Matt Keranen kmatt

ZSH CheatSheet

This is a cheat sheet for how to perform various actions to ZSH, which can be tricky to find on the web as the syntax is not intuitive and it is generally not very well-documented.

Strings

Description	Syntax
Get the length of a string	`${#VARNAME}`
Get a single character	`${VARNAME[index]}`

Learn Go in ~5mins

This is inspired by A half-hour to learn Rust and Zig in 30 minutes.

Basics

Your first Go program as a classical "Hello World" is pretty simple:

First we create a workspace for our project:

Kafka 0.11.0.0 (Confluent 3.3.0) added support to manipulate offsets for a consumer group via cli kafka-consumer-groups command.

List the topics to which the group is subscribed

kafka-consumer-groups --bootstrap-server <kafkahost:port> --group <group_id> --describe

Note the values under "CURRENT-OFFSET" and "LOG-END-OFFSET". "CURRENT-OFFSET" is the offset where this consumer group is currently at in each of the partitions.

Reset the consumer offset for a topic (preview)

Install i3

dnf install i3

Add exec i3 to xinitrc

echo "exec i3" > ~/.xinitrc

	###########################################################
	# How to NEVER use lambdas. An inneficient and yet educa- #
	# tonal [sic] guide to the proper misuse of the lambda #
	# construct in Python 3.x. [DO NOT USE ANY OF THIS EVER] #
	# original by (and apologies to): e000 (13/6/11) #
	# now in Python 3 courtesy of: khuxkm (17/9/20) #
	###########################################################

	## Part 1. Basic LAMBDA Introduction ##
	# If you're reading this, you've probably already read e000's

	import itertools
	from multiprocessing import Process, cpu_count
	from multiprocessing import Pool
	from multiprocessing.pool import ThreadPool


	#
	# CONFIG
	#
	MAX_POOL_PROCESSES=cpu_count()-1

	;; In response to blog post:

	;; https://medium.com/@kasperpeulen/10-features-from-various-modern-languages-that-i-would-like-to-see-in-any-programming-language-f2a4a8ee6727

	;; Run with lumo
	;; https://github.com/anmonteiro/lumo
	;;
	;; # npm install -g lumo-cljs
	;; lumo clojurescript-feature-examples.cljs

	package main

	import (
	"crypto/rand"
	"fmt"
	"math/big"
	"os"
	"sync"
	"time"
	)

	library(plyr); library(dplyr); library(leaflet); library(stringi);
	library(htmltools); library(RColorBrewer); library(rvest)

	# Parse and read storm track data.
	html <- read_html('http://weather.unisys.com/hurricane/atlantic/2016/index.php')
	links <- html_attr(html_nodes(html, "a"), "href")
	links <- links[grep('track.dat', links)]

	track <- select.list(links, title="Select storm:", graphics = FALSE)
	#track <- "MATTHEW/track.dat"

	import java.io.InputStream

	import org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils
	import org.apache.spark.sql.{ DataFrame, Row }

	import org.postgresql.copy.CopyManager
	import org.postgresql.core.BaseConnection

	val jdbcUrl = s"jdbc:postgresql://..." // db credentials elided
	val connectionProperties = {