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From: =?utf-8?Q?Lawrence_Vel=C3=A1zquez?= <vq@larryv.me>
Newsgroups: gnu.bash.bug
Subject: Re: set -u not working as expected
Date: Sun, 2 Aug 2020 03:34:23 -0400
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> On Aug 2, 2020, at 2:51 AM, O=C4=9Fuz <oguzismailuysal@gmail.com> =
wrote:
>=20
> `u' has no members, so there's nothing to expand. If you use `${u[0]}' =
for
> example, you'll see an error, I think how bash and ksh behave is =
perfectly
> reasonable.

Agreed. Their behavior logically follows from POSIX's carveout for $@.

>> % bash -c 'set -u; typeset -i v; printf "<%s>\\n" "$v"'
>> bash: v: unbound variable
>> % ksh -c 'set -u; typeset -i v; printf "<%s>\\n" "$v"'
>> ksh: v: parameter not set
>> % zsh -c 'set -u; typeset -i v; printf "<%s>\\n" "$v"'
>> <0>
>>=20
>>=20
> `typeset -i v' doesn't assign `v', just gives it the integer =
attribute.
> Again, I can't see any problem with bash and ksh here.

Also agreed, but I was more interested in the next part...

>> % bash -c 'set -u; typeset -i v; v+=3D1; printf "<%s>\\n" "$v"'
>> <1>
>> % ksh -c 'set -u; typeset -i v; v+=3D1; printf "<%s>\\n" "$v"'
>> <1>
>> % zsh -c 'set -u; typeset -i v; v+=3D1; printf "<%s>\\n" "$v"'
>> <1>

...which contrasts with the behavior of let. Someone else will have
to explain this, as I don't know what to make of it.

vq=