One thing that puzzled me as a newbie (disclaimer: I still am) are accessors in Ruby, more commonly known as setters and getters or explicitly described as attr_reader, attr_writer and attr_accessor. Now let’s dive into the code first and describe the concepts of accessors after we’re done with coding. Initializing a Class Let’s say we want to create a class to resemble a Person with a name, and finally let’s try to access that name outside the class:...
Basic usage Where FILENAME is the filename that you want to calculate require 'digest/sha1' Digest::SHA1.hexdigest(FILENAME) More advanced usage Save this code as checkhash.rb, usage: checkhash.rb <filename>. require 'digest/sha1' # Usage: checkhash.rb <filename> filename = ARGV.pop if filename.nil? # if no filename specified then prints help puts 'Please specify the filename to calculate the hash' puts "Usage: #{File.basename($PROGRAM_NAME)} FILENAME" exit end # calculating SHA1 hash def calculate_hash(file) Digest::SHA1.hexdigest(file) end file_hash = calculate_hash(filename) puts "#{filename}: #{file_hash}"