Hi,

I hope I can find the right language to make myself clear.

I have accidentally discovered that I can read a pdf file from the
command line just by using "less -r":

$ less -r file.pdf

works beautifully and even maintains some formatting.

My shell is bash and my X terminal is mate-terminal:
https://manpages.debian.org/bullseye/mate-terminal/mate-terminal.1.en.html

If I launch from the terminal:
$ mate-terminal --full-screen -x /usr/bin/less -r Downloads/08\ Karzoff.pdf

This will open a new fullscreen window, rendering the pdf as intended.
https://i.imgur.com/R2opBmj.png

If I launch Caja (GUI file manager), right-click on the pdf > "open
with other application" > "use a custom command > mate-terminal
--full-screen -x /usr/bin/less -r > Open

this will display garbage, that is the pdf source code:
https://i.imgur.com/eAynhee.png

Any clue?

--
Ottavio Caruso

On Thu, 20 Oct 2022 14:46:27 +0000, Ottavio Caruso wrote:

> Hi,
>
> I hope I can find the right language to make myself clear.
>
> I have accidentally discovered that I can read a pdf file from the
> command line just by using "less -r":
>
> $ less -r file.pdf
>
> works beautifully and even maintains some formatting.
>
> My shell is bash and my X terminal is mate-terminal:
> https://manpages.debian.org/bullseye/mate-terminal/mate-terminal.1.en.html
>
> If I launch from the terminal:
> $ mate-terminal --full-screen -x /usr/bin/less -r Downloads/08\ Karzoff.pdf
>
> This will open a new fullscreen window, rendering the pdf as intended.
> https://i.imgur.com/R2opBmj.png
>
> If I launch Caja (GUI file manager), right-click on the pdf > "open
> with other application" > "use a custom command > mate-terminal
> --full-screen -x /usr/bin/less -r > Open
>
> this will display garbage, that is the pdf source code:
> https://i.imgur.com/eAynhee.png
>
> Any clue?

Yes. Look to the behaviour of your mate-terminal, when launched from
the desktop vs launched from Caja. The behaviour you see when launched
from Caja is the expected behaviour (PDFs contain PDF language instructions,
binary PDF instruction data (sometimes), optional binary display data,
and optional display text. I would not expect less(1), when run in a
terminal, to properly format the optional display text of a PDF and
/not/ display (or attempt to display) any of the binary data or PDF
instructions.

The results you get when launching from Caja is what I expect to see
from an attempt to less(1) a PDF file.

FWIW, why aren't you using pdftotext(1), which expressly designed
to extract and format the display text of a PDF file?
--
Lew Pitcher
"In Skills, We Trust"

On 20/10/2022 15:25, Lew Pitcher wrote:
> I would not expect less(1), when run in a
> terminal, to properly format the optional display text of a PDF and
> /not/ display (or attempt to display) any of the binary data or PDF
> instructions.

But it does, as evidenced by the screenshot in my OP.

>
> The results you get when launching from Caja is what I expect to see
> from an attempt to less(1) a PDF file.

Again, see screenshot 1.

>
> FWIW, why aren't you using pdftotext(1), which expressly designed
> to extract and format the display text of a PDF file?

Because pdftotext is not very scriptable and doesn't work as smoothly as
"less -r", some control characters are still left over.

>Look to the behaviour of your mate-terminal, when launched from
the desktop vs launched from Caja.

I expect mate-terminal to behave the same way if launched from the
terminal or from a file manager.

My feeling is that the "-r" argument doesn't get processed if launched
from the file manager.

--
Ottavio Caruso

Ottavio Caruso <ottavio2006-usenet2012@yahoo.com> writes:
> I hope I can find the right language to make myself clear.
>
> I have accidentally discovered that I can read a pdf file from the
> command line just by using "less -r":
>
> $ less -r file.pdf
>
> works beautifully and even maintains some formatting.

That's certainly not my experience.

You probably have the $LESSOPEN environment variable set to invoke
something like pdftotext on the input before displaying it.

`man less` and search for "INPUT PREPROCESSOR".

