File operations

File Operations

require 'securerandom'
#------------------------------------------------------------------------------------
# Requirement:
# Read original file of 35mb, it should write 25mb of data to duplicate file.
#------------------------------------------------------------------------------------
original = "/Downloads/all/original.txt"
duplicate = "/Downloads/all/duplicate.txt"
MEGABYTE = 25 * 1024

file2 = File.open(duplicate, 'a')

class File
  def each_chunk(chunk_size = MEGABYTE)
    yield read(chunk_size) until eof?
  end
end
count = 0
File.open(original, "rb") do |f|
  f.each_chunk do |chunk| 
  	break if count > 970
  	file2.write("#{chunk}\n")
  	count += 1
  end
end

#------------------------------------------------------------------------------------
# First create a new file 'original.txt' of size 35MB
#------------------------------------------------------------------------------------
# one_megabyte = 2 ** 20 # or 1024 * 1024, if you prefer

# # Note use 'wb' mode to prevent problems with character encoding
# File.open("#{original}", 'wb') do |f|
#   "35".to_i.times { f.write( SecureRandom.random_bytes( one_megabyte ) ) }
# end