Re: IFS field splitting doesn't conform with POSIX

[Lawrence Velázquez]

On Thu, Mar 30, 2023, at 2:25 PM, Felipe Contreras wrote:
> On Thu, Mar 30, 2023 at 11:48 AM Oğuz İsmail Uysal
> <oguzismailuysal@gmail.com> wrote:
>>
>> On 3/30/23 7:51 PM, Felipe Contreras wrote:
>> > So? This is argumentum ad populum. The fact that most shells do X
>> > doesn't imply that POSIX says X.
>
>> POSIX documents existing practice.
>
> Your definition of what a standard is and mine are very different then.

The Austin Group itself largely disagrees with your position.


> In my view if POSIX was merely descriptive, then the Austin Group
> would have no need to discuss much, as it's fairly easy to describe
> what current shells do.

Composing technical specifications that describe implementations'
shared behaviors while allowing for their idiosyncrasies is more
involved than you seem to think.


> The challenge is in deciding what they *should* do, which is not
> descriptive, but prescriptive.

The Austin Group does not see its role as prescriptive, although
during discussions implementers are often open to modifying their
implementations to achieve consensus.  If many implementers agree
to make a change, the result may appear prescriptive.  (A recent
example is <https://austingroupbugs.net/view.php?id=1629>.)


>> If what it says differs from what the majority of shells do, then it's
>> POSIX that is wrong.
>
> Then there is no point in looking at the standard, since we know what
> it should say

The standard is a reference that describes a set of broadly common
behaviors.  Not everyone is interested in researching and testing
an assortment of implementations whenever they want to determine
whether a behavior is portable.

(Also: bash, dash, ksh, and zsh are not the only shells that exist.)


> and there's no point in discussing about what it does actually say.

You miss every shot you don't take.

https://www.opengroup.org/austin/lists.html


-- 
vq