List all critical processes on Windows

list_critical_processes.cpp

#include <windows.h>
#include <stdio.h>
#include <tchar.h>
#include <psapi.h>

void PrintProcessNameAndID(DWORD processID) {
	HANDLE hProcess = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE, processID);
	if (NULL != hProcess) {
		TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>");
		DWORD size = sizeof(szProcessName) / sizeof(TCHAR);
		QueryFullProcessImageName(hProcess, 0, szProcessName, &size);

		BOOL isProcessCritical = FALSE;
		if (IsProcessCritical(hProcess, &isProcessCritical) && isProcessCritical) {
			_tprintf(TEXT("%s  (PID: %u)\n"), szProcessName, processID);
		}
		CloseHandle(hProcess);
	}
}

int main() {
	DWORD aProcesses[1024], cbNeeded, cProcesses;
	if (!EnumProcesses(aProcesses, sizeof(aProcesses), &cbNeeded)) {
		return 1;
	}

	cProcesses = cbNeeded / sizeof(DWORD);
	for (unsigned int i = 0; i < cProcesses; i++) {
		if (aProcesses[i] != 0) {
			PrintProcessNameAndID(aProcesses[i]);
		}
	}

	return 0;
}