How to Kill Zombie Processes on Linux

We can list zombie processes by using the ps command and piping its output into egrep command. Zombie processes have a state flag of "Z," and you'll usually also see "defunct."

 Type the following command on a terminal:

ps aux | egrep "Z|defunct"

The zombie process will be listed and you can also see the program that spawned these zombies.

Once we have the process ID of the first zombie, we need to find the process ID of its parent process. We can do so by using ps again. We'll use the output option (-o) to tell ps to display only the parent's process ID, and then pass it with the ppid= flag.

The process we want to find will be indicated by using the -p (process) option, and then passing in the zombie's process ID.

Therefore, we type the following command to look up the process information for process with ID = 7641, and it will only report the ID of the parent process:

ps -o ppid= -p 7641

The output of the command will be the ID of the parent process then you can use the kill command to terminate the parent process if that is safe to do and the zombie process will go away.

Taken from: https://www.howtogeek.com/701971/how-to-kill-zombie-processes-on-linux/

Calculating time diff between two date times in Perl

A short script for calculating difference between two date times in Perl.

See source code on GitHub: https://github.com/64board/Perl/blob/main/time_diff_time_piece.pl

The Perl Time::Piece module: https://perldoc.perl.org/Time::Piece

The excellent Calendar FAQ at http://www.tondering.dk/claus/calendar.html

Holidays API from https://dev.timeanddate.com/holidays/

 Sample code here: https://gist.github.com/64board/0f9485c4140f62565e02ca941417f68f

Output:

2024-01-01 New Year's Day
2024-01-15 Martin Luther King Jr. Day
2024-02-19 Presidents' Day
2024-05-27 Memorial Day
2024-06-19 Juneteenth
2024-07-04 Independence Day
2024-09-02 Labor Day
2024-10-14 Columbus Day
2024-11-11 Veterans Day
2024-11-28 Thanksgiving Day
2024-12-25 Christmas Day

 

 

2024 Holiday Schedule

 

Date	Holiday
Monday, January 01	New Year’s Day
Monday, January 15	Birthday of Martin Luther King, Jr.
Monday, February 19 *	Washington’s Birthday
Monday, May 27	Memorial Day
Wednesday, June 19	Juneteenth National Independence Day
Thursday, July 04	Independence Day
Monday, September 02	Labor Day
Monday, October 14	Columbus Day
Monday, November 11	Veterans Day
Thursday, November 28	Thanksgiving Day
Wednesday, December 25	Christmas Day

*This holiday is designated as "Washington’s Birthday" in section 6103(a) of title 5 of the United States Code, which is the law that specifies holidays for Federal employees. Though other institutions such as state and local governments and private businesses may use other names, it is our policy to always refer to holidays by the names designated in the law.

Federal Holidays 2023

 

Date	Holiday
Monday, January 02 *	New Year’s Day
Monday, January 16	Birthday of Martin Luther King, Jr.
Monday, February 20 **	Washington’s Birthday
Monday, May 29	Memorial Day
Monday, June 19	Juneteenth National Independence Day
Tuesday, July 04	Independence Day
Monday, September 04	Labor Day
Monday, October 09	Columbus Day
Friday, November 10 *	Veterans Day
Thursday, November 23	Thanksgiving Day
Monday, December 25	Christmas Day

*If a holiday falls on a Saturday, for most Federal employees, the preceding Friday will be treated as a holiday for pay and leave purposes. (See 5 U.S.C. 6103(b).) If a holiday falls on a Sunday, for most Federal employees, the following Monday will be treated as a holiday for pay and leave purposes. (See Section 3(a) of Executive Order 11582, February 11, 1971.) See also our Federal Holidays – "In Lieu Of" Determination Fact Sheet at https://www.opm.gov/policy-data-oversight/pay-leave/work-schedules/fact-sheets/Federal-Holidays-In-Lieu-Of-Determination.

**This holiday is designated as "Washington’s Birthday" in section 6103(a) of title 5 of the United States Code, which is the law that specifies holidays for Federal employees. Though other institutions such as state and local governments and private businesses may use other names, it is our policy to always refer to holidays by the names designated in the law.

Taken from: https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/#url=2023

 

King, Bishop and Knight against King Endgame

64board

Updated: Jul 18, 2022, 10:43 AM 

 

The purpose of this post is to put together some resources about this particular endgame.

I think every chess player should learn this checkmate, it requires several techniques that are present in every day chess play like piece coordination, kings opposition, value of waiting moves, etc.

Although this checkmate is consider as a basic checkmate I think it is the trickiest one, in particular because of the 50 moves rule that will help the defender in case the attacker makes a few mistakes.

The best explanation I found about this checkmate is in the book "Fundamental Chess Endings" by Karsten Muller and Frank Lamprecht. There is an Amazon paperback version and a cheaper Kindle one.

This is a very well explained YouTube video about the KBNK checkmate https://youtu.be/oRK7XLhGz_c

The following link will allow you to practice against the lichess engine. The method they explain is called Deletang's triangles, from the name of the person that formalized it. https://lichess.org/practice/checkmates/knight--bishop-mate/ByhlXnmM/D23EYigW

Personally I prefer Phillidor's method using the Knight's W route.

At chess.com I use the following link to create a custom position and challenge people to play, that way I use the randomness that humans introduce in the game, it is amazing to see how many players don't know how to deliver checkmate, https://www.chess.com/variants/custom

When perfectioning your endgame technique I found the following link to tablebases online very useful: https://www.shredderchess.com/online/endgame-database.html

For example the following endgame requires 30 moves with perfect play:

Since August 2021 chess.com also provide the tablebase feature, see announcement: https://www.chess.com/news/view/chesscom-announces-new-tablebase-feature

(This is a work in progress)

2022 Holiday Schedule

Date	Holiday
Friday, December 31 *	New Year's Day
Monday, January 17	Birthday of Martin Luther King, Jr.
Monday, February 21 **	Washington’s Birthday
Monday, May 30	Memorial Day
Monday, June 20 *	Juneteenth National Independence Day
Monday, July 04	Independence Day
Monday, September 05	Labor Day
Monday, October 10	Columbus Day
Friday, November 11	Veterans Day
Thursday, November 24	Thanksgiving Day
Monday, December 26 *	Christmas Day

*If a holiday falls on a Saturday, for most Federal employees, the preceding Friday will be treated as a holiday for pay and leave purposes. (See 5 U.S.C. 6103(b).) If a holiday falls on a Sunday, for most Federal employees, the following Monday will be treated as a holiday for pay and leave purposes. (See Section 3(a) of Executive Order 11582, February 11, 1971.) See also our Federal Holidays – "In Lieu Of" Determination Fact Sheet at https://www.opm.gov/policy-data-oversight/pay-leave/work-schedules/fact-sheets/Federal-Holidays-In-Lieu-Of-Determination.

**This holiday is designated as "Washington’s Birthday" in section 6103(a) of title 5 of the United States Code, which is the law that specifies holidays for Federal employees. Though other institutions such as state and local governments and private businesses may use other names, it is our policy to always refer to holidays by the names designated in the law.

https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/#url=2022