xsnprintf (buf + strlen (buf), BUF_SIZE - strlen (buf), ":X%x,",
aexpr->len);
pkt = buf + strlen (buf);
for (ndx = 0; ndx < aexpr->len; ++ndx)
pkt = pack_hex_byte (pkt, aexpr->buf[ndx]);
*pkt = '\0';
xsnprintf (buf + strlen (buf), BUF_SIZE - strlen (buf), ":X%x,",
aexpr->len);
pkt = buf + strlen (buf);
for (ndx = 0; ndx < aexpr->len; ++ndx)
pkt = pack_hex_byte (pkt, aexpr->buf[ndx]);
*pkt = '\0';