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Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

3014zhangshuo

collection = Array.new(3, 'abc')
collection[0] << 'd'
# all collection item changed, because item value is references
collection # => ['abcd', 'abcd', 'abcd']

collection = Array.new(3) { 'abc' }
collection[0] << 'd'
# pass a block, block executed 3 times, each time "abc" is new string not references
collection # => ['abcd', 'abc', 'abc']

3014zhangshuo

module RubyMemoized
  class Memoizer
    def initialize(content, method)
      @content = content
      @method = method
    end
    
    def call(*args, &block)
      return cache[[args, block]] if cache.has_key?(args, block])
      cache[[args, block]] = content.send(method, *args, &block)

3014zhangshuo

class AddPrimaryKeyToCollections < ActiveRecord::Migration
  def change
    execute "ALTER TABLE collections ADD PRIMARY KEY (id);"
  end
end

# https://stackoverflow.com/questions/18056162/getting-unknown-primary-key-for-table-while-the-id-is-there

3014zhangshuo

class FileIO < StringIO
  def initialize(stream, filename)
    super(stream)
    @original_filename = filename
  end
  
  attr_reader :original_filename
end

# https://makandracards.com/makandra/50526-fileio-writing-strings-as-carrierwave-uploads

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var sum = function (a, b) {
  return a + b;
}

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def var(_);end

var name = "z"

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// 🔥 Node 7.6 has async/await! Here is a quick run down on how async/await works

const axios = require('axios'); // promised based requests - like fetch()

function getCoffee() {
  return new Promise(resolve => {
    setTimeout(() => resolve('☕'), 2000); // it takes 2 seconds to make coffee
  });
}

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git branch | wc -l

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# Access number
cat production.log | grep "^Processing" | wc | awk '{print $1}'

# Each IP access number
cat production.log | grep “^Processing” | awk ‘{print $4}’ | uniq -c 

# Independent IP number
cat production.log | grep "^Processing" | awk '{print $4}' | uniq | wc | awk '{print $1}'
cat production.log | grep “^Processing” | awk ‘{print $4}’ | uniq | wc -l