Decode the octets with hexadecimal values.

Decode the octets with hexadecimal values.

[Hongyi Zhao]

Hi here,

According to one of the comments here [1], I try to read the related
discussion here [2], but al.howardknight.net doesn't do any decoding
of the articles and I will see some non-human readable stuff, for
example:

the shell first will do the same and then tell the kernel by means=20
of the system service =E2=80=9Cdup2=E2=80=9D to copy the contents of the en=
try #1 to=20
the entry #2.=C2=A0 Now two entries in the process' file descriptor=20
table=C2=A0=E2=80=93 #1 and #2=C2=A0=E2=80=93 refer to the opened file =E2=
=80=9Coutput.txt=E2=80=9D.

So, I would like to know how to decode the octets with hexadecimal
values with the help of Emacs.

[1] https://groups.google.com/g/comp.unix.shell/c/xXqxHrIchqg
[2] http://al.howardknight.net/?ID=165151671300

Best,
Zhao
-- 
Assoc. Prof. Hongsheng Zhao <hongyi.zhao@gmail.com>
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
No. 473, Quannan West Street, Xindu District, Xingtai, Hebei province

Re: Decode the octets with hexadecimal values.

[Platon Pronko]

On 2023-05-20 14:55, Hongyi Zhao wrote:
> Hi here,
> 
> According to one of the comments here [1], I try to read the related
> discussion here [2], but al.howardknight.net doesn't do any decoding
> of the articles and I will see some non-human readable stuff, for
> example:
> 
> the shell first will do the same and then tell the kernel by means=20
> of the system service =E2=80=9Cdup2=E2=80=9D to copy the contents of the en=
> try #1 to=20
> the entry #2.=C2=A0 Now two entries in the process' file descriptor=20
> table=C2=A0=E2=80=93 #1 and #2=C2=A0=E2=80=93 refer to the opened file =E2=
> =80=9Coutput.txt=E2=80=9D.
> 
> So, I would like to know how to decode the octets with hexadecimal
> values with the help of Emacs.
> 
> [1] https://groups.google.com/g/comp.unix.shell/c/xXqxHrIchqg
> [2] http://al.howardknight.net/?ID=165151671300
> 
> Best,
> Zhao

Hi!

That looks like quoted-printable encoding. I don't know how to decode that in Emacs,
but here's an example of how you can do that in Python:

import codecs
s = """
the shell first will do the same and then tell the kernel by means=20
of the system service =E2=80=9Cdup2=E2=80=9D to copy the contents of the en=
try #1 to=20
the entry #2.=C2=A0 Now two entries in the process' file descriptor=20
table=C2=A0=E2=80=93 #1 and #2=C2=A0=E2=80=93 refer to the opened file =E2=
=80=9Coutput.txt=E2=80=9D.
"""
print(codecs.decode(s.encode("utf8"), "QUOTED-PRINTABLE").decode("utf8").strip())

-- 
Best regards,
Platon Pronko
PGP 2A62D77A7A2CB94E

Re: Decode the octets with hexadecimal values.

[Hongyi Zhao]

On Sat, May 20, 2023 at 3:04 PM Platon Pronko <platon7pronko@gmail.com> wrote:
>
> On 2023-05-20 14:55, Hongyi Zhao wrote:
> > Hi here,
> >
> > According to one of the comments here [1], I try to read the related
> > discussion here [2], but al.howardknight.net doesn't do any decoding
> > of the articles and I will see some non-human readable stuff, for
> > example:
> >
> > the shell first will do the same and then tell the kernel by means=20
> > of the system service =E2=80=9Cdup2=E2=80=9D to copy the contents of the en=
> > try #1 to=20
> > the entry #2.=C2=A0 Now two entries in the process' file descriptor=20
> > table=C2=A0=E2=80=93 #1 and #2=C2=A0=E2=80=93 refer to the opened file =E2=
> > =80=9Coutput.txt=E2=80=9D.
> >
> > So, I would like to know how to decode the octets with hexadecimal
> > values with the help of Emacs.
> >
> > [1] https://groups.google.com/g/comp.unix.shell/c/xXqxHrIchqg
> > [2] http://al.howardknight.net/?ID=165151671300
> >
> > Best,
> > Zhao
>
> Hi!
>
> That looks like quoted-printable encoding. I don't know how to decode that in Emacs,
> but here's an example of how you can do that in Python:
>
> import codecs
> s = """
> the shell first will do the same and then tell the kernel by means=20
> of the system service =E2=80=9Cdup2=E2=80=9D to copy the contents of the en=
> try #1 to=20
> the entry #2.=C2=A0 Now two entries in the process' file descriptor=20
> table=C2=A0=E2=80=93 #1 and #2=C2=A0=E2=80=93 refer to the opened file =E2=
> =80=9Coutput.txt=E2=80=9D.
> """
> print(codecs.decode(s.encode("utf8"), "QUOTED-PRINTABLE").decode("utf8").strip())

