2. Installing Pry
• gem install pry-plus --no-ri --no-rdoc
• Pry-plus contains pry
+ pry-doc (documentation for C methods)
+ pry-debugger (step-through debugger)
+ pry-rescue (opens pry on unhandled exceptions)
+ pry-stack_explorer (call-stack navigation)
+ gist support, bond support, more docs…

3. What’s Pry?
• “like irb, but better”
• Pry is a REPL for Ruby
– (Read-Evaluate-Print Loop)
• An aide for ruby programmers

4. Pry as an aide
• Pry doesn’t solve your problems
• Pry helps you solve your problems
• Lots of simple tools to make your life better

5. Progress
• Introduction
• How do I use the Base64 library?
• Why doesn’t my method work?
• Where did that nil come from?
• What does ordinalize actually do?
• Conclusion

6. How do I use the Base64 library?
$ pry
[1] pry(main)> require „base64‟
=> true
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64

7. How do I use the Base64 library?
$ pry
[1] pry(main)> require „base64‟
=> true
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64

8. How do I use the Base64 library?
$ pry
[1] pry(main)> require „base64‟
=> true
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64

9. How do I use the Base64 library?
$ pry
[1] pry(main)> require „base64‟
=> true
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64

10. How do I use the Base64 library?
$ pry
[1] pry(main)> require „base64‟
=> true
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64

11. How do I use the Base64 library?
$ pry
[1] pry(main)> require „base64‟
=> true
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)>

12. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> (“hi”)
=> “aGk=n”
[4] pry(main)> Base64.decode64(_)
=> “hi”

13. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> Base64.encode64(“hi”)
=> “aGk=n”
[4] pry(main)> Base64.decode64(_)
=> “hi”

14. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> Base64.enc<tab>4(“hi”)
=> “aGk=n”
[4] pry(main)> Base64.decode64(_)
=> “hi”

15. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> Base64.encode64(“hi”)
=> “aGk=n”
[4] pry(main)> Base64.decode64(_)
=> “hi”

16. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> Base64.encode64 “hi”
=> “aGk=n”
[4] pry(main)> Base64.decode64 _
=> “hi”

17. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> Base64.encode64 “hi”
=> “aGk=n”
[4] pry(main)> Base64.decode64 _
=> “hi”

18. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> Base64.encode64 “hi”
=> “aGk=n”
[4] pry(main)> Base64.decode64 _
=> “hi”

19. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[3] pry(main)> Base64.encode64 “hi”
=> “aGk=n”
[4] pry(main)> Base64.decode64 _
=> “hi”

20. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[5] pry(main)>

21. How do I use the Base64 library?
[2] pry(main)> ls Base64
Base64.methods: decode64 encode64
strict_decode64 strict_encode64
urlsafe_decode64 urlsafe_encode64
[5] pry(main)> ? Base64.strict_encode64

22. How do I use the Base64 library?
[5] pry(main)> ? Base64.strict_encode64
From: ~/ruby-1.9.3/lib/ruby/base64.rb
Owner: #<Class:Base64>
Visibility: public
Signature: strict_encode64(bin)
Returns the Base64-encoded version of
bin.
This method complies with RFC 4648.
No line feeds are added.

23. How do I use the Base64 library?
[5] pry(main)> ? Base64.encode64
From: ~/ruby-1.9.3/lib/ruby/base64.rb
Owner: #<Class:Base64>
Visibility: public
Signature: encode64(bin)
Returns the Base64-encoded version of
bin.
This method complies with RFC 2045.
Line feeds are added every 60 characters.

24. How do I use the Base64 library?
• Evaluate ruby code.
• Colour
• Tab-completion
• _ (the last output)
• ls (list methods)
• ? (show-doc)

25. Progress
• Introduction
• How do I use the Base64 library?
• Why doesn’t my method work?
• Where did that nil come from?
• What does ordinalize actually do?
• Conclusion

26. Why doesn’t my method work?
• Broken code can be downloaded if you’re
following along
– (n.b. /raw/ is important!)
curl https://gist.github.com/raw/4463940 >
basic_auth.rb

27. Why doesn’t my method work?
[1] pry(main)> cat basic_auth.rb
require „base64‟
module BasicAuth
def self.encode(username, password)
s = [username, password].join(“:”)
“Basic #{Base64.strict_encode64 s}”
end
def self.decode(header)
base64 = header[/Basic (.*)/, 1]
Base64.decode64 base64.split(“:”)
end
end

28. Why doesn’t my method work?
[1] pry(main)> cat basic_auth.rb
[2] pry(main)> require _file_
=> true
[3] pry(main)> BasicAuth.encode „hi‟, „mum‟
=> “Basic aGk6bXVt”
[4] pry(main)> BasicAuth.decode _
NoMethodError: undefined method `unpack‟ for
[“aGk6bXVt”]:Array
[4] pry(main)> wtf?
0‟

