changes to ioctl has me flumoxed

[David Tilbrook]

To support my line editor I used to use:

        sgtty.c_lflag = ISIG;
        sgtty.c_iflag = BRKINT | IGNPAR | IXON | ICRNL;
        sgtty.c_oflag &= (ONLCR | OPOST | TAB3);
        sgtty.c_cc[VMIN] = 1;
        sgtty.c_cc[VTIME] = 1;
        iotcl(0, TCSETAW, &sgtty);

but this no longer appears to work in that input lines are repeated
and  the writes to reflect chanes are not done.

What should I be changing in the above, or what do I need to add?

-- david