Step by Step solution about How to resolve the algorithm Append a record to the end of a text file step by step in the Ruby programming language

The Ruby code snippet demonstrates the use of Ruby Structs to define data structures and then uses these structs to create objects representing user records. The "Gecos" Struct defines five fields: fullname, office, extension, homephone, and email. The "Passwd" Struct defines seven fields: account, password, uid, gid, gecos, directory, and shell.

The to_s method is defined for both structs to convert the fields into a string representation. For the Gecos struct, the to_s method uses the to_a method to create an array of the fields and then joins them into a comma-separated string. For the Passwd struct, the to_s method simply joins the fields into a colon-separated string.

The code creates three instances of the Passwd struct, representing three user records: jsmith, jdoe, and xyz. The user records are then written to a file named append.records.test using the File.open method. The File.open method opens the file in write mode and yields the file object to the block. Within the block, the puts method is used to write the user records to the file.

After writing the user records to the file, the code reads the file using the File.readlines method and prints the contents of the file to the console. This shows the user records before appending the third record.

The code then appends the third user record to the file using the File.open method again, this time in append mode. Within the block, the puts method is used to append the third user record to the file.

After appending the third user record to the file, the code reads the file again using the File.readlines method and prints the contents of the file to the console. This shows the user records after appending the third record.

Gecos = Struct.new :fullname, :office, :extension, :homephone, :email 
class Gecos
  def to_s
    "%s,%s,%s,%s,%s" % to_a
  end
end

# Another way define 'to_s' method
Passwd = Struct.new(:account, :password, :uid, :gid, :gecos, :directory, :shell) do
  def to_s
    to_a.join(':')
  end
end

jsmith = Passwd.new('jsmith','x',1001, 1000, Gecos.new('Joe Smith', 'Room 1007', '(234)555-8917', '(234)555-0077', 'jsmith@rosettacode.org'), '/home/jsmith', '/bin/bash')
jdoe = Passwd.new('jdoe','x',1002, 1000, Gecos.new('Jane Doe', 'Room 1004', '(234)555-8914', '(234)555-0044', 'jdoe@rosettacode.org'), '/home/jdoe', '/bin/bash')
xyz = Passwd.new('xyz','x',1003, 1000, Gecos.new('X Yz', 'Room 1003', '(234)555-8913', '(234)555-0033', 'xyz@rosettacode.org'), '/home/xyz', '/bin/bash')

filename = 'append.records.test'

# create the passwd file with two records
File.open(filename, 'w') do |io|
  io.puts jsmith
  io.puts jdoe
end

puts "before appending:"
puts File.readlines(filename)

# append the third record
File.open(filename, 'a') do |io|
  io.puts xyz
end

puts "after appending:"
puts File.readlines(filename)