29. Why doesn’t my method work?
[1] pry(main)> cat basic_auth.rb
[2] pry(main)> require _file_
=> true
[3] pry(main)> BasicAuth.encode „hi‟, „mum‟
=> “Basic aGk6bXVt”
[4] pry(main)> BasicAuth.decode _
NoMethodError: undefined method `unpack‟ for
[“aGk6bXVt”]:Array
[4] pry(main)> wtf?
0‟

30. Why doesn’t my method work?
[1] pry(main)> cat basic_auth.rb
[2] pry(main)> require _file_
=> true
[3] pry(main)> BasicAuth.encode „hi‟, „mum‟
=> “Basic aGk6bXVt”
[4] pry(main)> BasicAuth.decode _
NoMethodError: undefined method `unpack‟ for
[“aGk6bXVt”]:Array
[5] pry(main)> wtf?
0‟

31. Why doesn’t my method work?
[4] pry(main)> BasicAuth.decode _
NoMethodError: undefined method `unpack‟ for
[“aGk6bXVt”]:Array
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟

32. Why doesn’t my method work?
[4] pry(main)> BasicAuth.decode _
NoMethodError: undefined method `unpack‟ for
[“aGk6bXVt”]:Array
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode64‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟
[6] pry(main)>

33. Why doesn’t my method work?
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode64‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟
[6] pry(main)> $ BasicAuth.decode

34. Why doesn’t my method work?
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode64‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟
[6] pry(main)> show-source BasicAuth.decode

35. Why doesn’t my method work?
[6] pry(main)> $ BasicAuth.decode
From: ~/basic_auth.rb
Owner: #<Class:BasicAuth>
Visibility: public
Number of lines: 4
def self.decode(header)
base64 = header[/Basic (.*)/, 1]
Base64.decode64 base64.split(“:”)
end

36. Why doesn’t my method work?
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode64‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟
[6] pry(main)> $ BasicAuth.decode
[7] pry(main)> edit-method

37. Why doesn’t my method work?
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode64‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟
[6] pry(main)> $ BasicAuth.decode
[7] pry(main)> edit-method <alt+_>
(on Linux)

38. Why doesn’t my method work?
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode64‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟
[6] pry(main)> $ BasicAuth.decode
[7] pry(main)> edit-method <esc>_
(on a Mac)

39. Why doesn’t my method work?
[5] pry(main)> wtf?
0: ~/ruby-1.9.3/lib/ruby/base64.rb:58 in
`decode64‟
1: ~/basic_auth.rb:10 in `decode‟
2: (pry):3 in `__pry__‟
[6] pry(main)> $ BasicAuth.decode
[7] pry(main)> edit-method BasicAuth.decode

42. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)>

43. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)> <ctrl+r>

44. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)>
(reverse-i-search)`‟:

45. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)> BasicAuth.encode „hi‟, „mum‟
(reverse-i-search)`enc‟

46. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)> BasicAuth.encode „hi‟, „mum‟
=> “Basic aGk6bXVt”
[9] pry(main)>

47. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)> BasicAuth.encode „hi‟, „mum‟
=> “Basic aGk6bXVt”
[9] pry(main)> BasicAuth.decode _
=> [“hi”, “mum”]
[10] pry(main)>

48. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)> BasicAuth.encode „hi‟, „mum‟
=> “Basic aGk6bXVt”
[9] pry(main)> BasicAuth.decode _
=> [“hi”, “mum”]
[10] pry(main)> BasicAuth.decode _out_[3]

49. Why doesn’t my method work?
[7] pry(main)> edit-method BasicAuth.decode
[8] pry(main)> BasicAuth.encode „hi‟, „mum‟
=> “Basic aGk6bXVt”
[9] pry(main)> BasicAuth.decode _
=> [“hi”, “mum”]
[10] pry(main)> BasicAuth.decode _out_[3]
=> [“hi”, “mum”]

50. Why doesn’t my method work?
• wtf? (show backtrace, also _ex_.backtrace)
• $ (show-source)
• edit-method (uses $EDITOR)
• <Alt+_>, <esc>_ (copy last word down)
• <ctrl+r> (search history)
• _file_ (last shown file, also _dir_)
• _out_ (array of all output values, also _in_)

51. Progress
• Introduction
• How do I use the Base64 library?
• Why doesn’t my method work?
• Where did that nil come from?
• What does ordinalize actually do?
• Conclusion

