I remember finding this bug but probably my modification didn't went through.

In the world of awk yes, but there's no way I would do that in C, and somehow doesn't make me want to do it in awk as well. If you're careful about speed you'll naturally not use that method despite appearing to be simpler. One could argue that that could be better but one would not.

Sometimes we think we could simplify things by minimizing our code but sometimes it just gets more bloated. Mine may not have been in its most optimized form but at least there's the balance. Yeah I know speed isn't crucial really but we have our opinions.

Edit: You could actually be correct about appending strings instead of calling multiple printfs since that could possibly cause multiple ioctl calls depending on awk's implementation, but I wouldn't consider print substr(s, length(OFS)+1).