess = unsafe { pp.hProcess.raw_copy() };
let hthread = unsafe { pp.hThread.raw_copy() };

// prevent the drop of the struct

std::mem::forget(pp);

// manually release the handles

unsafe {
	let _ = w::guard::CloseHandleGuard::new(hprocess);
	let _ = w::guard::CloseHandleGuard::new(hthread);
}

What you trying to do is called manual management of the handles, like we do in C. This is, of course, not recommended. It is always preferable to handle your object lifetime correctly, instead of bypass Rust's security features. Please don't do this.

I also want to know how to convert pi.hProcess to HWND.

All handles in WinSafe implement the Handle trait, which have a few basic operations, including raw pointer conversions:

let hwnd = unsafe { w::HWND::from_ptr( hprocess.as_ptr() ) };

I've never seen this conversion before: what's the situation where it's needed?

[DaZiYuan]

I tried this, but the notepad.exe didn't close successfully.

use winsafe::{self as w, prelude::*, co};
	
let mut si = w::STARTUPINFO::default();
let pp = w::HPROCESS::CreateProcess(None, Some("notepad.exe"), None,
	None, false, co::CREATE::NoValue, None, None, &mut si).unwrap();

// get copies of the handles

let hprocess = unsafe { pp.hProcess.raw_copy() };
let hthread = unsafe { pp.hThread.raw_copy() };

// prevent the drop of the struct

std::mem::forget(pp);

// manually release the handles

unsafe {
	let _ = w::guard::CloseHandleGuard::new(hprocess);
	let _ = w::guard::CloseHandleGuard::new(hthread);
}

I've never seen this conversion before: what's the situation where it's needed?

I want to create a new Notepad process and obtain its main handle. Then, I want to convert the handle to an HWND to use the SetParent() function.

[DaZiYuan]

I made a mistake, the result of CreateProcess is not a window handle. However, I am still curious about how to manually kill the process

[DaZiYuan]

It looks great, I hope to use it soon.

[DaZiYuan]

works well in 0.0.15