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Re: little-endian

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On 11/18/12 11:22, BGB wrote:
> On 11/17/2012 2:48 PM, Robert Wessel wrote:
>> On Sun, 18 Nov 2012 09:28:16 +1300, Ian Collins<ian-news@hotmail.com>
>> wrote:
>>
>>> On 11/18/12 06:30, BGB wrote:
>>>>
>>>> typically, a person may develop and use functions like:
>>>> ReadInt32BE
>>>> and WriteInt64LE and similar, and use these for most of the encoding.
>>>
>>> Typically a programmer will use the utilities their platform provides.
>>>
>
> typically a programmer will do whatever is most convenient at the moment.

Which tends not to involve reinventing wheels!

<snip>

>>>> also, a big downside of using htonl and ntohl as a general mechanism is
>>>> that it makes all of ones' libraries need to depend on winsock.
>>>
>>> That's silly on at least three counts:
>>>
>>> 1) the whole would doesn't revolve around windows.
>>>
>>> 2) those utility functions are usually implemented in-line (typically as
>>> macros), so there isn't a library dependency.
>>>
>>> 3) if you are sending data over IP, you need the socket libraries one
>>> way or another!
>>
>
> you still have to include "winsock.h" or "sys/socket.h" (on Linux), and
> all the relevant #ifdef's, ..., or similar, which means that they don't
> really make sense except for code dealing with sockets.

The headers take care of the relevant defines.

> for most "general" file reader/writer code, it doesn't make sense to
> have such dependencies.

Unless you want to avoid wheel reinventing...

>> Some more valid criticisms of the hton*/ntoh* functions are that they
>> only support one byte order on the "network" side, support only a
>> couple of sizes, and only support unsigned values.

long long version are a simple extension.  The signed or unsigned nature 
of the type isn't relevant for byte ordering.

> and they only do direct value ->  value mappings...

Which is their purpose.

> far more common I think is to implement file-readers more like:
> int MyFile_ReadInt32LE(FILE *fd)

The reason for using the common byte ordering functions is to avoid 
having to care about the ordering on the wire (or in a file).

-- 
Ian Collins

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little-endian bob <bob@coolfone.comze.com> - 2012-11-15 13:45 -0800
  Re: little-endian JJ <jaejunks@glegooilma-swapit.com> - 2012-11-15 23:33 +0000
  Re: little-endian bob <bob@coolfone.comze.com> - 2012-11-16 10:38 -0800
    Re: little-endian "Pascal J. Bourguignon" <pjb@informatimago.com> - 2012-11-16 23:32 +0100
      Re: little-endian BGB <cr88192@hotmail.com> - 2012-11-16 21:17 -0600
        Re: little-endian "Pascal J. Bourguignon" <pjb@informatimago.com> - 2012-11-17 10:26 +0100
          Re: little-endian "BartC" <bc@freeuk.com> - 2012-11-17 11:38 +0000
            Re: little-endian "Pascal J. Bourguignon" <pjb@informatimago.com> - 2012-11-17 13:56 +0100
              Re: little-endian BGB <cr88192@hotmail.com> - 2012-11-17 11:58 -0600
            Re: little-endian Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-11-17 19:35 +0000
              Re: little-endian "BartC" <bc@freeuk.com> - 2012-11-17 19:50 +0000
          Re: little-endian BGB <cr88192@hotmail.com> - 2012-11-17 11:30 -0600
            Re: little-endian Ian Collins <ian-news@hotmail.com> - 2012-11-18 09:28 +1300
              Re: little-endian Robert Wessel <robertwessel2@yahoo.com> - 2012-11-17 14:48 -0600
                Re: little-endian BGB <cr88192@hotmail.com> - 2012-11-17 16:22 -0600
                Re: little-endian Ian Collins <ian-news@hotmail.com> - 2012-11-18 15:17 +1300
                Re: little-endian "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-11-18 09:13 +0100
                Re: little-endian Ian Collins <ian-news@hotmail.com> - 2012-11-18 21:33 +1300
                Re: little-endian "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-11-18 10:15 +0100
                Re: little-endian BGB <cr88192@hotmail.com> - 2012-11-18 03:03 -0600
                Re: little-endian "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-11-18 10:29 +0100
                Re: little-endian BGB <cr88192@hotmail.com> - 2012-11-18 12:50 -0600
  Re: little-endian Robin Vowels <robin.vowels@gmail.com> - 2012-11-22 04:49 -0800
    Re: little-endian Jongware <jongware@no-spam.plz> - 2012-11-23 15:22 +0100
      Re: little-endian pacman@kosh.dhis.org (Alan Curry) - 2012-11-25 19:39 +0000
        Re: little-endian Jongware <jongware@no-spam.plz> - 2012-11-26 12:01 +0100
          Re: little-endian "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-11-26 14:02 +0100
            Re: little-endian Jongware <jongware@no-spam.plz> - 2012-11-26 15:34 +0100
              Re: little-endian "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-11-26 17:03 +0100
              Re: little-endian Robert Wessel <robertwessel2@yahoo.com> - 2012-11-26 17:44 -0600
                Re: little-endian Robin Vowels <robin.vowels@gmail.com> - 2012-11-28 23:43 -0800
                Re: little-endian Robert Wessel <robertwessel2@yahoo.com> - 2012-11-29 22:46 -0600
          Re: little-endian BGB <cr88192@hotmail.com> - 2012-11-26 08:30 -0600
        Re: little-endian Robin Vowels <robin.vowels@gmail.com> - 2012-11-28 23:45 -0800

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