52. Where did that nil come from?
• To follow along get the next file
– (the /raw/ is still important)
• curl https://gist.github.com/raw/4464704 >
post.rb

53. Where did that nil come from?
$ ruby post.rb
post.rb:11:in `make_safe': undefined method
`gsub' for nil:NilClass (NoMethodError)
from post.rb:7:in `safe_title'
from post.rb:19:in `<main>‟
$

54. Where did that nil come from?
$ ruby post.rb
post.rb:11:in `make_safe': undefined method
`gsub' for nil:NilClass (NoMethodError)
from post.rb:7:in `safe_title'
from post.rb:19:in `<main>‟
$ subl post.rb

57. Where did that nil come from?
$ subl post.rb
$

58. Where did that nil come from?
$ subl post.rb
$ ruby post.rb

59. Where did that nil come from?
$ subl post.rb
$ ruby post.rb
From: post.rb @ line 19 :
16: new_post = Post.new(
17: 'title' => 'new post',
18: 'body' => 'your text here')
=> 19: binding.pry # Added for debugging
20: puts new_post.safe_title
[1] pry(main)>

60. Where did that nil come from?
$ subl post.rb
$ ruby post.rb
From: post.rb @ line 19 :
16: new_post = Post.new(
17: 'title' => 'new post',
18: 'body' => 'your text here')
=> 19: binding.pry # Added for debugging
20: puts new_post.safe_title
[1] pry(main)> puts new_post.safe_title

61. Where did that nil come from?
$ subl post.rb
$ ruby post.rb
From: post.rb @ line 19 :
16: new_post = Post.new(
17: 'title' => 'new post',
18: 'body' => 'your text here')
=> 19: binding.pry # Added for debugging
20: puts new_post.safe_title
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil

62. Where did that nil come from?
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil
[2] pry(main)>

63. Where did that nil come from?
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil
[2] pry(main)> cd new_post

64. Where did that nil come from?
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil
[2] pry(main)> cd new_post
[3] pry(#<Post>):1>

65. Where did that nil come from?
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil
[2] pry(main)> cd new_post
[3] pry(#<Post>):1> ls

66. Where did that nil come from?
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil
[2] pry(main)> cd new_post
[3] pry(#<Post>):1> ls
Post#methods: make_safe safe_title
instance variables: @params
locals: _ _dir_ _ex_ _file_ _in_ _out_ _pry_
[4] pry(#<Post>):1>

67. Where did that nil come from?
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil
[2] pry(main)> cd new_post
[3] pry(#<Post>):1> ls
Post#methods: make_safe safe_title
instance variables: @params
locals: _ _dir_ _ex_ _file_ _in_ _out_ _pry_
[4] pry(#<Post>):1> $ safe_title

68. Where did that nil come from?
[1] pry(main)> puts new_post.safe_title
NoMethodError: undefined method `gsub' for nil
[2] pry(main)> cd new_post
[3] pry(#<Post>):1> ls
Post#methods: make_safe safe_title
instance variables: @params
locals: _ _dir_ _ex_ _file_ _in_ _out_ _pry_
[4] pry(#<Post>):1> $ Post#safe_title

69. Where did that nil come from?
[4] pry(#<Post>):1> $ safe_title
From: post.rb @ line 7:
Number of lines: 3
Owner: Post
Visibility: public
def safe_title
make_safe @params[:title]
end
[5] pry(#<Post>):1>

70. Where did that nil come from?
[4] pry(#<Post>):1> $ safe_title
From: post.rb @ line 7:
Number of lines: 3
Owner: Post
Visibility: public
def safe_title
make_safe @params[:title]
end
[5] pry(#<Post>):1> @params

71. Where did that nil come from?
[4] pry(#<Post>):1> $ safe_title
From: post.rb @ line 7:
Number of lines: 3
Owner: Post
Visibility: public
def safe_title
make_safe @params[:title]
end
[5] pry(#<Post>):1> @params
{“title”=>”new post”, “body”=>”your text here”}
[6] pry(#<Post>):1>

72. Where did that nil come from?
[4] pry(#<Post>):1> $ safe_title
From: post.rb @ line 7:
Number of lines: 3
Owner: Post
Visibility: public
def safe_title
make_safe @params[:title]
end
[5] pry(#<Post>):1> @params
{“title”=>”new post”, “body”=>”your text here”}
[6] pry(#<Post>):1> edit --ex

75. Where did that nil come from?
[5] pry(#<Post>):1> @params
{“title”=>”new post”, “body”=>”your text here”}
[6] pry(#<Post>):1> edit --ex
[7] pry(#<Post>):1>

76. Where did that nil come from?
[5] pry(#<Post>):1> @params
{“title”=>”new post”, “body”=>”your text here”}
[6] pry(#<Post>):1> edit --ex
[7] pry(#<Post>):1> .git diff