> My shell is bash and my X terminal is mate-terminal:
> https://manpages.debian.org/bullseye/mate-terminal/mate-terminal.1.en.html
>
> If I launch from the terminal:
> $ mate-terminal --full-screen -x /usr/bin/less -r Downloads/08\ Karzoff.pdf
>
> This will open a new fullscreen window, rendering the pdf as intended.
> https://i.imgur.com/R2opBmj.png
>
> If I launch Caja (GUI file manager), right-click on the pdf > "open
> with other application" > "use a custom command > mate-terminal
> --full-screen -x /usr/bin/less -r > Open
>
> this will display garbage, that is the pdf source code:
> https://i.imgur.com/eAynhee.png
>
> Any clue?

You probably have $LESSOPEN set in your interactive shell but not in
your file manager. In your GUI command, try changing "/usr/bin/less -r"
to "env LESSOPEN=... /usr/bin/less -r".

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

On Thu, 20 Oct 2022 15:37:51 +0000, Ottavio Caruso wrote:

> On 20/10/2022 15:25, Lew Pitcher wrote:
>> I would not expect less(1), when run in a
>> terminal, to properly format the optional display text of a PDF and
>> /not/ display (or attempt to display) any of the binary data or PDF
>> instructions.
>
> But it does, as evidenced by the screenshot in my OP.
>
>>
>> The results you get when launching from Caja is what I expect to see
>> from an attempt to less(1) a PDF file.
>
> Again, see screenshot 1.

Try your less(1) command in xterm, and see what happens.
For me, I get a warning that "... may be a binary file. See it anyway?"
and then, if I answer Y, I get the contents of such a file, binary and
PDF instructions included. This in xterm, konsole, and xfce-term, on a
PDF file I know was derived from text, and which pdftotext(1) properly
displays as text.

So, as far as /your/ setup is concerned, your "Launch mate-terminal and less
from Caja" results agrees with my results run from three different
terminal programs, and your "Launch mate-terminal and less from the desktop"
does not.

ISTM that the difference you see is in how mate-terminal behaves when
launched from the Mate desktop versus how it behaves when launched by
Caja. And the Caja behaviour is the "correct" (as in expected) behaviour.

>>
>> FWIW, why aren't you using pdftotext(1), which expressly designed
>> to extract and format the display text of a PDF file?
>
> Because pdftotext is not very scriptable and doesn't work as smoothly as
> "less -r", some control characters are still left over.

Huh? I beg to differ.
But that's a separate conversation.

>
> >Look to the behaviour of your mate-terminal, when launched from
> the desktop vs launched from Caja.
>
> I expect mate-terminal to behave the same way if launched from the
> terminal or from a file manager.
>
> My feeling is that the "-r" argument doesn't get processed if launched
> from the file manager.

My feeling is that, if the -r argument isn't processed, you should see
garbage on the terminal, and if it /is/ processed, you should see
/different/ garbage on the terminal. Given that, your "launch from
desktop" behaves as if something is filtering the binary data out /before/
less(1) sees it.

HTH
--
Lew Pitcher
"In Skills, We Trust"

On Thu, 20 Oct 2022 08:52:32 -0700, Keith Thompson wrote:

> Ottavio Caruso <ottavio2006-usenet2012@yahoo.com> writes:
>> I hope I can find the right language to make myself clear.
>>
>> I have accidentally discovered that I can read a pdf file from the
>> command line just by using "less -r":
>>
>> $ less -r file.pdf
>>
>> works beautifully and even maintains some formatting.
>
> That's certainly not my experience.
>
> You probably have the $LESSOPEN environment variable set to invoke
> something like pdftotext on the input before displaying it.
>
> `man less` and search for "INPUT PREPROCESSOR".
>
>> My shell is bash and my X terminal is mate-terminal:
>> https://manpages.debian.org/bullseye/mate-terminal/mate-terminal.1.en.html
>>
>> If I launch from the terminal:
>> $ mate-terminal --full-screen -x /usr/bin/less -r Downloads/08\ Karzoff.pdf
>>
>> This will open a new fullscreen window, rendering the pdf as intended.
>> https://i.imgur.com/R2opBmj.png
>>
>> If I launch Caja (GUI file manager), right-click on the pdf > "open
>> with other application" > "use a custom command > mate-terminal
>> --full-screen -x /usr/bin/less -r > Open
>>
>> this will display garbage, that is the pdf source code:
>> https://i.imgur.com/eAynhee.png
>>
>> Any clue?
>
> You probably have $LESSOPEN set in your interactive shell but not in
> your file manager. In your GUI command, try changing "/usr/bin/less -r"
> to "env LESSOPEN=... /usr/bin/less -r".

