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From: Ian Collins <ian-news@hotmail.com>
Newsgroups: comp.programming
Subject: Re: little-endian
Date: Sun, 18 Nov 2012 15:17:51 +1300
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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