From: Jeremy Bopp <jeremy@...>
Date: 2011-01-26T13:00:19+09:00
Subject: Re: writing on yaml file

On 01/25/2011 07:09 PM, Kamarulnizam Rahim wrote:
> Hi guys,
> 
> Is it possible for me to write on existing yaml file (i.e add contents
> or change contents) using ruby prgramming? Is there any parser available
> out there?

The standard library defines the YAML class which can parse and emit
YAML documents.  There are quite a few examples out there.  I tried a
couple from here that seemed to work:

http://yaml4r.sourceforge.net/doc/page/examples.htm

Some code to get you started:

require 'yaml'
# Load the file.
yaml = YAML.load_stream(File.open('myfile.yaml'))
# Add a new key-value pair to the root of the first document.
yaml.documents[0]['new_key'] = 'new_value'
File.open('myfile.yaml', 'w') do |file|
  file.write(yaml.emit)
end

The above code assumes that you have a valid YAML file in myfile.yaml.
the first document in that file must have key-value pairs at the root.

-Jeremy