Re: Upcoming /bin/sh (mostly internal) change

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Fri, 17 Mar 2017 00:42:44 +0000 (UTC)
    From:        mlelstv%serpens.de@localhost (Michael van Elst)
    Message-ID:  <oafbe3$1bf$1%serpens.de@localhost>

  | That's two isatty() calls (== ioctl TIOCGETA) per arith expression.

Ah, that explains it.    Bizarre.   In sh $(( )) parsing, the entire
input is in an in-memory string, there are no files involved,
no fd's, and no I/O - and no rational reason at all for ever touching
any fd.

  | If I look at flex sources, it's difficult to avoid,

We will avoid it (in sh) by just not using lex (of any parentage) any more.
Problem gone.

Thanks,

kre