heredoc
void heredoc(Char *);
heredoc(t->t_dlef);
u = herein(iop->heredoc, iop->flag & IOEVAL);
iop->heredoc = NULL;
iop->heredoc = Xclose(xs, xp);
if ((iop->flag & IOTYPE) == IOHERE && iop->heredoc) {
shf_puts(iop->heredoc, shf);
if (p->heredoc != NULL)
q->heredoc = str_save(p->heredoc, ap);
afree(p->heredoc, ap);
char *heredoc;/* content of heredoc */