On 01/06/2015 08:29, Herbert Xu wrote:
On Fri, May 29, 2015 at 07:50:09AM +0200, Harald van Dijk wrote:
But the test script in this thread does invoke getopts with
parameters that are the same in all invocations, and without
modifying OPTIND. I don't see anything else in the normative
sections that would make the result undefined or unspecified either.
I do think the script is valid, and the results in dash should match
those of other shells.
The bash behaviour makes it impossible to call shell functions
that invoke getopts while in the middle of an getopts loop.
>
IMHO the dash behaviour makes a lot more sense since a function
always brings with it a new set of parameters. That plus the
fact that this behaviour has been there since day one makes me
reluctant to change it since the POSIX wording is not all that
clear.
True. Given that almost no shell supports that anyway, there can't be
too many scripts that rely on it, but I did warn about the risk of
breaking another type of existing scripts as well, I agree that's a real
concern.
One thing that doesn't really make sense, though: if the getopts
internal state is local to a function, then OPTIND and OPTARG really
should be too. Because they aren't, nested getopts loops already don't
really work in a useful way in dash, because the inner loop overwrites
the OPTIND and OPTARG variables. While OPTARG will typically be checked
right at the start of the loop, before any inner loop executes, OPTIND
is typically used at the end of the loop, in combination with the shift
command. The current behaviour makes the OPTIND value in that case
unreliable.
So either way, I think something should change. But if you prefer to get
clarification first about the intended meaning of the POSIX wording,
that certainly seems reasonable to me.
Cheers,
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