77. Where did that nil come from?
[7] pry(#<Post>):1> .git diff
diff --git a/post.rb b/post.rb
index d0ed356..057d37c 100644
--- a/post.rb
+++ b/post.rb
@@ -4, 7 +4,7 @@ class Post
end
def safe_title
- make_safe @params[:title]
+ make_safe @params[„title‟]
end
[8] pry(#<Post>):1>

78. Where did that nil come from?
[7] pry(#<Post>):1> .git diff
diff --git a/post.rb b/post.rb
index d0ed356..057d37c 100644
--- a/post.rb
+++ b/post.rb
@@ -4, 7 +4,7 @@ class Post
end
def safe_title
- make_safe @params[:title]
+ make_safe @params[„title‟]
end
[8] pry(#<Post>):1> cd ..

79. Where did that nil come from?
[8] pry(#<Post>):1> cd ..
[9] pry(main)>

80. Where did that nil come from?
[8] pry(#<Post>):1> cd ..
[9] pry(main)> whereami

81. Where did that nil come from?
[8] pry(#<Post>):1> cd ..
[9] pry(main)> whereami
From: post.rb @ line 19 :
16: new_post = Post.new(
17: 'title' => 'new post',
18: 'body' => 'your text here')
=> 19: binding.pry # Added for debugging
20: puts new_post.safe_title
[10] pry(main)>

82. Where did that nil come from?
[8] pry(#<Post>):1> cd ..
[9] pry(main)> whereami
From: post.rb @ line 19 :
16: new_post = Post.new(
17: 'title' => 'new post',
18: 'body' => 'your text here')
=> 19: binding.pry # Added for debugging
20: puts new_post.safe_title
[10] pry(main)> puts new_post.safe_title

83. Where did that nil come from?
[9] pry(main)> whereami
From: post.rb @ line 19 :
16: new_post = Post.new(
17: 'title' => 'new post',
18: 'body' => 'your text here')
=> 19: binding.pry # Added for debugging
20: puts new_post.safe_title
[10] pry(main)> puts new_post.safe_title
new-post
=> nil
[11] pry(main)>

84. Where did that nil come from?
[10] pry(main)> puts new_post.safe_title
new-post
=> nil
[11] pry(main)> puts new_post.safe_title;

85. Where did that nil come from?
[10] pry(main)> puts new_post.safe_title
new-post
=> nil
[11] pry(main)> puts new_post.safe_title;
new-post
[12] pry(main)>

86. Where did that nil come from?
[10] pry(main)> puts new_post.safe_title
new-post
=> nil
[11] pry(main)> puts new_post.safe_title;
new-post
[12] pry(main)> <ctrl+d>

87. Where did that nil come from?
• binding.pry (open pry right here, right now)
• cd (change self)
• whereami
• edit --ex (also, edit -i)
• . (run’s shell commands)
• <ctrl-d> (cd .. or exit)
• ; (suppress output)

88. Progress
• Introduction
• How do I use the Base64 library?
• Why doesn’t my method work?
• Where did that nil come from?
• What does ordinalize actually do?
• Conclusion

89. What does ordinalize actually do?
[1] pry(main)>

90. What does ordinalize actually do?
[1] pry(main)> help gem

91. What does ordinalize actually do?
[1] pry(main)> help gem
Gems
gem-cd Change working directory to
specified gem's directory.
gem-install Install a gem and refresh
the gem cache.
gem-list List and search installed
gems.
gem-open Opens the working directory
of the gem in your editor.
[2] pry(main)>

92. What does ordinalize actually do?
[1] pry(main)> help gem
Gems
gem-cd Change working directory to
specified gem's directory.
gem-install Install a gem and refresh
the gem cache.
gem-list List and search installed
gems.
gem-open Opens the working directory
of the gem in your editor.
[2] pry(main)> help gem-install

93. What does ordinalize actually do?
[1] pry(main)> help gem
Gems
gem-cd Change working directory to
specified gem's directory.
gem-install Install a gem and refresh
the gem cache.
gem-list List and search installed
gems.
gem-open Opens the working directory
of the gem in your editor.
[2] pry(main)> gem-install --help

94. What does ordinalize actually do?
[2] pry(main)> gem-install --help
Usage: gem-install GEM_NAME
Installs the given gem and refreshes the gem
cache so that you can immediately 'require
GEM_FILE'
-h, --help Show this message.
[3] pry(main)>

95. What does ordinalize actually do?
[1] pry(main)> help gem
[2] pry(main)> gem-install --help
[3] pry(main)> gem-install activesupport

