haeramkeem

#!/bin/bash

# Change UI mode for Ubuntu 20.04
# Ref: https://superuser.com/a/1139020

# When you want to use GUI X.Org
sudo telinit 5

# When you want to use console
sudo telinit 3

haeramkeem

#!/bin/bash

# To get 'com' from 'maps.google.com' -> parse string to get last field using delimiter
# Ref: https://stackoverflow.com/a/48032204
echo 'maps.google.com' | awk -F. '{print $NF}'

# or
awk -F. '{print $NF}' <<< 'maps.google.com'

haeramkeem

#!/bin/bash

# Ref: https://stackoverflow.com/a/36394262
echo "export LC_ALL=C" >> ~/.bashrc
source ~/.bashrc

haeramkeem

#!/bin/bash

# Ref: https://linux.die.net/man/1/dig

# Get IP of the DNS only
dig www.google.com +short

haeramkeem

#!/bin/bash

# Ref: https://www.digitalocean.com/community/tutorials/how-to-use-journalctl-to-view-and-manipulate-systemd-logs

# Set timezone
#   Get available timezone:
#   $ timedatectl list-timezones
sudo timedatectl set-timezone Asia/Seoul

# View logs

haeramkeem

#!/bin/bash

# Dealing with error: 'ERROR: readlink /var/lib/docker/overlay2: invalid argument'
# In kubernetes or docker

# Have to clear the docker cache
# docker prune will tidy the unused container, images, cache, etc.
docker system prune --all
docker volume prune 

haeramkeem

#!/bin/bash

# Show BGP peering establishment status
sudo calico node status
kubectl describe blockaffinities | grep -E "Name:|Cidr:"
sudo birdc show protocols
sudo birdc show route protocol bgp2

haeramkeem

def convert(input)
  # Trim string
  # @see https://stackoverflow.com/a/1000975
  input.strip! || input

  # Reverse string
  # '!' means modify the value in place
  input.reverse!
  
  # To uppercase string

haeramkeem

test("Expect error for normal function", () => {
    expect(() => {
        someAsyncFunction();
    }).toThrowError('Error message'));
});

test("Expect error for async function", async () => {
    async expect(async () => {
        await someAsyncFunction();
    }).rejects.toThrowError('Error message'));

haeramkeem

#!/bin/bash

sudo ssh-keygen -A