Saving Hashes to File on Ruby

How do I write the contents of a hash to a file in Ruby?

This should work for you. I would recommend reading up more on Files and iterating through hashes yourself first though.

yourfile = "/some/path/file.txt"
File.open(yourfile, 'w') do |file|
  character.each{ |k, v| file.write("#{k}: #{v}\n") }
end

Reading a hash from a file on disk

The proper way to save simple data structures to a file is to serialize them. In this particular case, using JSON is probably a good choice:

# save hash to file:
f.write MultiJson.dump(my_hash)

# load it back:
p MultiJson.load(file_contents)

Keep in mind that JSON is only able to serialize simple, built-in data types (strings, numbers, arrays, hashes and the like). You will not be able to serialize and deserialize custom objects this way without some additional work.

If you don't have MultiJson, try it with JSON instead.

Ruby on Rails write Hash to file without : and = values

As I said in comments, you have to do this manually. Use hash.map to get key/value pairs and format them accordingly, join using commas, then add the curlies around the result. I use #to_json as a shortcut to add quotes to strings but not to integers.

hash = {emp_id:15, emp_name:"Test", emp_sal:1800, emp_currency:"USD"}

require 'json'
result = '{' + hash.map { |k, v| "#{k}:#{v.to_json}" }.join(', ') + '}'

puts result
# => {emp_id:15, emp_name:"Test", emp_sal:1800, emp_currency:"USD"}

Note that this only works on a single level. If you have nesting, a recursive function will be needed.

How do I save settings as a hash in a external file?

The most common way to store configuration data in Ruby is to use YAML:

settings.yml

user1:
  path: /
  days: 5

user2:
  path: /tmp/
  days: 3

Then load it in your code like this:

require 'yaml'
settings = YAML::load_file "settings.yml"
puts settings.inspect

You can create the YAML file using to_yaml:

File.open("settings.yml", "w") do |file|
  file.write settings.to_yaml
end

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That said, you can include straight Ruby code also, using load:

load "settings.rb"

However, you can't access local variables outside the file, so you would have to change your code to use an instance variable or a global variable:

settings.rb

SETTINGS = { 
 'user1' => { 'path' => '/','days' => '5' },
 'user2' => { 'path' => '/tmp/','days' => '3' }
}
@settings = { 'foo' => 1, 'bar' => 2 }

Then load it thus:

load "settings.rb"
puts SETTINGS.inspect
puts @settings.inspect

Loop through a hash and save to a different row

Try this:

CSV.generate(col_sep: ';', headers: LOG_HEADERS, encoding: 'UTF-8', write_headers: true) do |csv|
  hsh.each do |key,value|
    row = []
    value.each do |v|
      row << "{#{key}: #{v}}"
    end
    csv << row
  end
end

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