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Writing bytes to stdout reverses the bytes


On Mon, Aug 20, 2018 at 12:01 PM, Grant Edwards
<grant.b.edwards at gmail.com> wrote:
> On 2018-08-20, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
>> Grant Edwards <grant.b.edwards at gmail.com> writes:
>>
>>> On 2018-08-20, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>>>> On Mon, 20 Aug 2018 00:31:35 +0000, Steven D'Aprano wrote:
>>>>
>>>>> When I write bytes to stdout, why are they reversed?
>>>>
>>>> Answer: they aren't, use hexdump -C.
>>>
>>> One might think that dumping out bytes in the correct order ought to
>>> be the default format for hexdump.
>>
>> It is if you run it as hd.
>
> What do you mean "run it as hd"?
>
> I don't see any mention of it the hexdump manpage, and I don't have an
> "hd" in my path.  Some commands alter their behavior based on argv[0],
> so I created an alias named "hd" that points to hexdump, but that
> doesn't do anything any different than "hexdump":
>
> $ which hexdump
> /usr/bin/hexdump
>
> $ ls -l $(which hd)
> lrwxrwxrwx 1 grante users 16 Aug 19 21:00 /home/grante/bin/hd -> /usr/bin/hexdump
>
> $ hd .bashrc | head -n2
> 0000000 2023 652f 6374 732f 656b 2f6c 622e 7361
> 0000010 7268 0a63 0a23 2023 6854 7369 6620 6c69
>
> $ hexdump .bashrc | head -n2
> 0000000 2023 652f 6374 732f 656b 2f6c 622e 7361
> 0000010 7268 0a63 0a23 2023 6854 7369 6620 6c69
>

Your system is different from mine, then.

rosuav at sikorsky:~$ ls -l $(which hd)
lrwxrwxrwx 1 root root 7 Apr 12  2017 /usr/bin/hd -> hexdump
rosuav at sikorsky:~$ ls -l $(which hexdump)
-rwxr-xr-x 1 root root 27248 Apr 12  2017 /usr/bin/hexdump

In 'man hexdump', the -C option says:
     -C      Canonical hex+ASCII display.  Display the input offset in hexa?
             decimal, followed by sixteen space-separated, two column, hexa?
             decimal bytes, followed by the same sixteen bytes in %_p format
             enclosed in ``|'' characters.

             Calling the command hd implies this option.

I'm on Debian GNU/Linux, and the 'hexdump' command comes from a
package called bsdmainutils. What are you on, and where is your
hexdump from?

ChrisA