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From: Robert Elz <kre@munnari.OZ.AU>
Newsgroups: gnu.bash.bug
Subject: Re: Assignment-like word shouldn't be subjected to tilde expansion in POSIX mode
Date: Mon, 20 Jul 2020 15:28:33 +0700
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Xref: csiph.com gnu.bash.bug:16587

    Date:        Sun, 19 Jul 2020 15:21:07 -0400
    From:        Chet Ramey <chet.ramey=40case.edu>
    Message-ID:  <5f066ef0-1fed-ad5b-d564-490268d32427=40case.edu>

  =7C Maybe, but Posix says this isn't a variable assignment context, as =
POSIX
  =7C defines variable assignments, and technically  the shell shouldn't =
perform
  =7C tilde expansions after =60=3D' or =60:' at all. You could argue tha=
t bash has a
  =7C bug here in that it expands the tilde after the =60=3D'.

It may also be that this is a bug in POSIX, as all ksh shells seem to
act the way that bash does, expanding the first =7E but not the secpod.
Most other shells expand neither, except the NetBSD shell which treats
this as a var assignment (which it is really, however explained away in
POSIX) and expands both.

It is likely that if someone were to file a posix bug report about this,
it would turn into =22unspecified=22 whether =7E expansion is done in tha=
t context.

kre