96. What does ordinalize actually do?
[3] pry(main)> gem-install activesupport
Fetching: i18n-0.6.1.gem (100%)
Fetching: multi_json-1.5.0.gem (100%)
Fetching: activesupport-3.2.10.gem (100%)
Gem `activesupport` installed.
[4] pry(main)>

97. What does ordinalize actually do?
[3] pry(main)> gem-install activesupport
Fetching: i18n-0.6.1.gem (100%)
Fetching: multi_json-1.5.0.gem (100%)
Fetching: activesupport-3.2.10.gem (100%)
Gem `activesupport` installed.
[3] pry(main)> require „active_support/core_ext‟

98. What does ordinalize actually do?
[3] pry(main)> gem-install activesupport
Fetching: i18n-0.6.1.gem (100%)
Fetching: multi_json-1.5.0.gem (100%)
Fetching: activesupport-3.2.10.gem (100%)
Gem `activesupport` installed.
[4] pry(main)> require „active_support/core_ext‟
=> true
[5] pry(main)>

99. What does ordinalize actually do?
[3] pry(main)> gem-install activesupport
Fetching: i18n-0.6.1.gem (100%)
Fetching: multi_json-1.5.0.gem (100%)
Fetching: activesupport-3.2.10.gem (100%)
Gem `activesupport` installed.
[4] pry(main)>require „active_support/core_ext‟
=> true
[5] pry(main)> 5.ordinalize
=> “5th”
[6] pry(main)>

100. What does ordinalize actually do?
[3] pry(main)> gem-install activesupport
Fetching: i18n-0.6.1.gem (100%)
Fetching: multi_json-1.5.0.gem (100%)
Fetching: activesupport-3.2.10.gem (100%)
Gem `activesupport` installed.
[4] pry(main)>require „active_support/core_ext‟
=> True
[5] pry(main)> 5.ordinalize
=> “5th”
[6] pry(main)> break Fixnum#ordinalize

101. What does ordinalize actually do?
[6] pry(main)> break Fixnum#ordinalize
Breakpoint 1: core_ext/integer/inflections.rb:14
12: # -1001.ordinalize # => "-1001st"
13: #
=> 14: def ordinalize
15: Inflector.ordinalize(self)
16: end
17: end
[7] pry(main)>

102. What does ordinalize actually do?
[6] pry(main)> break Fixnum#ordinalize
Breakpoint 1: core_ext/integer/inflections.rb:14
12: # -1001.ordinalize # => "-1001st"
13: #
=> 14: def ordinalize
15: Inflector.ordinalize(self)
16: end
17: end
[7] pry(main)> 5.ordinalize

103. What does ordinalize actually do?
[7] pry(main)> 5.ordinalize
Breakpoint 1. First hit.
From: core_ext/integer/inflections.rb:14:
=> 14: def ordinalize
15: Inflector.ordinalize(self)
16: end
[8] pry(5)>

104. What does ordinalize actually do?
[7] pry(main)> 5.ordinalize
Breakpoint 1. First hit.
From: core_ext/integer/inflections.rb:14:
=> 14: def ordinalize
15: Inflector.ordinalize(self)
16: end
[8] pry(5)> step

105. What does ordinalize actually do?
[8] pry(5)> step
From: core_ext/integer/inflections.rb:15:
14: def ordinalize
=> 15: Inflector.ordinalize(self)
16: end
[9] pry(5)>

106. What does ordinalize actually do?
[8] pry(5)> step
From: core_ext/integer/inflections.rb:15:
14: def ordinalize
=> 15: Inflector.ordinalize(self)
16: end
[9] pry(5)> step

107. What does ordinalize actually do?
[9] pry(5)> step
From: active_support/inflector/methods.rb:280
279: def ordinalize(number)
=> 280: if (11..13).include?(number.to_i.abs % 100)
281: "#{number}th"
282: else
283: case number.to_i.abs % 10
284: when 1; "#{number}st"
285: when 2; "#{number}nd"
286: when 3; "#{number}rd"
287: else "#{number}th"
288: end
289: end
290: end
[10] pry(ActiveSupport::Inflector)>

108. What does ordinalize actually do?
[9] pry(5)> step
From: active_support/inflector/methods.rb:280
279: def ordinalize(number)
=> 280: if (11..13).include?(number.to_i.abs % 100)
281: "#{number}th"
282: else
283: case number.to_i.abs % 10
284: when 1; "#{number}st"
285: when 2; "#{number}nd"
286: when 3; "#{number}rd"
287: else "#{number}th"
288: end
289: end
290: end
[10] pry(ActiveSupport::Inflector)> next

