forkptr
prf(forkptr(t)->forktre);
prio(forkptr(t)->forkio);
if (forkptr(t)->forktyp & FAMP)
freeio(forkptr(t)->forkio);
freetree(forkptr(t)->forktre);
execute(forkptr(t)->forktre, xflags | XEC_EXECED, errorflg);