Yes. This works.

But Emacs is also extremely powerful, I expect someone here can give
an Emacs-based solution.

> --
> Best regards,
> Platon Pronko
> PGP 2A62D77A7A2CB94E

Regards,
Zhao

Re: Decode the octets with hexadecimal values.

[Eli Zaretskii]

> From: Hongyi Zhao <hongyi.zhao@gmail.com>
> Date: Sat, 20 May 2023 15:37:42 +0800
> Cc: help-gnu-emacs <help-gnu-emacs@gnu.org>
> 
> But Emacs is also extremely powerful, I expect someone here can give
> an Emacs-based solution.

We have quoted-printable-decode-region.

Re: Decode the octets with hexadecimal values.

[Hongyi Zhao]

[-- Attachment #1: Type: text/plain, Size: 451 bytes --]

On Sat, May 20, 2023 at 4:18 PM Eli Zaretskii <eliz@gnu.org> wrote:
>
> > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > Date: Sat, 20 May 2023 15:37:42 +0800
> > Cc: help-gnu-emacs <help-gnu-emacs@gnu.org>
> >
> > But Emacs is also extremely powerful, I expect someone here can give
> > an Emacs-based solution.
>
> We have quoted-printable-decode-region.

But the result will be the one shown in the attached screenshot.

Best,
Zhao

[-- Attachment #2: image.png --]
[-- Type: image/png, Size: 176078 bytes --]

Re: Decode the octets with hexadecimal values.

[Eli Zaretskii]

> From: Hongyi Zhao <hongyi.zhao@gmail.com>
> Date: Sat, 20 May 2023 16:51:19 +0800
> Cc: help-gnu-emacs@gnu.org
> 
> On Sat, May 20, 2023 at 4:18 PM Eli Zaretskii <eliz@gnu.org> wrote:
> >
> > > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > > Date: Sat, 20 May 2023 15:37:42 +0800
> > > Cc: help-gnu-emacs <help-gnu-emacs@gnu.org>
> > >
> > > But Emacs is also extremely powerful, I expect someone here can give
> > > an Emacs-based solution.
> >
> > We have quoted-printable-decode-region.
> 
> But the result will be the one shown in the attached screenshot.

By default, the result is a unibyte string, you need to decode it to
get readable text:

  (quoted-printable-decode-region FROM TO 'utf-8)

(Do you read the doc strings of the functions before you use them?  If
not, you should: that's what they are there for.)

Re: Decode the octets with hexadecimal values.

[Hongyi Zhao]

On Sat, May 20, 2023 at 5:45 PM Eli Zaretskii <eliz@gnu.org> wrote:
>
> > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > Date: Sat, 20 May 2023 16:51:19 +0800
> > Cc: help-gnu-emacs@gnu.org
> >
> > On Sat, May 20, 2023 at 4:18 PM Eli Zaretskii <eliz@gnu.org> wrote:
> > >
> > > > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > > > Date: Sat, 20 May 2023 15:37:42 +0800
> > > > Cc: help-gnu-emacs <help-gnu-emacs@gnu.org>
> > > >
> > > > But Emacs is also extremely powerful, I expect someone here can give
> > > > an Emacs-based solution.
> > >
> > > We have quoted-printable-decode-region.
> >
> > But the result will be the one shown in the attached screenshot.
>
> By default, the result is a unibyte string, you need to decode it to
> get readable text:
>
>   (quoted-printable-decode-region FROM TO 'utf-8)
>
> (Do you read the doc strings of the functions before you use them?  If
> not, you should: that's what they are there for.)