I don't use less(1) often, and didn't know about the LESSOPEN envar.
But, it jibes with my conclusion (stated in a followup to the OP) that
something is being set differently between the Mate desktop and the Caja
launcher. Likely, the desktop sets LESSOPEN to a filter that excludes
the non-essentials of a PDF (like, say, pdftotext(1)) but the Caja
launcher does not.

That's my guess, anyway.
--
Lew Pitcher
"In Skills, We Trust"

On 20/10/2022 15:52, Keith Thompson wrote:
> Ottavio Caruso <ottavio2006-usenet2012@yahoo.com> writes:
>> I hope I can find the right language to make myself clear.
>>
>> I have accidentally discovered that I can read a pdf file from the
>> command line just by using "less -r":
>>
>> $ less -r file.pdf
>>
>> works beautifully and even maintains some formatting.
>
> That's certainly not my experience.
>
> You probably have the $LESSOPEN environment variable set to invoke
> something like pdftotext on the input before displaying it.
>
> `man less` and search for "INPUT PREPROCESSOR".

Thanks. We're getting closer.

In terminal:
$ echo $LESSOPEN
| /usr/bin/lesspipe %s

So, this is the command I gave from Caja:

env LESSOPEN="| /usr/bin/lesspipe %s" mate-terminal --full-screen -x
/usr/bin/less -r

Result:

LESSOPEN ignored: must contain exactly one %s

Then I tried (without the %s)

env LESSOPEN="| /usr/bin/lesspipe" mate-terminal --full-screen -x
/usr/bin/less -r

Same as above.

>
> You probably have $LESSOPEN set in your interactive shell but not in
> your file manager. In your GUI command, try changing "/usr/bin/less -r"
> to "env LESSOPEN=... /usr/bin/less -r".
>

--
Ottavio Caruso

On Thu, 20 Oct 2022 15:37:51 +0000, Ottavio Caruso wrote:
> On 20/10/2022 15:25, Lew Pitcher wrote:

>>
>> FWIW, why aren't you using pdftotext(1), which expressly designed
>> to extract and format the display text of a PDF file?
>
> Because pdftotext is not very scriptable and doesn't work as smoothly as
> "less -r", some control characters are still left over.

Hmmm, I use it in several scripts to parse data from bank and IRS pdfs. Example
pdftotext -layout $pdf_fn $TMPDIR/xx

On Thu, 20 Oct 2022 11:57:46 -0500, Bit Twister wrote:

> On Thu, 20 Oct 2022 15:37:51 +0000, Ottavio Caruso wrote:
>> On 20/10/2022 15:25, Lew Pitcher wrote:
>
>>>
>>> FWIW, why aren't you using pdftotext(1), which expressly designed
>>> to extract and format the display text of a PDF file?
>>
>> Because pdftotext is not very scriptable and doesn't work as smoothly as
>> "less -r", some control characters are still left over.
>
> Hmmm, I use it in several scripts to parse data from bank and IRS pdfs. Example
> pdftotext -layout $pdf_fn $TMPDIR/xx

And, in the context of the OP's problem as he currently sees it,
#!/bin/bash
# Usage: lesspdfpipe.sh <pdf_file_name>
if [ "$1" ]
then
TARGET=$(tempfile)
if pdftotext -layout "$1" "$TARGET"
then
cat "$TARGET"
fi
fi

Example use:
LESSOPEN='|lesspdfpipe.sh %s' mate-terminal \
--full-screen \
-x /usr/bin/less -r some_random.pdf

--
Lew Pitcher
"In Skills, We Trust"

On Thu, 20 Oct 2022 17:06:05 +0000, Lew Pitcher wrote:

> On Thu, 20 Oct 2022 11:57:46 -0500, Bit Twister wrote:
>
>> On Thu, 20 Oct 2022 15:37:51 +0000, Ottavio Caruso wrote:
>>> On 20/10/2022 15:25, Lew Pitcher wrote:
>>
>>>>
>>>> FWIW, why aren't you using pdftotext(1), which expressly designed
>>>> to extract and format the display text of a PDF file?
>>>
>>> Because pdftotext is not very scriptable and doesn't work as smoothly as
>>> "less -r", some control characters are still left over.
>>
>> Hmmm, I use it in several scripts to parse data from bank and IRS pdfs. Example
>> pdftotext -layout $pdf_fn $TMPDIR/xx
>
> And, in the context of the OP's problem as he currently sees it,
> #!/bin/bash
> # Usage: lesspdfpipe.sh <pdf_file_name>
> if [ "$1" ]
> then
> TARGET=$(tempfile)
> if pdftotext -layout "$1" "$TARGET"
> then
> cat "$TARGET"
> fi
> fi

Or, better yet

#!/bin/bash
# Usage: lesspdfpipe.sh <pdf_file_name>
if [ "$1" ]
then
pdftotext -layout "$1" -
fi

--
Lew Pitcher
"In Skills, We Trust"

On Thu, 20 Oct 2022 17:08:09 +0000, Lew Pitcher wrote:

> On Thu, 20 Oct 2022 17:06:05 +0000, Lew Pitcher wrote:
>
>> On Thu, 20 Oct 2022 11:57:46 -0500, Bit Twister wrote:
>>
>>> On Thu, 20 Oct 2022 15:37:51 +0000, Ottavio Caruso wrote:
>>>> On 20/10/2022 15:25, Lew Pitcher wrote:
>>>
>>>>>
>>>>> FWIW, why aren't you using pdftotext(1), which expressly designed
>>>>> to extract and format the display text of a PDF file?
>>>>
>>>> Because pdftotext is not very scriptable and doesn't work as smoothly as
>>>> "less -r", some control characters are still left over.
>>>
>>> Hmmm, I use it in several scripts to parse data from bank and IRS pdfs. Example
>>> pdftotext -layout $pdf_fn $TMPDIR/xx
>>
>> And, in the context of the OP's problem as he currently sees it,
>> #!/bin/bash
>> # Usage: lesspdfpipe.sh <pdf_file_name>
>> if [ "$1" ]
>> then
>> TARGET=$(tempfile)
>> if pdftotext -layout "$1" "$TARGET"
>> then
>> cat "$TARGET"
>> fi
>> fi
>
> Or, better yet
>
> #!/bin/bash
> # Usage: lesspdfpipe.sh <pdf_file_name>
> if [ "$1" ]
> then
> pdftotext -layout "$1" -
> fi

Or, minimally
LESSOPEN='pdftotext -layout %s -' \
mate-terminal \
--full-screen \
-x /usr/bin/less -r some_random.pdf

--
Lew Pitcher
"In Skills, We Trust"

On Thu, 20 Oct 2022 17:11:10 +0000, Lew Pitcher wrote:

> On Thu, 20 Oct 2022 17:08:09 +0000, Lew Pitcher wrote:
>
>> On Thu, 20 Oct 2022 17:06:05 +0000, Lew Pitcher wrote:
>>
>>> On Thu, 20 Oct 2022 11:57:46 -0500, Bit Twister wrote:
>>>
>>>> On Thu, 20 Oct 2022 15:37:51 +0000, Ottavio Caruso wrote:
>>>>> On 20/10/2022 15:25, Lew Pitcher wrote:
>>>>
>>>>>>
>>>>>> FWIW, why aren't you using pdftotext(1), which expressly designed
>>>>>> to extract and format the display text of a PDF file?
>>>>>
>>>>> Because pdftotext is not very scriptable and doesn't work as smoothly as
>>>>> "less -r", some control characters are still left over.
>>>>
>>>> Hmmm, I use it in several scripts to parse data from bank and IRS pdfs. Example
>>>> pdftotext -layout $pdf_fn $TMPDIR/xx
>>>
>>> And, in the context of the OP's problem as he currently sees it,
>>> #!/bin/bash
>>> # Usage: lesspdfpipe.sh <pdf_file_name>
>>> if [ "$1" ]
>>> then
>>> TARGET=$(tempfile)
>>> if pdftotext -layout "$1" "$TARGET"
>>> then
>>> cat "$TARGET"
>>> fi
>>> fi
>>
>> Or, better yet
>>
>> #!/bin/bash
>> # Usage: lesspdfpipe.sh <pdf_file_name>
>> if [ "$1" ]
>> then
>> pdftotext -layout "$1" -
>> fi

Damn. Where did the pipe go? I thought I typed it.