109. What does ordinalize actually do?
[10] pry(ActiveSupport::Inflector)> next
From: active_support/inflector/methods.rb:283
279: def ordinalize(number)
280: if (11..13).include?(number.to_i.abs % 100)
281: "#{number}th"
282: else
=> 283: case number.to_i.abs % 10
284: when 1; "#{number}st"
285: when 2; "#{number}nd"
286: when 3; "#{number}rd"
287: else "#{number}th"
288: end
289: end
290: end
[11] pry(ActiveSupport::Inflector)>

110. What does ordinalize actually do?
[10] pry(ActiveSupport::Inflector)> next
From: active_support/inflector/methods.rb:283
279: def ordinalize(number)
280: if (11..13).include?(number.to_i.abs % 100)
281: "#{number}th"
282: else
=> 283: case number.to_i.abs % 10
284: when 1; "#{number}st"
285: when 2; "#{number}nd"
286: when 3; "#{number}rd"
287: else "#{number}th"
288: end
289: end
290: end
[11] pry(ActiveSupport::Inflector)> next

111. What does ordinalize actually do?
[11] pry(ActiveSupport::Inflector)> next
From: active_support/inflector/methods.rb:287
279: def ordinalize(number)
280: if (11..13).include?(number.to_i.abs % 100)
281: "#{number}th"
282: else
283: case number.to_i.abs % 10
284: when 1; "#{number}st"
285: when 2; "#{number}nd"
286: when 3; "#{number}rd"
=> 287: else "#{number}th"
288: end
289: end
290: end
[12] pry(ActiveSupport::Inflector)>

112. What does ordinalize actually do?
[11] pry(ActiveSupport::Inflector)> next
From: active_support/inflector/methods.rb:287
279: def ordinalize(number)
280: if (11..13).include?(number.to_i.abs % 100)
281: "#{number}th"
282: else
283: case number.to_i.abs % 10
284: when 1; "#{number}st"
285: when 2; "#{number}nd"
286: when 3; "#{number}rd"
=> 287: else "#{number}th"
288: end
289: end
290: end
[12] pry(ActiveSupport::Inflector)> continue

113. What does ordinalize actually do?
[12] pry(ActiveSupport::Inflector)> continue
=> “5th”
[13] pry(main)>

114. What does ordinalize actually do?
[12] pry(ActiveSupport::Inflector)> continue
=> “5th”
[13] pry(main)> gist -m ActiveSupport::Inflector.ordinalize

115. What does ordinalize actually do?
[12] pry(ActiveSupport::Inflector)> continue
=> “5th”
[13] pry(main)> gist –m ActiveSupport::Inflector.ordinalize
Gist created at https://gist.github.com/465407823ee6182d8833 and
added to clipboard.
[14] pry(main)>

116. What does ordinalize actually do?
[12] pry(ActiveSupport::Inflector)> continue
=> “5th”
[13] pry(main)> gist –m ActiveSupport::Inflector.ordinalize
Gist created at https://gist.github.com/465407823ee6182d8833 and
added to clipboard,
[14] pry(main)> !!!

117. What does ordinalize actually do?
[12] pry (ActiveSupport::Inflector)> continue
=> “5th”
[13] pry(main)> gist –m ActiveSupport::Inflector.ordinalize
Gist created at https://gist.github.com/465407823ee6182d8833 and
added to clipboard,
[14] pry(main)> !!!
$

118. What does ordinalize actually do?
• help (and --help)
• break (pry-debugger)
• step/next/continue (pry-debugger)
• gist
• gem-install (-cd, -open, -list)
• !!! (exit)

119. Progress
• Introduction
• How do I use the Base64 library?
• Why doesn’t my method work?
• Where did that nil come from?
• What does ordinalize actually do?
• Conclusion

120. More good plugins (pry-plus)!
• pry-rescue
– Automatic binding.pry where-ever you have an
unhandled exception or test failure.
• pry-stack_explorer
– Lets you move up-and-down the callstack.
• pry-doc, pry-docmore
– ?/show-doc for C methods, ruby syntax
• bond
– Better-yet tab completion

121. Configuration
• Configuration
– ./.pryrc and ~/.pryrc
• Custom commands
Pry.commands.add_command „test‟ do
output.puts “test”
end
• Documentation on the wiki

