[m-users.] Yet another piece for the posix library: strerror(3)

[Julien Fischer]

On Mon, 28 Oct 2019, Peter Wang wrote:

> On Mon, 28 Oct 2019 16:06:47 +1100 (AEDT), Julien Fischer <jfischer at opturion.com> wrote:
>>
>> Hi Volker
>>
>> On Sun, 27 Oct 2019, Volker Wysk wrote:
>>
>>> I've extended the posix library again, this time with the strerror(3)
>>> call. I had to modify posix.m in order to do it.
>>
>> That's not referentially transparent as the error message returned will
>> be affected by the current locale setting.  This can be fixed by making
>> the interface into:
>>
>>     :- pred strerror(posix.error::in, string::out, io::di, io::uo) is det.
>>
>
> The standard library makes the same mistake :P

Whether a locale change affects strerror() seems to be system dependent.
(It does on some systems, e.g. OpenBSD, which is sufficient reason to
fix the standard library.)

Julien.