Yapcheekian

https://stackoverflow.com/questions/3324643/processes-threads-green-threads-protothreads-fibers-coroutines-whats-the

https://stackoverflow.com/questions/46864623/which-of-coroutines-goroutines-and-kotlin-coroutines-are-faster

Yapcheekian

var arrNum [5]int // this is an array
var sliceNum []int // this is a slice

fmt.Println(arrNum) // [5]int{0,0,0,0,0} array have initial value of zero value
fmt.Println(sliceNum) // []int(nil) slice have initial value of nil value

sliceNum == nil // true

arrNum[0] = 1 // ok
sliceNum[0] = 1 // compile time error because you cannot assign values to nil

Yapcheekian

#!/usr/bin/env bash
# https://mp.weixin.qq.com/s?__biz=MzA4MzIwNTc4NQ==&mid=2247484821&idx=1&sn=aaa173a8b913cc759c56efe05d2c15ad&chksm=9ffb4e63a88cc7755ca720b3886946245246d8e57687cf209ad47f61a186cc290c04ef57fc91&scene=21#wechat_redirect

function e_net() {
  set -eu
  pod=`kubectl get pod ${pod_name} -n ${namespace} -o template --template='{{range .status.containerStatuses}}{{.containerID}}{{end}}' | sed 's/docker:\/\/\(.*\)$/\1/'`
  pid=`docker inspect -f {{.State.Pid}} $pod`
  echo -e "\033[32m Entering pod netns for ${namespace}/${pod_name} \033[0m\n"
  cmd="nsenter -n -t ${pid}"
  echo -e "\033[32m Execute the command: ${cmd} \033[0m"

Yapcheekian

docker run -it --rm -u yap ubuntu /bin/bash # run as non-root user

docker run -it --rm --security-opt=no-new-privileges ubuntu /bin/bash

docker run -it --rm --cap-drop all --cap-add NET_ADMIN ubuntu /bin/bash

docker run -it --rm --read-only --tmpfs /opt ubuntu /bin/bash

Yapcheekian

func selectionSort(items []int) {
	for x := 0; x < len(items) - 1; x++ {
		min := x
		for y := x+1; y < len(items); y++ {
			if items[y] < items[min] {
				min = y
			}
		}
		items[x], items[min] = items[min], items[x]
	}

Yapcheekian

PUT /_template/fluentbit
{
  "fluenbit" : {
    "order" : 0,
    "index_patterns" : [
      "fluentbit-*"
    ],
    "settings" : {
      "index" : {
        "number_of_shards" : "10"

Yapcheekian

kubectl get certificaterequest
kubectl describe certificaterequest X
kubectl get order
kubectl describe order X
kubectl get challenge
kubectl describe challenge X

Yapcheekian

set -eu

REGION_SEPARATOR='--'

ec2_instance_id="$1"
ssh_user="$2"
ssh_port="$3"
ssh_public_key_path="$4"
ssh_public_key="$(cat "${ssh_public_key_path}")"
ssh_public_key_timeout=60

Yapcheekian

找一個準確值

循環條件: l <= r

縮減搜索空間: l = mid + 1, r = mid - 1

找一個模糊值(比4大的最小數)

循環條件: l < r

縮減搜索空間: l = mid, r = mid - 1 或者 l = mid + 1, r = mid

Yapcheekian

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

int main(int argc, const char * argv[]) {
    srandom(getpid());
    for (int i = 0; i < 16; i++) {
        long int r = random();
        printf("%ld\n", r);