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Re: [SG16] SG16 meeting summary for December 9th, 2020

From: Tom Honermann <tom_at_[hidden]>
Date: Wed, 6 Jan 2021 10:40:32 -0500
On 1/6/21 8:30 AM, Hubert Tong wrote:
> On Wed, Jan 6, 2021 at 12:23 AM Tom Honermann <tom_at_[hidden]
> <mailto:tom_at_[hidden]>> wrote:
>
> On 1/4/21 10:10 PM, Hubert Tong wrote:
>> On Tue, Dec 29, 2020 at 1:11 AM Tom Honermann via SG16
>> <sg16_at_[hidden] <mailto:sg16_at_[hidden]>> wrote:
>>
>> The summary for the SG16 meeting held December 9th, 2020 is
>> now available. For those that attended, please review and
>> suggest corrections:
>>
>> * https://github.com/sg16-unicode/sg16-meetings#december-9th-2020
>>
>> Hi Tom,
>>
>> Thanks for the notes.
>>
>> With respect to the following:
>>
>> Hubert stated that encompasing the console in a separate facility
>> would pose challenges.
>>
>> I raised at least one specific challenge:
>>
>> Hubert stated that encompasing the console in a separate facility
>> would pose challenges because it assumes the presence of a unique
>> "console" in the environment.
>
> Thank you! Fixed!
>
> Thanks.
>
> I also archived the notes for meetings in 2020. The link above is
> still active, but an extra level of indirection has been
> introduced. The direct link to the notes for this meeting is now
> https://github.com/sg16-unicode/sg16-meetings/blob/master/README-2020.md#december-9th-2020.
>
>>
>> With regards to:
>>
>> Hubert explained that z/OS supports two modes:
>>
>> ASCII: interfaces are provided that perform conversion from
>> an internal encoding when writing to a stream; this is commonly
>> used for simple encodings.
>> EBCDIC: this is a byte pass through mode.
>>
>> I'm quite sure I didn't say that EBCDIC is a byte pass through mode.
>>
>> My recollection is that I said something like:
>> On z/OS, an application could internally be in ASCII or EBCDIC
>> mode. Open file handles can be imbued with the property of being
>> ASCII or EBCDIC. The C-level I/O APIs can automatically translate
>> at least single-byte encodings.
>
> Thanks, it looks like I projected some of my own limited
> (mis)understanding there. I applied your update.
>
> My understanding had been that, when in ASCII mode, the standard C
> interfaces transcode to EBCDIC. But I had not thought through the
> ability to tag files with an encoding in the filesystem; those
> tags presumably apply equally to programs running in ASCII vs
> EBCDIC mode. When you refer to open file handles being imbued with
> an encoding, is this via filesystem tags? Or are there other
> system interfaces to do this (I don't see, for example, a mode
> option for fopen()).
>
> Tags are involved, but are not the only way. The system interface can
> be accessed using fcntl() using F_CONTROL_CVT and F_SETTAG.

Thanks, Hubert!

For anyone interested, documentation on those fcntl() arguments can be
found here
<https://www.ibm.com/support/knowledgecenter/SSLTBW_2.4.0/com.ibm.zos.v2r4.bpxb100/fct.htm>.

Tom.

> Tom.
>
>>
>> -- HT
>
>


Received on 2021-01-06 09:40:35