From: Denton Liu <liu.denton@gmail.com>
To: dash@vger.kernel.org
Subject: [BUG] one-shot variables aren't propagated past functions
Date: Thu, 30 Apr 2020 06:00:01 -0400 [thread overview]
Message-ID: <20200430100001.GA30093@generichostname> (raw)
Hi all,
I believe that I've encountered a bug in dash 0.5.10.2. With the
following input
f () {
echo $var
}
var=test f
echo $var
I would expect the output to be
test
test
but the output is actually
test
<blank>
It seems like this violates the POSIX spec. Quoting Junio C Hamano[1]:
> Johannes Sixt <j.sixt@viscovery.net> writes:
>
> > Tarmigan Casebolt schrieb:
> >> REQUEST_METHOD="GET" some_shell_function
> >
> >> I can't tell from my reading of the POSIX spec whether my usage was
> >> wrong or if dash is wrong,
> >
> > According to POSIX, variables set as shown above for shell functions are
> > not exported and retain their value after the function returns.
>
> I actually looked for this yesterday, but didn't find a relevant
> definition. But "2.9.5 Function Definition Command" [*1*] seems to
> address the issue: "When a function is executed, it shall have the
> syntax-error and variable-assignment properties described for special
> built-in utilities...".
>
> And "2.14 Special Built-in Utilities" section [*2*] says "2. Variable
> assignments specified with special built-in utilities remain in effect
> after the built-in completes...". Taking both together, it seems that
> the assignment should be in effect after the function returns.
>
[...]
>
> [References]
>
> *1* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_05
> *2* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_14
It also seems like on bash 5.0.16, running with --posix produces the
expected output, although without --posix it produces the blank line.
Originally discussed here[2].
Thanks,
Denton
[1]: https://lore.kernel.org/git/7vljfzz0yd.fsf@alter.siamese.dyndns.org/
[2]: https://lore.kernel.org/git/20200430092220.GA25331@generichostname/
next reply other threads:[~2020-04-30 10:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 10:00 Denton Liu [this message]
2020-04-30 15:12 ` [BUG] one-shot variables aren't propagated past functions Michael Greenberg
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