Hacker News: pgtan

New comment by pgtan in "TIL: You can make HTTP requests without curl using Bash /dev/TCP"

pgtan — Tue, 16 Jun 2026 20:21:24 +0000

It is a KornShell feature since ca. 1997

https://github.com/ksh93/ast-open-archive/blame/master/src/c...

New comment by pgtan in "Do you even need a database?"

pgtan — Wed, 15 Apr 2026 15:57:39 +0000

Here are two checks using joins, one with sqlite, one with the join builtin of ksh93:

  check_empty_vhosts () {
    # Check which vhost adapter doesn't have any VTD mapped
    start_sqlite
    tosql "SELECT l.vios_name,l.vadapter_name FROM vios_vadapter AS l
        LEFT OUTER JOIN vios_wwn_disk_vadapter_vtd AS r
    USING (vadapter_name,vios_name)
    WHERE r.vadapter_name IS NULL AND
      r.vios_name IS NULL AND
   l.vadapter_name LIKE 'vhost%';"
    endsql
    getsql
    stop_sqlite
  }

  check_empty_vhosts_sh () {
    # same as above, but on the shell
    join  -v 1  -t , -1 1 -2 1 \
   <(while IFS=, read vio host slot; do 
  if [[ $host == vhost* ]]; then
      print ${vio}_$host,$slot 
  fi
     done < $VIO_ADAPTER_SLOT | sort -t , -k 1)\
   <(while IFS=, read vio vhost vtd disk; do
  if [[ $vhost == vhost* ]]; then        
    print ${vio}_$vhost
  fi
     done < $VIO_VHOST_VTD_DISK | sort -t , -k 1)
  }

New comment by pgtan in "Random Font – a typographic experiment exploring randomness [pdf]"

pgtan — Sat, 15 Nov 2025 10:21:34 +0000

Someone is reinventing PostScript and Metafont

https://www.moma.org/collection/works/139326

https://www.tug.org/TUGboat/tb09-2/tb21knut.pdf

New comment by pgtan in "Spotlight on pdfly, the Swiss Army knife for PDF files"

pgtan — Mon, 13 Oct 2025 20:28:19 +0000

Actually pdftex or luatex, but you are completely right, it can load a pdf file and do a lot of things with it.

The Illusion of Moral Superiority

pgtan — Sat, 13 Sep 2025 16:19:36 +0000

Article URL: https://pmc.ncbi.nlm.nih.gov/articles/PMC5641986/

Comments URL: https://news.ycombinator.com/item?id=45233272

Points: 4

# Comments: 0

New comment by pgtan in "EU to mobilize 200B Euros to invest in AI"

pgtan — Wed, 12 Feb 2025 12:29:00 +0000

socialism's new excuse to grab other people's money

New comment by pgtan in "Will better superconductors transform the world?"

pgtan — Sun, 19 May 2024 14:09:43 +0000

Does someone have stock portfolio of superconductor manufacturer to share? I watch Furukawa, Sumitomo, and AMSC and they are performing not bad.

New comment by pgtan in "Exploring Bauhaus: Revolutionary design school that shaped modern world"

pgtan — Mon, 11 Mar 2024 14:28:23 +0000

That article not even mention Bauhaus in Tel Aviv!

https://bauhaus-center.com/bauhaus-in-tel-aviv/

How Tech Giants Turned Ukraine Into an AI War Lab

pgtan — Wed, 14 Feb 2024 17:45:02 +0000

Article URL: https://time.com/6691662/ai-ukraine-war-palantir/

Comments URL: https://news.ycombinator.com/item?id=39372722

Points: 2

# Comments: 0

New comment by pgtan in "Intel QuickAssist Technology Zstandard Plugin for Zstandard"

pgtan — Thu, 17 Aug 2023 12:44:55 +0000

Well, POWER9 and later CPUs have builtin hardware compression using the 8-4-2 algorithm.

https://en.wikipedia.org/wiki/842_(compression_algorithm)

https://github.com/plauth/lib842

New comment by pgtan in "Simple Unix Chat"

pgtan — Thu, 06 Jul 2023 06:44:58 +0000

for builtin security see for example https://unix.stackexchange.com/questions/102746/how-to-invok...

New comment by pgtan in "Simple Unix Chat"

pgtan — Wed, 05 Jul 2023 15:41:02 +0000

OK, for starter the while loop. Main rule of writing shell scripts is, Use The Shell, Luke. Don't start external programs, if your shell (which is already running) can do it. "while /usr/bin/true" is nonsense, every time an external program gets executed for nothing. There are plenty of bash (since this shell is used in the example) internals, which evaluate to true, like ":", "test 1", "(( 1 ))", maybe others too. So "while :" should be better. But why even use dummy true statement, since the loop terminates with read? You can put the read as argument to while directly: "while read -r line; do" ... Same with echo and date. Just use one single printf builtin.

while read -r line ; do printf '%(%FT%T%z)T %-9s %s' -1 "$(/usr/bin/id --user --name --real)" "$line" ; done

New comment by pgtan in "Simple Unix Chat"

pgtan — Wed, 05 Jul 2023 10:51:05 +0000

This bash code is a parade example how NOT to write scripts.

New comment by pgtan in "The Case for Bash (2021)"

pgtan — Thu, 18 May 2023 11:48:19 +0000

Well, Kornshell (ksh93) has some nice programming features, much better than bash.

New comment by pgtan in "21y ex Ukrainian math olympiad team member killed by Russian shelling of Charkiv"

pgtan — Wed, 09 Mar 2022 07:24:16 +0000

Yuliya Zdanovska, here in an old team picture:

https://euromaidanpress.com/2017/04/13/ukrainian-schoolgirls...

21y ex Ukrainian math olympiad team member killed by Russian shelling of Charkiv

pgtan — Wed, 09 Mar 2022 07:22:53 +0000

Article URL: https://twitter.com/maxfargo88/status/1501444390140760071

Comments URL: https://news.ycombinator.com/item?id=30611809

Points: 20

# Comments: 3

New comment by pgtan in "X Window System on a Floppy"

pgtan — Mon, 13 Sep 2021 20:18:34 +0000

I for myself get annoyed every time I see this misspell. The name is X Window. Even microserfs can learn it.

New comment by pgtan in "IBM mainframe beats other platforms for cost and performance"

pgtan — Wed, 08 Sep 2021 17:33:44 +0000

[edit] sorry, I've mistaken the concepts. The name is active memory deduplication, which sits on top on memory sharing.

http://www.redbooks.ibm.com/redpapers/pdfs/redp4827.pdf

[old]

It is called active memory sharing in the POWER world

https://www.ibm.com/docs/en/power9/9080-M9S?topic=sharing-ma...

http://www.redbooks.ibm.com/redpapers/pdfs/redp4470.pdf

New comment by pgtan in "Rediscovering Logo with Bob the Turtle"

pgtan — Sun, 05 Sep 2021 07:33:36 +0000

This has nothing to do with Logo, the programming language. It's Python all the way down.

New comment by pgtan in "An Opinionated Guide to Xargs"

pgtan — Sun, 22 Aug 2021 08:33:00 +0000

Yes, you are right. Bash 5 on AIX 7.2 works with process substitution. Thanks for the advise!