pgrp.c

#include <stdio.h>
#include <windows.h>
#include <tlhelp32.h>
#include <psapi.h>

int
main(int argc, char* argv[]) {
  int pid = -1, ppid = 1;
  HANDLE h = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
  PROCESSENTRY32 pe = { 0 };
  pe.dwSize = sizeof(PROCESSENTRY32);
  pid = GetCurrentProcessId();
  if ( Process32First(h, &pe)) {
	do {
	  if (pe.th32ProcessID == pid) {
		ppid = pe.th32ParentProcessID;
		break;
	  }
	} while( Process32Next(h, &pe));
  }

  if (Process32First(h, &pe)) {
	do {
	  if (pe.th32ParentProcessID == ppid) {
		HANDLE hp = OpenProcess(PROCESS_ALL_ACCESS, 0, pe.th32ProcessID);
		if (hp)  {
		  char fname[MAX_PATH];
		  DWORD c;
		  fname[0] = 0;
		  c = GetModuleFileNameEx(hp, NULL, fname, sizeof(fname));
		  fname[c] = 0;
		  puts(fname);
		  CloseHandle(hp);
		}
	  }
	} while( Process32Next(h, &pe));
  }
  CloseHandle(h);
  return 0;
}