Thank you for your valuable hints. The following steps do the trick:

1. C-x RET c utf-8-unix RET
2. Select/mark/highlight the text in question, and then
M-x quoted-printable-decode-region RET

Best,
Zhao

Re: Decode the octets with hexadecimal values.

[Hongyi Zhao]

[-- Attachment #1: Type: text/plain, Size: 1518 bytes --]

On Sat, May 20, 2023 at 6:53 PM Hongyi Zhao <hongyi.zhao@gmail.com> wrote:
>
> On Sat, May 20, 2023 at 5:45 PM Eli Zaretskii <eliz@gnu.org> wrote:
> >
> > > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > > Date: Sat, 20 May 2023 16:51:19 +0800
> > > Cc: help-gnu-emacs@gnu.org
> > >
> > > On Sat, May 20, 2023 at 4:18 PM Eli Zaretskii <eliz@gnu.org> wrote:
> > > >
> > > > > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > > > > Date: Sat, 20 May 2023 15:37:42 +0800
> > > > > Cc: help-gnu-emacs <help-gnu-emacs@gnu.org>
> > > > >
> > > > > But Emacs is also extremely powerful, I expect someone here can give
> > > > > an Emacs-based solution.
> > > >
> > > > We have quoted-printable-decode-region.
> > >
> > > But the result will be the one shown in the attached screenshot.
> >
> > By default, the result is a unibyte string, you need to decode it to
> > get readable text:
> >
> >   (quoted-printable-decode-region FROM TO 'utf-8)
> >
> > (Do you read the doc strings of the functions before you use them?  If
> > not, you should: that's what they are there for.)
>
> Thank you for your valuable hints. The following steps do the trick:
>
> 1. C-x RET c utf-8-unix RET
> 2. Select/mark/highlight the text in question, and then
> M-x quoted-printable-decode-region RET

But by comparing the results of Python and Emacs, we can see that
there are three redundant underscores in the latter, as shown in the
attached screenshot. Any tips for this behavior?

> Best,
> Zhao

[-- Attachment #2: image.png --]
[-- Type: image/png, Size: 266292 bytes --]

Re: Decode the octets with hexadecimal values.

[Eli Zaretskii]

> From: Hongyi Zhao <hongyi.zhao@gmail.com>
> Date: Sat, 20 May 2023 19:01:29 +0800
> Cc: help-gnu-emacs@gnu.org
> 
> But by comparing the results of Python and Emacs, we can see that
> there are three redundant underscores in the latter, as shown in the
> attached screenshot. Any tips for this behavior?

It's not an underscore, it's the NBSP character, I think?

Re: Decode the octets with hexadecimal values.

[Hongyi Zhao]

On Sat, May 20, 2023 at 8:37 PM Eli Zaretskii <eliz@gnu.org> wrote:
>
> > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > Date: Sat, 20 May 2023 19:01:29 +0800
> > Cc: help-gnu-emacs@gnu.org
> >
> > But by comparing the results of Python and Emacs, we can see that
> > there are three redundant underscores in the latter, as shown in the
> > attached screenshot. Any tips for this behavior?
>
> It's not an underscore, it's the NBSP character, I think?

Yes, you're right, as shown below:

M-x describe-char RET

             position: 152 of 260 (58%), column: 13
            character:   (displayed as  ) (codepoint 160, #o240, #xa0)
              charset: unicode (Unicode (ISO10646))
code point in charset: 0xA0
               script: latin
               syntax:       which means: whitespace
             category: .:Base, b:Arabic, j:Japanese, l:Latin
             to input: type "C-x 8 RET a0" or "C-x 8 RET NO-BREAK SPACE"
          buffer code: #xC2 #xA0
            file code: #xC2 #xA0 (encoded by coding system utf-8-unix)
              display: by this font (glyph code):
    ftcrhb:-PfEd-DejaVuSansMono Nerd Font
Mono-regular-normal-normal-*-20-*-*-*-m-0-iso10646-1 (#x62)
       hardcoded face: nobreak-space

Character code properties: customize what to show
  name: NO-BREAK SPACE
  old-name: NON-BREAKING SPACE
  general-category: Zs (Separator, Space)
  decomposition: (noBreak 32) (noBreak ' ')

There are text properties here:
  fontified            nil
  wrap-prefix          " "


Best,
Zhao