File Handling

File Handling

Instruction

Files allow you to store data persistently.
In this task you will write a simple file reading program to read multiple lines using a loop printing each line read to the terminal screen.
To explore this topic, we will modify a Terminal program that will, when complete:
■ Open a file and write a number of records to the file. Close the file.
■ Open a file and loop according to the number of records to read in each record.
■ Print each record that is read (as they are read).
■ Use the code provided (from this task’s resources in Doubtfire) to get started, using this code complete the following:

1. Open and look at the code in the Resources for the basic code for reading and writingthe records from files.
The functionality of this code is basically correct, but the code can be improved in design and implementation, these are the modifications you will make.
2. Make the following modifications the basic_read_write.rb program so that it:
• Uses a loop in read_data_from_file, with the loop controlled by the number at the start of the file.
• Improve the functional decomposition by removing as many lines of code from main as possible, yet retaining good structure.

First. Open a File and start to write the data.

def writingfileConfim()
  a_file = File.new("listOfName.txt", "w") 
  if a_file  #if nil this test will be false
    write_data_to_file(a_file)
    a_file.close
  else
    puts "Unable to open file to write!"
  end
end

Second. Writes the number of lines then each line as a string.

 def write_data_to_file(a_file)
  count = a_file.puts.to_i
  #a_file.puts('5')
  for count in 0..0
   a_file.puts('Fred')
   a_file.puts('Sam')
   a_file.puts('Jill')
   a_file.puts('Jenny')
   a_file.puts('Zorro')
  end

Thirds. Open a File for reading data.

def readingFileConfirm()
  a_file = File.new("listOfName.txt", "r")
  if a_file  #if nil this test will be false
    read_data_from_file(a_file)
    a_file.close
  else
    puts "Unable to open file to read!"
  end
end

Fifth. Reads in each line. It uses a loop which repeats according to the number or lines in the File
which is given in the first line of th File.

 def read_data_from_file(a_file)
  count = a_file.gets.to_i # count = 0
  for count in 0..0
    puts count.to_s #head number
    index = 0 #sub number
    while (index <= 4 )
     puts "#{index}." + a_file.gets 
     index += 1
    end
    count += 1
  end
end

Sixth. Excute

def main
  writingfileConfim()
  readingFileConfirm()
end