YAML Ain't Markup Language

This module provides a Ruby interface for data serialization in YAML format.

You can choose from one of two YAML engines that ship with Ruby 1.9. By default Psych is used but the old unmaintained Syck may chosen.


Working with YAML can be very simple, for example:

require 'yaml' # STEP ONE, REQUIRE YAML!
# Parse a YAML string
YAML.load("--- foo") #=> "foo"

# Emit some YAML
YAML.dump("foo")     # => "--- foo\n...\n"
{ :a => 'b'}.to_yaml  # => "---\n:a: b\n"


Do not use YAML to load untrusted data. Doing so is unsafe and could allow malicious input to execute arbitrary code inside your application. Please see doc/security.rdoc for more information.


Syck was the original for YAML implementation in Ruby's standard library developed by why the lucky stiff.

If you prefer, you can still use Syck by changing the YAML::ENGINE like so:

YAML::ENGINE.yamler = 'syck'
# switch back to the default Psych
YAML::ENGINE.yamler = 'psych'

In older Ruby versions, ie. <= 1.9, Syck is still provided, however it was completely removed with the release of Ruby 2.0.0.

More info

For more advanced details on the implementation see Psych, and also check out yaml.org for spec details and other helpful information.

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