Recording, Sharing, TimeSaving -- 一切成本皆时间

#
# Disable "ssh hostname sudo <cmd>", because it will show the password in clear.
#         You have to run "ssh -t hostname sudo <cmd>".
#
Defaults    requiretty

sudo yum -y install epel-release
sudo yum install -y yum-utils
sudo yum-config-manager     --add-repo     https://download.docker.com/linux/centos/docker-ce.repo
# sudo yum list docker-ce --showduplicates | sort -r
sudo yum -y install docker-ce docker-ce-cli containerd.io -y
sudo systemctl start docker
systemctl enable docker

Person = Struct.new(:age, :name, :sex)
me = Person.new(24, 'Spirit', 'male')
me.age  # => 24
me.name = 'Test'
me.name # => 'Test'
me.height # => NoMethodError

p = OpenStruct.new()
p.name='hello'
p.name  # p.name就是hello
p.age=12
p.age   # p.age就是12

class ApplicationController < ActionController::API
  include ActionController::Cookies

def cookies
  # helpers not available in --api mode
  request.cookie_jar
end

2.3.8 :135 >   cache_key='test_key'
 => "test_key"
2.3.8 :136 > Rails.cache.write(cache_key, 10 ,expires_in: 10.seconds)
 => true
2.3.8 :137 > Rails.cache.send(:read_entry, cache_key,{})
 => #<ActiveSupport::Cache::Entry:0x00007fbfa8151750 @value=10, @created_at=1603420143.660662, @expires_in=10.0>
2.3.8 :138 > Rails.cache.read(cache_key)
 => 10
2.3.8 :139 > Rails.cache.increment(cache_key,1, expires_in: 10.seconds)
 => 11
2.3.8 :140 > Rails.cache.read(cache_key)
 => 11
2.3.8 :141 > Rails.cache.send(:read_entry, cache_key,{})
 => #<ActiveSupport::Cache::Entry:0x00007fbfa9003f78 @value=11, @created_at=1603420143.666131, @expires_in=10.0>
2.3.8 :142 >

before_action :output_headers

def output_headers
  headers = request.headers.env.select do |k, _|
    k.downcase.start_with?('http') ||
    k.in?(ActionDispatch::Http::Headers::CGI_VARIABLES)
  end
  headers = headers.sort.to_h
  headers.each do |k,v|
    Rails.logger.info "#{k} = #{v}"
  end
end

Hash.new.sort.to_h

2.7.1 :014 > Integer.ancestors
 => [ActiveSupport::NumericWithFormat, ActiveSupport::ToJsonWithActiveSupportEncoder, Integer, Mongoid::Criteria::Queryable::Extensions::Numeric, Mongoid::Extensions::Integer, BSON::Integer, JSON::Ext::Generator::GeneratorMethods::Integer, MessagePack::CoreExt, Numeric, Comparable, ActiveSupport::Dependencies::ZeitwerkIntegration::RequireDependency, ActiveSupport::ToJsonWithActiveSupportEncoder, Object, PP::ObjectMixin, Mongoid::Criteria::Queryable::Extensions::Object, Mongoid::Extensions::Object, BSON::Object, JSON::Ext::Generator::GeneratorMethods::Object, ActiveSupport::Tryable, ActiveSupport::Dependencies::Loadable, Kernel, BasicObject]
2.7.1 :015 >
2.7.1 :016 > 1.class.ancestors
 => [ActiveSupport::NumericWithFormat, ActiveSupport::ToJsonWithActiveSupportEncoder, Integer, Mongoid::Criteria::Queryable::Extensions::Numeric, Mongoid::Extensions::Integer, BSON::Integer, JSON::Ext::Generator::GeneratorMethods::Integer, MessagePack::CoreExt, Numeric, Comparable, ActiveSupport::Dependencies::ZeitwerkIntegration::RequireDependency, ActiveSupport::ToJsonWithActiveSupportEncoder, Object, PP::ObjectMixin, Mongoid::Criteria::Queryable::Extensions::Object, Mongoid::Extensions::Object, BSON::Object, JSON::Ext::Generator::GeneratorMethods::Object, ActiveSupport::Tryable, ActiveSupport::Dependencies::Loadable, Kernel, BasicObject]
2.7.1 :017 >

