t11a

### solution 1
def sum_of_digits n
  n.to_s.split('').inject(0) {|sum, i| sum + i.to_i}
end

### solution 2
def sum_of_digits n
  sum = 0
  while n > 0 do
    d = n / 10

t11a

puts "Hello"

t11a

require 'aws-sdk'

AWS.config(
  :access_key_id     => 'your_access_key_id',
  :secret_access_key => 'your_secret_access_key',
  :s3_endpoint       => 's3-ap-northeast-1.amazonaws.com' # see http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region
)

s3 = AWS::S3.new
bucket_name = 'your_bucket/path/to'

t11a

timestamp = ActiveRecord::Base.connection.quote(Time.now.utc)
inserts = []
10**4.times do |i|
  inserts << "('title#{i}', #{i}, #{i}, #{timestamp}, #{timestamp})"
end
sql = "INSERT INTO books (title, serial, price, created_at, updated_at) VALUES #{ inserts.join(',') }"
Book.connection.execute(sql)

t11a

$ ruby -ne 'if $_.split("\t").first.to_i == 1 then puts $_ else  end' test.tsv > 1.tsv

t11a

sql = "LOAD DATA LOCAL INFILE '#{csv_file}' INTO TABLE tblname FIELDS TERMINATED BY ','  LINES TERMINATED BY '\\n'"
ActiveRecord::Base.connection.execute(sql)

t11a

Host step_server
  User          username
  Hostname      xx.xx.xx.xx (Step Server's IP)
  PreferredAuthentications publickey
  IdentityFile  ~/.ssh/private.key
  Port          22
 
### ssh -Wオプションの場合(最近はこっちのほうがオススメらしい)
Host server_in_private
  User     username

t11a

require "rest_client"

def url_shortener(url)
  res=""
  key = "API_KEY_DAYO"
  host = "https://www.googleapis.com/urlshortener/v1/url"
  params = {
    longUrl: url,
    key: key
  }

t11a

class QueueWithSingleStack

  def initialize
    @stack = []
  end

  def enqueue(item)
    @stack << item
  end

t11a

class QueueWithTwoStacks

  def initialize
    @s1 = []
    @s2 = []
  end

  def enqueue(item)
    @s1 << item
  end