122. There’s still more…
He
p
l bitlsa
enrk
roife
aA`
ka
po b
` *** REMOTE GEMS ***
hoa mTeof abf>
ewmayl<`rr tato
p ic d`pfoinu
lS lf nef>mo.
hs shoi o <
o
t .p o o
o n blsat
eop
rifeis
ark`
k`o
A
sbn
a
pr
iA
ltifi
cls`
a
og
`
t
s
-
p
l
c
Cxon
e
t e erm`
lmA- e
i- dife d
f olsl o
a
oh
s
` pry-awesome_print (9.6.5)
d vnobe
c oacxcp
Mtenjt )
ew(e.
n er
io toos
o
c hls
or
to
sa
irifi
y`
As h
t pry-bot (0.0.1)
n hec t ta ue si
idtdrrr ewC dtcaef
f- eRlamdin oortm.
m ch h hls lhn p
oufa o a eu a
v
iy M e
so / re c
es n A
ta
so
iifi
jlsg
`
r
t
s
S hrmdup
lhtlfnescte
swv titrs.
oedhhn
o
ts o
s ne
ia oec qls
ur
Ai
ta
iifx
oe
`
t pry-buffers (1.0.0)
pS tbrP.
yh efe
rcohern
b chi
-kwaty
a ks
r ro
t toe
e qgAxm
umrr `
tr ifig
ir lso
p oa
-a ar
o` e
t
p
- pry-capture (1.0)
aRenfcpc
rpatoets.
esc oete
sin try
i-ax uurn
uep tn
o n
i hia hmdsw`
s - eAo-r
o t lf s
whio ooa u
h
s
`e
rc pry-clipboard (0.1.1)
esRa.
reEce
stPn
Retls
thLaot
ea
wmwsnett
h ihcudccx
e S origro
r odutun
a e nee
ohn. Gt
s
i pry-coolline (0.1.5)
wwafmnn
? tbt otp
f eo tx
tohe se
S ch rc
h ke et
r o
t ci gmdrnGb
G oxt
tt hes H
ss t reirt.
ii eoshiu
a po ot
iyo pry-de (0.1.0)
pry-debugger (0.2.1)
E
d n
t
ig M c
s
i pry-debundle (0.6)
Ciureprssode
!apfsepergyt
e teuro noc
lrnuf acwau
h . i igg s
t b l se ng
e U no u
h
t
f k pS P.
yh y
rn rn
vw
- ov
ee
oo
i i
s s
r r
aee eleuu o
m-Anot le d
nmafimm.
d dip t e
n
i nn -
l in i n e- tdasftttsdtd
raeRduaise e
o olhrhapm
ldhetotcnc h
m oeioh o
e i
cne
l f pry-developer_tools (0.1.1)
ekeira
dtddf
n ul
Ioao
teftoi.
iveltn
hee mr te e t
i l- plti lpp
spmgspm
e Th r .
p omo
o e pry-disasm (0.0.1)
eeEsor e.
dtdedmd
t oiof h
i hdue t
m hca
- tro o
e olTsih.
tl-rgxh
gotgg
elylt
ong
ceii
oan
h pry-doc (0.4.4)
h apahlsr
t dR s:i
swraleay
ihnlydirie
S eet h
o iosnyt
A
.o
paroeop
akibmrs.
lycar tdat
Pslahau
av in
lyg ofi
be l
n
i
r
t e pu1
yg)
rb0
dr
-e
e(
v2
. pry-docmore (0.0.3)
hip tcnnueme.
s -uwnfipfrctuxn
onohtteteu les
wt es urr tp
S oobte i e
h e on- r
h
t h nio btdkt
ertro
reibi.
aap
k en
Sa
o
e pry-editline (1.1.1)
bitfdp
enbis
roieat
as ro
kL en
pe k.
dn pry-em (0.2.1)
nc
Ite
on
rt
p
s
o
i oeter xanP.
cunp eneen
nCug cndr
i i o u hi
tormtdty
ai s
o eo
iiwmnra
Vrc n.a
r ioe.ey`
ed tge
u ai#
or h
i`c
A ntirs rn
isctn es
fEntmr
hua t.
ecc
xle u
uuf
ek r pry-exception_explorer (0.2.3)
hc ahhrr D
s - mS tsfM
oo noeo .
w dwu
m oC e
c nteeinrt e
ehlwes .
E x hn
teehum
xn ttca
et e
un k
ci c r
f pry-full (1.2.0)
hsS hrr eoewtd
s -rotsfmdlso- e
oowu t ri:, m
wh eo hc$ h
u oa oss o
e e ah
c c l.aA eenem
tScitnr td
spnee e.
pxox h
et hl
tutto o
on
i i pry-full18 (0.4)
a tn insnila
ti md tat__c
sweif anfad
V hooddo
e or e rl
m __e
l .
i s pry-gist (5.1.12)
p o3
ye
rc r.)