2.7.1 :026 > rand(1..10)
 => 10
2.7.1 :027 > rand(1.1..99.99)
 => 22.250780345080248
2.7.1 :028 >
2.7.1 :029 >
2.7.1 :030 > Random.rand(1...10)
 => 1
2.7.1 :031 > Random.rand(1.0...10)
 => 7.646093836025024
2.7.1 :032 >

group :development do
...
  gem 'faker'
...
end

# 生成随机图片
image_size = "#{rand(400...500)}x#{rand(500...600)}"
Faker::LoremFlickr.image(size: image_size, search_terms: ['sports'])

# 生成随机email
Faker::Internet.email

# 生成标题
title = [Faker::Company.name,  Faker::Company.industry].join(' - ')

# 生成描述文字
desc = Faker::Quote.matz
desc = Faker::Hipster.sentences.sample

# 生成随机时间
time = Faker::Time.between(from: DateTime.now - 365, to: DateTime.now + 365, format: :default)

2.7.1 :047 > (1..100).to_a.sample
 => 81
2.7.1 :048 > (1..100).to_a.sample
 => 13
2.7.1 :049 > (1..100).to_a.sample
 => 91
2.7.1 :050 >

validate do |block_key_word|
    existing_record = BlockKeyWord.where(:name => block_key_word.name).first
    unless existing_record.nil? || existing_record.id == block_key_word.id
        block_key_word.errors.add :base, ("关键字-#{block_key_word.name}已存在。")
    end
end

require 'rubyXL'
workbook = RubyXL::Workbook.new
workbook[0].add_cell(0, 0, "写入内容")
workbook.write("#{Rails.root}/tmp/file.xlsx")

URI.join('http://www.81.cn/jmywyl/2020-04/04/content_9784967.htm?from=singlemessage&isappinstalled=0','../../attachement/jpg/site351/20200404/309c236f8da41ff2b3033e.jpg').to_s

validates :name, :uniqueness => { :message => "名字不能重复。" , :scope => :deleted_at}

2.3.8 :060 >   Time.zone
 => #<ActiveSupport::TimeZone:0x00007fe7d4fa9330 @name="Beijing", @utc_offset=nil, @tzinfo=#<TZInfo::DataTimezone: Asia/Shanghai>>
2.3.8 :061 >
2.3.8 :062 >   date_string="2021-01-01 00:00:00"
 => "2021-01-01 00:00:00"
2.3.8 :063 >
2.3.8 :064 >   Time.parse(date_string)
 => 2021-01-01 00:00:00 +0800
2.3.8 :065 >
2.3.8 :066 >   DateTime.parse(date_string)
 => Fri, 01 Jan 2021 00:00:00 +0000
2.3.8 :067 >
2.3.8 :068 >

2.3.8 :073 >   str="你好，世界！"
 => "你好，世界！"
2.3.8 :074 > str.mb_chars
 => #<ActiveSupport::Multibyte::Chars:0x00007f87d3f5a548 @wrapped_string="你好，世界！">
2.3.8 :075 > str.mb_chars.bytes
 => [228, 189, 160, 229, 165, 189, 239, 188, 140, 228, 184, 150, 231, 149, 140, 239, 188, 129]
2.3.8 :076 > str.mb_chars.bytesize
 => 18
2.3.8 :077 > str.mb_chars.limit(5).to_s
 => "你"
2.3.8 :078 > str.mb_chars.limit(6).to_s
 => "你好"
2.3.8 :079 > str.mb_chars.limit(7).to_s
 => "你好"
2.3.8 :080 > str.mb_chars.limit(8).to_s
 => "你好"
2.3.8 :081 > str.mb_chars.limit(9).to_s
 => "你好，"
2.3.8 :082 > str.mb_chars.limit(10).to_s
 => "你好，"
2.3.8 :083 >

gem 'aws-sdk', '~> 3'

bucket="target-bucket-name"
object_name="obj.jpg"

obj = Aws::S3::Object.new(bucket, object_name)
obj.presigned_url(:put, acl: 'public-read')

rvm --create --ruby-version ruby-2.7.1@rails6guide

$ cat .ruby-version
ruby-2.7.1
$
$ cat .ruby-gemset
rails6guide
$

[1,2,3,4,5,6,7,8,9,10].map{|e| e*3 }
# returns [3, 6, 9, 12, 15, 18, 21, 24, 27, 30]

[1,2,3,4,5,6,7,8,9,10].each{|e| print e.to_s+"!" }
# prints "1!2!3!4!5!6!7!8!9!10!"
# returns [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] 

