gistfile1.rb

# To use, put this file, jay.rb, in a directory with the csv files you need to convert. 
# Then just run the following command from the prompt:
# ruby jay.rb [name of file without the .csv]

# Get the libraries you need
require 'csv'
require 'json'


# ARGV[0] gets the name of the first argument you passed from the command line - in this case, the name of the csv file
input_file_name = ARGV[0] + '.csv'

output_file_name = ARGV[0] + '.json'

# Open the files. W+ gives write permission and creates the file if necessary
output_file = File.open(output_file_name, "w+")

# Read the input file (the CSV file)
input_file = File.open(input_file_name, "r")

# Create an empty array to put the resulting hashes in
entry_array = []


# Iterate over each entry in the CSV file (shift removes the first entry in the array, which is your headers)
JSON.parse(CSV.parse(input_file).to_json).shift.each do |entry|
  
  
  # Create a new hash to store the values from the a given CSV array entry and assign the values
  c = Hash.new
  c['Station'] = entry[0]
  c['Time']  = entry[1]
  c['TransactionNumber'] = entry[2]
  c['UPC'] = entry[3]
  c['Product'] = entry[4]
  c['Dept'] = entry[5]
  c['Cashier'] = entry[6]
  c['SalesQty'],  = entry[7]
  c['Unit'] = entry[8]
  c['Amount'] = entry[9]
  c['Tax'] = entry[10]


  # add the resulting hashes to the array of hashes
  entry_array << c

end

# Write the array of hashes to a json file with the same name as the input file, except with the .json extension
output_file.write(entry_array.to_json)