[RUST] Determine current windows shell

shell.rs

/// get the parent process info, translated from
// https://gist.github.com/mattn/253013/d47b90159cf8ffa4d92448614b748aa1d235ebe4
fn get_parent_process_info() -> Option<(DWORD, String)> {
    let mut pe32: PROCESSENTRY32 = unsafe { zeroed() };
    let pid = unsafe { GetCurrentProcessId() };
    let h_snapshot = unsafe { CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0) };
    let mut ppid = 0;

    if h_snapshot == INVALID_HANDLE_VALUE {
        return None;
    }

    pe32.dwSize = std::mem::size_of::<PROCESSENTRY32>() as u32;

    if unsafe { Process32First(h_snapshot, &mut pe32) } != 0 {
        loop {
            if pe32.th32ProcessID == pid {
                ppid = pe32.th32ParentProcessID;
                break;
            }
            if unsafe { Process32Next(h_snapshot, &mut pe32) } == 0 {
                break;
            }
        }
    }

    let mut parent_process_name = None;
    if ppid != 0 {
        parent_process_name = get_process_name(ppid);
    }

    unsafe { CloseHandle(h_snapshot) };

    if let Some(ppname) = parent_process_name {
        Some((ppid, ppname))
    } else {
        None
    }
}
fn get_process_name(pid: DWORD) -> Option<String> {
    let mut pe32: PROCESSENTRY32 = unsafe { zeroed() };
    let h_snapshot = unsafe { CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0) };

    if h_snapshot == INVALID_HANDLE_VALUE {
        return None;
    }

    pe32.dwSize = std::mem::size_of::<PROCESSENTRY32>() as u32;

    if unsafe { Process32First(h_snapshot, &mut pe32) } != 0 {
        loop {
            if pe32.th32ProcessID == pid {
                let process_name_cstr = unsafe { CStr::from_ptr(pe32.szExeFile.as_ptr()) };
                let process_name = process_name_cstr.to_string_lossy().into_owned();
                unsafe { CloseHandle(h_snapshot) };
                return Some(process_name);
            }
            if unsafe { Process32Next(h_snapshot, &mut pe32) } == 0 {
                break;
            }
        }
    }

    unsafe { CloseHandle(h_snapshot) };
    None
}