[1,2,3,4,5,6,7,8,9,10].inject{|sum,e| sum += e }
# returns 55

["bar","baz","quux"].inject("foo") {|acc,elem| acc + "!!" + elem }
# returns "foo!!bar!!baz!!quux" 

[1,2,3,4,5,6,7,8,9,10].select{|el| el%2 == 0 }
# returns [2,4,6,8,10]

[1,2,3,4,5,6,7,8,9,10].find{|el| el / 2 == 2 }
# returns 4

[1,2,3,4,5,6,7,8,9,10].reject{|e| e==2 || e==8 }
# returns [1, 3, 4, 5, 6, 7, 9, 10]

string.delete(" \t\r\n")

include ActionView::Helpers::SanitizeHelper
strip_tags(html_string)

src_string="I'm a boy"
regex_string ="[Bb]oy"
regex = Regexp.new regex_string

if src_string =~ regex
    print "Match"
else
    print "MissMatch"
end

response = RestClient::Request.execute(method: :head, url: url, timeout: 10)

url="http://lh.rdcpix.com/00b95cd7bb26ff97392d3fa5c480706cl-f61050563r.jpg"
response = RestClient::Request.execute(method: :head, url: url, timeout: 10)
puts response.headers
=> {:content_type=>"image/jpeg", :content_length=>"342576", :connection=>"keep-alive", :date=>"Thu, 25 Aug 2022 07:29:21 GMT", :last_modified=>"Thu, 26 May 2022 14:15:17 GMT", :etag=>"\"f0f01cc048b5b969abb45b5b3ad951af\"", :accept_ranges=>"bytes", :server=>"AmazonS3", :x_cache=>"Hit from cloudfront", :via=>"1.1 a3c2566f9e36ad3cdf79fc6307fcf566.cloudfront.net (CloudFront)", :x_amz_cf_pop=>"FRA53-C1", :x_amz_cf_id=>"PhcWnxq2z3HtZXXJIMYxltr7-ua08teFX7Ec-3sVJvzYTITCMjXgdQ==", :age=>"32481"}

items.each do |item|
  item.sub_items.select! {|sub_item| sub_item.is_deleted == false}
  item.sub_items.each do |sub_item|
    sub_item.item_children.select! {|item_child| item_child.is_deleted == false}
  end
end

# app/controllers/concerns/orderable.rb
module Orderable
  extend ActiveSupport::Concern

  module ClassMethods
  end

  # A list of the param names that can be used for ordering the model list
  def ordering_params(params)
    # For example it retrieves a list of experiences in descending order of price.
    # Within a specific price, older experiences are ordered first
    #
    # GET /api/v1/experiences?sort=-price,created_at
    # ordering_params(params) # => { price: :desc, created_at: :asc }
    # Experience.order(price: :desc, created_at: :asc)
    #
    ordering = {}
    if params[:sort]
      sort_order = { '+' => :asc, '-' => :desc }

      sorted_params = params[:sort].split(',')
      sorted_params.each do |attr|
        sort_sign = (attr =~ /\A[+-]/) ? attr.slice!(0) : '+'
        model = controller_name.classify.constantize
        if model.attribute_names.include?(attr)
          ordering[attr] = sort_order[sort_sign]
        end
      end
    end
    return ordering
  end
end

# GET /api/v1/experiences
def index
  @experiences = apply_scopes(Experience).
    order(ordering_params(params)).
    # fix N+1 query problem
    includes(:city, :user, :categories).
    all

  render json: @experiences
end

## 排序设置
# 按发布时间排序, 按ID排序, 比如-release_time,+id , -表示倒序，+表示正序
sort_by = params[:sort]

## 例子
#     # GET /api/v1/experiences?sort=-price,created_at
#     # ordering_params(params) # => { price: :desc, created_at: :asc }
#     # Experience.order(price: :desc, created_at: :asc)
ordering = {}
if sort_by.present?
  sort_order = { '+' => :asc, '-' => :desc }
  valid_sort_keys = ["id", "release_time"]

  sorted_params = sort_by.split(',')
  sorted_params.each do |attr|
    sort_sign = (attr =~ /\A[+-]/) ? attr.slice!(0) : '+'
    if valid_sort_keys.include?(attr)
      ordering[attr] = sort_order[sort_sign]
    end
  end
else
  ordering = {"id": "desc"}
end

ordering_string = ""
ordering.each do |k,v|
  if ordering_string.blank?
    ordering_string += "#{k.to_s} #{v.to_s}"
  else
    ordering_string += ",#{k.to_s} #{v.to_s}"
  end
end
ordering_string = "id desc" if ordering_string.blank?

