#if _WIN32_WINNT < 0x0500
# error "should be NT"
#endif
#include    <windows.h>
#include    <tlhelp32.h>
#include	<winternl.h>
#include    <stdio.h>

DWORD getppid()
{
    HANDLE hSnapshot = INVALID_HANDLE_VALUE;
    PROCESSENTRY32 pe32;
    DWORD ppid = 0, pid = GetCurrentProcessId();

    hSnapshot = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );
    __try{
        if( hSnapshot == INVALID_HANDLE_VALUE ) __leave;

        ZeroMemory( &pe32, sizeof( pe32 ) );
        pe32.dwSize = sizeof( pe32 );
        if( !Process32First( hSnapshot, &pe32 ) ) __leave;

        do{
            if( pe32.th32ProcessID == pid ){
                ppid = pe32.th32ParentProcessID;
                break;
            }
        }while( Process32Next( hSnapshot, &pe32 ) );

    }
    __finally{
        if( hSnapshot != INVALID_HANDLE_VALUE ) CloseHandle( hSnapshot );
    }
    return ppid;
}

DWORD getppid_nt() {
    NTSTATUS status;
    DWORD parent_pid = (DWORD)-1;
    HANDLE process;
    PROCESS_BASIC_INFORMATION pbi;
    ULONG retsize;
	typedef NTSTATUS (__stdcall *DefNtQueryInformationProcess)
		(HANDLE, PROCESSINFOCLASS, PVOID, ULONG, PULONG);
	DefNtQueryInformationProcess NtQueryInformationProcess;

    process = OpenProcess(
			PROCESS_QUERY_INFORMATION,
			FALSE,
			GetCurrentProcessId());
    if (!process)
        return (DWORD)-1;
	NtQueryInformationProcess = (DefNtQueryInformationProcess)
		GetProcAddress(GetModuleHandleA("ntdll"),
				"NtQueryInformationProcess");
	status = NtQueryInformationProcess(
			process,
			ProcessBasicInformation,
			(void*) &pbi,
			sizeof(PROCESS_BASIC_INFORMATION),
			&retsize
			);
	if (!status)
		parent_pid = (DWORD)pbi.Reserved3;
	CloseHandle(process);
    return parent_pid;
}

int main(){
    printf( "%lx\n", getppid() );
    printf( "%lx\n", getppid_nt() );

    return 0;

}