d(
-m
ov 0
ndu
Ipot
uu
ap
tt
n hdotd nfmd rble
s -cwoen e/ oas
oo hc to tc dlA
wh em r hs /.i:
S u aa oyga
o ao
i lk l ?
e
w pry-git (0.2.3)
< m lx ig rds
.smaAwrate
h ntl n dth
e de a e e
o oi
c o . h.
l >f 'wol
o
f
s hd ryrnvym
s -co odrbco
oo e dvdo r
w s sa p e
mw c r
k e
t sd
i r-
L aoy
e pry-github (0.0.2)
a cr frurein
cwf apfrlst.
S d i,ybttp
t om' teao
h e lPue
o oe ,h
s ox
n
i c pry-hack (0.1)
aoutt hP
sEagn tR
vrfsnmE
etiicf eL
l
i ooo
fpee
-xlnr . pt_r.3
yne
rpe()
e p2
-i xv
co
x l0
o
h dls dg p td p.
s ogl orpd pfmn
e ee eiwmic lt
l Th .in r aoe
m mn l o
- oe B o n ie oenmntcen
cutAptertp
n-pt tiuux.
i c c et
tx e ohc
e o ei
o no
i pry-highlight (0.0.1)
epnnet
ntEexlsin
e tofa
txncotp
ri ette
-orex
e c
c hho pry-multi_debugger (4.8.15)
Ng ar
vy
g
ia
n
t
p enexctp
-pacoren
ttvttet
icenec
xLtofux.
eeeni
o
i hh o pry-nav (0.2.3)
pyonnr dux.
!trnrtivoimen
ys ce k tp
rPnsw les
Si uh s i r
a es m - e
re le ni
of ; o
etpsigsOg)lsi
Pe no ir a
tpeid x At
iorb(Nem:u
xhiuneTr .ie
v d ta q
o p o pu)
ylr
rp.3
pi0
-a
ot
y
v
( pry-note (0.2.9)
etctinigddigrc
aerpnneop
-drP(pliigrrtl.e
t eo nnne
ilnus b)uas
xhyoast ct
En a Ae puruyes
ylrt tyuf
rprprqce
pio iby
- ayhfn
otpsr o
yi o u
Se
n pry-padrino (0.1.2)
emtctg.lsirm
p nurmeo !
-gEep Atg,
tr er qa
ir hn a-r
x dro i:u
o a p
a pry-plus (0.2.0)
up pideeigig .
jmmbgrtsplidlw
o an h bb
t oif ppn s
-J tnrutoan
u u a ne
hk
tc o
, p(4
y0
re
e.)
-v
u
c
s1
nonf a
ewg t.
n in
ig tim
th soo
s er in
Sn cs oeuen
d vpsx
a teap
-e erlrc
u ovid
Mtiyt
ho ieo pry-popularity (0.0.3)
wrwoaiitumy)
si-tesinbgctubbg
hn - nhn ds
ca bnnra r e
tS uoides en
o s ne t
e c i.k n
n
( yedust
rnehdp
tiRcttsixn
ateei
- -oatc
gr ch
y e
h o pry-pretty-numeric (0.1.1)
pry-rails (0.2.2)
Gs
em plr.7
yo
re()
a0
te
sp4
-xv
k
c
_ pry-remote (0.1.6)
g-hwdsd'ic
eca oicpesr
mn rrremy
dgkec d
Ceigyig r.
ntf e
o o
t t
o dndncn
oGwet
wo tae
oolcx
ho
te.
s
'
g-lsmrtgc
eisgafe a
mlenseh
n d m.
a h
tt e e
n
Ia a wa .
r Star e
f eitpm
mcrfht
olu
c
ia pry-remote-auto (1.1.0)
g-dsgs
elnite.
msnm
ah
Lce
tra
sa
ield hsw s
s -oae
ot lm
wf
ar
k
c
Sh pry-remote-em (0.7.3)
uotcn
puet
Gtae
plrx
o' .
h
eo
c
s pry-rescue (0.14)
Cm
oa
mn d
s
mI o ms
i p pmat
or n
ta e
rt d
e
so
- c
m pry-stack_explorer (0.4.7)
n atild m
is mIsbma
a dso d
tmnldc n
o a
c a
- ne .
l pry-syntax-hacks (0.0.6)
pry-theme (0.1.3)
pry-vterm_aliases (1.0.0)
Aa
ie
ls
Ax `
!lsrm
ag
ifio
ore
`
ra
t
p
-
@r
! Ax a
if-
lsl
oe
``
a
t
i
$rw`
Ao-r
au
if o
ls s
oc
h
s
`e
?rw
Ao-c
a`
if o
ls d
oh
s
`

123. Thanks!
• Pry
– http://pryrepl.org
– https://github.com/pry/pry
– irc://irc.freenode.net#pry
• Conrad Irwin
– http://twitter.com/ConradIrwin
– https://github.com/ConradIrwin
– irc://irc.freenode.net/cirwin