Rails.configuration.database_configuration[Rails.env]

$ irb
2.3.8 :001 > [1,2,3,4].shuffle
 => [1, 4, 2, 3]
2.3.8 :002 > [1,2,3,4].shuffle
 => [1, 3, 2, 4]
2.3.8 :003 > [1,2,3,4].shuffle
 => [2, 3, 1, 4]
2.3.8 :004 >

# 使用ruby版本2.3.0
rvm use ruby-2.3.0

# 创建名为test-for-blog的gemset
rvm gemset create test-for-blog

# 切换当前环境为该gemset
rvm use ruby-2.3.0@rails5

# 在该gemset中进行bundle安装gem
bundle install

[1] pry(main)> [DateTime.parse('2022-01-01 12:00:00'), DateTime.parse('2022-02-01 00:00:00')].max
=> Tue, 01 Feb 2022 00:00:00 +0000
[2] pry(main)> [DateTime.parse('2022-01-01 12:00:00'), DateTime.parse('2022-02-01 00:00:00')].min
=> Sat, 01 Jan 2022 12:00:00 +0000
[3] pry(main)>

[8] pry(main)> [1,2,3,4].insert(1,100)
=> [1, 100, 2, 3, 4]
[9] pry(main)>

> b = [["student","sam"], ["student","george"], ["teacher","matz"]]
 => [["student", "sam"], ["student", "george"], ["teacher", "matz"]]
> b.uniq { |s| s.first }
 => [["student", "sam"], ["teacher", "matz"]]
>
>   b.uniq { |s| true }
 => [["student", "sam"]]
>

## 根据元素某个函数的值来uniq
fruits = %w(orange apple banana)
fruits.uniq(&:size)  => 结果为: ["orange", "apple"]

## 根据元素的类类型来uniq
objects = [1, 2, "a", "b", :c, :d]
objects.uniq(&:class) => 结果为: [1, "a", :c]

## 混合字段来uniq
User类有
- age
- name
- country
三个元素

[david, petter, raphael].uniq { |person| [person.age, person.country] }
上面式子会根据age,country组合来进行uniq

file = 'http://recyclewearfashion.com/stylesheets/page_css/page_css_4f308c6b1c83bb62e600001d.css?1343074150'
File.extname(URI.parse(file).path) # => '.css'

url="https://www.baidu.com/helloworld"
host = URI.parse(url).host rescue ''
url = url.gsub(host, "www.qq.com") if host.present?
## url => https://www.qq.com/helloworld

word = "Now is the,time for'all good people"
word.split(/[\s,']/)
 => ["Now", "is", "the", "time", "for", "all", "good", "people"]

Post.in_order_of(:id, [3, 5, 1])

SELECT "posts".* FROM "posts" ORDER BY CASE "posts"."id" WHEN 3 THEN 1 WHEN 5 THEN 2 WHEN 1 THEN 3 ELSE 4 END ASC

SELECT "posts".* FROM "posts" ORDER BY FIELD("posts"."id", 1, 5, 3) DESC

def self.order_by_ids(ids)
  t = User.arel_table
  condition = Arel::Nodes::Case.new(t[:id])
  ids.each_with_index do |id, index|
    condition.when(id).then(index)
  end
  order(condition)
end

ids=[9,1000,2]
User.where(:id => ids).order("ARRAY_POSITION(ARRAY#{ids.to_s}::int[], id)").pluck(:id)

my_hash = {"a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5}

my_hash.each do |k,v|
   my_hash[k] = v.ordinalize
end

puts my_hash

# 安装urw-base35-fonts-legacy, fonts在/usr/share/X11/fonts/urw-fonts目录下
yum install urw-base35-fonts-legacy

# 修改/etc/ImageMagick-6/type.xml配置文件为使用type-ghostscript.xml
sed -i.bak 's,type-urw-base35.xml,type-ghostscript.xml,g' /etc/ImageMagick-6/type.xml

# 修改 /etc/ImageMagick-6/type-ghostscript.xml为/usr/share/X11/fonts/urw-fonts/
sed -i.bak 's,metrics=",metrics="/usr/share/X11/fonts/urw-fonts/,g' /etc/ImageMagick-6/type-ghostscript.xml
sed -i 's,glyphs=",glyphs="/usr/share/X11/fonts/urw-fonts/,g' /etc/ImageMagick-6/type-ghostscript.xml