getpgid
if (getpgid(0) == getpid()) {
int getpgid(pid_t _pid);
pid_t getpgid(pid_t);
struct getpgid_args getpgid;
gkid = getpgid(kid);
child_pgrp = getpgid(child_pid);
child_pgrp = getpgid(child_pid);