> Or, minimally
LESSOPEN='|pdftotext -layout %s -' \
mate-terminal \
--full-screen \
-x /usr/bin/less -r some_random.pdf

--
Lew Pitcher
"In Skills, We Trust"

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
> Ottavio Caruso <ottavio2006-usenet2012@yahoo.com> writes:
>> I hope I can find the right language to make myself clear.
>>
>> I have accidentally discovered that I can read a pdf file from the
>> command line just by using "less -r":
>>
>> $ less -r file.pdf
>>
>> works beautifully and even maintains some formatting.
>
> That's certainly not my experience.
>
> You probably have the $LESSOPEN environment variable set to invoke
> something like pdftotext on the input before displaying it.
>
> `man less` and search for "INPUT PREPROCESSOR".
>
>> My shell is bash and my X terminal is mate-terminal:
>> https://manpages.debian.org/bullseye/mate-terminal/mate-terminal.1.en.html
>>
>> If I launch from the terminal:
>> $ mate-terminal --full-screen -x /usr/bin/less -r Downloads/08\ Karzoff.pdf
>>
>> This will open a new fullscreen window, rendering the pdf as intended.
>> https://i.imgur.com/R2opBmj.png
>>
>> If I launch Caja (GUI file manager), right-click on the pdf > "open
>> with other application" > "use a custom command > mate-terminal
>> --full-screen -x /usr/bin/less -r > Open
>>
>> this will display garbage, that is the pdf source code:
>> https://i.imgur.com/eAynhee.png
>>
>> Any clue?
>
> You probably have $LESSOPEN set in your interactive shell but not in
> your file manager. In your GUI command, try changing "/usr/bin/less -r"
> to "env LESSOPEN=... /usr/bin/less -r".

Incidentally, I don't think the "-r" option is relevant here. That
option causes less to display raw control characters. The output of
pdftotext shouldn't contain any control characters.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

On Thu, 20 Oct 2022 16:10:40 -0000 (UTC)
Lew Pitcher <lew.pitcher@digitalfreehold.ca> wrote:
> I don't use less(1) often, and didn't know about the LESSOPEN envar.

Out of curiosity , do you read man pages using something other than
less or you don't use man pages often ?

On Fri, 21 Oct 2022 09:50:11 +0000, Spiros Bousbouras wrote:

> On Thu, 20 Oct 2022 16:10:40 -0000 (UTC)
> Lew Pitcher <lew.pitcher@digitalfreehold.ca> wrote:
>> I don't use less(1) often, and didn't know about the LESSOPEN envar.
>
> Out of curiosity , do you read man pages using something other than
> less or you don't use man pages often ?

Up until now, I hadn't even considered what sort of pager man(1) uses.
Thanks to your query, I now know that I /do/ use less(1) often, but
not directly.

Thanks for the hint :-)
--
Lew Pitcher
"In Skills, We Trust"

In comp.unix.shell, Spiros Bousbouras <spibou@gmail.com> wrote:
> Out of curiosity , do you read man pages using something other than
> less or you don't use man pages often ?

I used to be a big fan of pg, but the hassle of installing it now has me
using whatever default the system comes with.

https://en.m.wikipedia.org/wiki/Pg_(Unix)

Elijah
------
also used to sometimes read man pages with lpr

On 22.10.2022 00:31, Eli the Bearded wrote:
>
> I used to be a big fan of pg, but the hassle of installing it now has me
> using whatever default the system comes with.

What?! 8-/

I have it installed on my (sort of) "legacy" Linux that I mostly use;
I think it was already there (no extra actions necessary). But now,
after your post, I see that on another (newer) system it's not there.
Has it - as I interpret your post - been removed from the distros? -
Darn! - Why?

Janis