P_PGID
X(P_PID) X(P_PPID) X(P_PGID) X(P_SID) X(P_CID) X(P_UID) X(P_GID)
idtype = P_PGID;
idtype = P_PGID;
idtype = P_PGID;
case P_PGID:
idtype = P_PGID;
if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
idtype = P_PGID;
case P_PGID:
idtype = P_PGID;