Getting started with ruby

A lightning talk for Eindhoven.rb about getting started with various command-line options for the ruby program.

Transcript

1. Getting started
   with ruby
   Eindhoven.rb #4 — 5 april 2011
   Arjan van der Gaag
   

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2. Getting started
   with Ruby
   Eindhoven.rb #4 — 5 april 2011
   Arjan van der Gaag
   

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3. Getting started
   with Ruby
   Eindhoven.rb #4 — 5 april 2011
   Arjan van der Gaag
   

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4. Getting started
   with ruby
   Eindhoven.rb #4 — 5 april 2011
   Arjan van der Gaag
   

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5. View Slide

6. $ ruby app.rb
   

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7. $ ruby app.rb
   $ ruby -r “mylib” app.rb
   

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8. $ ruby app.rb
   $ ruby -r “mylib” app.rb
   $ ruby -rubygems app.rb
   

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9. $ ruby app.rb
   $ ruby -r “mylib” app.rb
   $ ruby -rubygems app.rb
   $ ruby -I lib app.rb
   

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10. # lib/post.rb
    class Post
    attr_accessor :title, :author
    end
    # app.rb
    require "post"
    get '/' do
    @posts = Post.all
    erb :index
    end
    $ ruby -rubygems -r sinatra -I lib app.rb
    

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12. $ ruby -e ‘puts “Hello, world”’
    

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13. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    

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14. while gets
    # execute app.rb here
    end
    

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15. while $_ = gets
    # execute app.rb here
    end
    

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16. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    

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17. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    

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18. while gets
    # execute app.rb here
    print
    end
    

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19. while $_ = gets
    # execute app.rb here
    print $_
    end
    

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20. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    

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21. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    $ ruby -lpe app.rb
    

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22. while gets
    $_.chomp!
    # execute app.rb here
    print
    end
    

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23. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    $ ruby -lpe app.rb
    

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24. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    $ ruby -lpe app.rb
    $ ruby -pe
    “next unless /{7}/”
    conflicted_file
    

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25. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    $ ruby -lpe app.rb
    $ ruby -pe
    “next unless /{7}/”
    conflicted_file
    $ ruby -an -F, -e ‘puts $F[0]‘
    csv_file
    

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26. while gets
    $F = $_.split $,
    # execute app.rb here
    end
    

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27. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    $ ruby -lpe app.rb
    $ ruby -pe
    “next unless /{7}/”
    conflicted_file
    $ ruby -an -F, -e ‘puts $F[0]‘
    csv_file
    

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28. $ ruby -e ‘puts “Hello, world”’
    $ ruby -n app.rb
    $ ruby -p app.rb
    $ ruby -lpe app.rb
    $ ruby -pe
    “next unless /{7}/”
    conflicted_file
    $ ruby -an -F, -e ‘puts $F[0]‘
    csv_file
    $ ruby -i -p -e
    ‘$_.downcase!’ file
    

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29. #!/usr/bin/env ruby -w
    # Example input:
    #
    # john,secret
    # graham,test
    require 'digest'
    while line = ARGF.gets("\n") do
    parts = line.split ','
    next unless parts[1]
    print line.gsub parts[1],
    Digest::SHA1.hexdigest(parts[1])
    end
    

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30. #!/usr/bin/env ruby -wanp -r digest -F,
    next unless $F[1]
    gsub $F[1],
    Digest::SHA1.hexdigest($F[1])
    

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31. # Read all values in ARGV as files as
    # a single stream OR read from STDIN
    puts ARGF.read
    puts $

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32. - $/ input record separator (default \n)
    - $\ output record separator (default \n)
    - $, output field separator (default nil)
    - $; input field separator (default nil)
    - $_ current line
    - $. number of current line
    - $F result of $_.split($;)
    Ruby globals
    

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33. - OptParse
    - StrScanner
    - OpenStruct
    - Set
    - CSV
    - Find
    - FileUtils
    - Tmpfile
    - Zlib
    - Abbrev
    Know your StdLib
    

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35. $ ruby -h
    

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36. github.com/avdgaag
    @avdgaag
    

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