convert yaml to json in ruby

yaml_to_json.rb

#!/usr/bin/ruby
# Quick and easy way to convert from yaml to json with pretty format
# Usage:
# Example 1:
# 
# # Explicitly give the output filename
# ./yaml_to_json.rb input_file/name.yaml outputfile/name.json
# 
# Example 2:
# 
# # Will implicitly use the input file name with .json extension
# ./yaml_to_json.rb inputfilename.yaml
# 
# Example 3:
# 
# # Also works for .yml extension
# ./yaml_to_json.rb inputfilename.yml
# 

require 'json'
require 'yaml'

input_filename = ARGV[0]
output_filename = ARGV[1] || input_filename.gsub(/(yml|yaml)$/, 'json')

input =  JSON.pretty_generate(YAML.load(File.read(input_filename)))

File.open(output_filename, 'w') do |out|
  out.write input
end