# Notes on working with IO objects

require 'pp'

<<-MD
  # IO

  The basis for all input and output in Ruby. It will convert pathnames between different OS conventions, if possible.

  ## Methods of Interest

  * .binread
  * .binwrite
  * .copy_stream
  * .new
  * .open
  * .pipe
  * .read
  * .readlines
  * .write
  * #chars
  * #close
  * #each, #each_byte, #each_char, #each_line
  * #eof
  * #lines
  * #readbyte, #readchar, #readline, #readlines
  * #rewind
  * #to_i
  * #to_io
  * #write
MD

<<-MD
  # File
MD

# write to file
filename = "todo.txt"
# file = File.open(filename, "w") # or
file = open(filename, "w")
file.puts "Wash dishes"
file.puts "Take a walk"
file.puts "Create hardware startup"
file.close

# write to file - block notation
filename = "groceries.txt"
File.open(filename, "w") do |file|
  file.puts "hummus"
  file.puts "carrots"
  file.puts "avocados"
end

# read from file - block notation
puts "#{filename} contains:"
File.open(filename, "r") do |file|
  puts file.read
end

# read from file - lines into array
lines = File.open(filename, "r").readlines
puts "Reading #{filename} with the #readlines method returns:"
PP.pp lines

# checking for existence
file_check = File.exists?(filename)
puts "Does #{filename} exist? #{file_check ? 'yes' : 'no'}"

# getting the path of a the current file
path = File.dirname(__FILE__)
puts "The file executing this code is located at #{path}"


<<-MD
  # Dir

  "Directory streams representing directories in the filesystem."

  ## Methods of Interest

  * Dir[string] - same as Dir.glob(string)
  * .delete
  * .exists?
  * .foreach
  * .home
  * #path
  * #read
  * #rewind
MD

# creating a directory
Dir.mkdir("temp") unless File.exists?("temp")

# file count
home = Dir.home
file_count = Dir.glob("#{home}/*").length
puts "There are #{file_count} files in the root of your home directory"

# recursive file count
file_count = Dir.glob("#{home}/**/*").length
puts "There are #{file_count} files within your home directory"

# file count by type
file_count = Dir.glob("#{home}/**/*.{pdf,PDF}").size
puts "There are #{file_count} PDFs within your home directory"