Exercise 7

• https://dev.to/lofiandcode/ruby-puts-vs-print-vs-p-vs-pp-vs-awesome-5akl
• https://www.rubyguides.com/2018/10/puts-vs-print

Exercise 11

• https://rubyreferences.github.io/rubyref/appendix-a.html#io-and-strings

Exercise 13

ruby ex13.rb 12 17 29

• https://flatironschool.com/blog/a-short-explanation-of-argv
• the name of the called script

Exercise 16

ruby ex16.rb test.txt

• https://thoughtbot.com/blog/io-in-ruby#the-io-class
• https://thoughtbot.com/blog/io-in-ruby#file
• https://rubyapi.org/3.1/o/file#method-c-truncate
• https://rubyapi.org/3.1/o/io#method-i-seek
• https://stackoverflow.com/questions/27977368/seek-to-0-or-use-rewind-method

Exercise 17

echo "This is a test file." > test.txt

ruby ex17.rb test.txt new_file.txt

• https://rubyapi.org/3.1/o/file#method-c-exist-3F
• https://stackoverflow.com/questions/8590098/how-to-check-for-file-existence

Exercise 18

• https://www.justinweiss.com/articles/fun-with-keyword-arguments
• https://github.com/JuanitoFatas/what-do-you-call-this-in-ruby

Exercise 20

ruby ex20.rb test.txt

ri File#seek

• https://rubyapi.org/3.1/o/io#method-i-readline

Exercise 24

• https://infinum.com/blog/multiline-strings-ruby-2-3-0-the-squiggly-heredoc

Exercise 25

• https://stackoverflow.com/a/34573127
• https://stackoverflow.com/a/3718649

irb

require "./ex25.rb"
sentence = "All good things come to those who wait."
words = Ex25.break_words(sentence)
sorted_words = Ex25.sort_words(words)
Ex25.print_first_word(words)
Ex25.print_last_word(words)
Ex25.print_first_word(sorted_words)
Ex25.print_last_word(sorted_words)
sorted_words = Ex25.sort_sentence(sentence)
Ex25.print_first_and_last(sentence)
Ex25.print_first_and_last_sorted(sentence)

Exercise 37

• https://learnrubythehardway.org/book/ex37.html + https://docs.ruby-lang.org/en/2.2.0/keywords_rdoc.html + https://rubyreferences.github.io/rubyref/language/globals.html + https://rubyreferences.github.io/rubyref/language/keywords.html

Exercise 41

• https://rubyapi.org/3.0/o/uri#method-c-open
• https://www.rubydoc.info/stdlib/open-uri/OpenURI
• https://github.com/ruby/open-uri
• https://janko.io/improving-open-uri
• https://github.com/yegor256/iri
• https://medium.com/@rainerborene/7-ways-to-encode-urls-in-ruby-c15078a7d6bc

Exercise 46

rake test

• https://github.com/mongrel/mongrel

Exercise 47

cp -r ex46 ex47

mv NAME.gemspec ex47.gemspec

mv bin/NAME bin/ex47

mv tests/test_NAME.rb tests/test_ex47.rb

mv lib/NAME lib/ex47

mv lib/NAME.rb lib/ex47.rb

find . -name "*NAME*" -print