getting error message while generating rails

roshu@thinkpad:~/jaan$ sudo rails g
/usr/local/lib/ruby/1.9.1/yaml.rb:84:in `<top (required)>':
It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your ruby.
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/rubygems_integration.rb:214:in `block in replace_gem': Please install the sqlite3 adapter: `gem install activerecord-sqlite3-adapter` (sqlite3 is not part of the bundle. Add it to Gemfile.) (LoadError)
	from /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/connection_adapters/sqlite3_adapter.rb:3:in `<top (required)>'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:251:in `require'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:251:in `block in require'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:236:in `load_dependency'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:251:in `require'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/connection_adapters/abstract/connection_specification.rb:50:in `resolve_hash_connection'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/connection_adapters/abstract/connection_specification.rb:41:in `resolve_string_connection'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/connection_adapters/abstract/connection_specification.rb:25:in `spec'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/connection_adapters/abstract/connection_specification.rb:130:in `establish_connection'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/railtie.rb:88:in `block (2 levels) in <class:Railtie>'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/lazy_load_hooks.rb:26:in `block in on_load'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/lazy_load_hooks.rb:25:in `each'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/lazy_load_hooks.rb:25:in `on_load'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/railtie.rb:80:in `block in <class:Railtie>'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/initializable.rb:30:in `instance_exec'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/initializable.rb:30:in `run'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/initializable.rb:55:in `block in run_initializers'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/initializable.rb:54:in `each'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/initializable.rb:54:in `run_initializers'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/application.rb:136:in `initialize!'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/railtie/configurable.rb:30:in `method_missing'
	from /home/roshu/jaan/config/environment.rb:5:in `<top (required)>'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:251:in `require'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:251:in `block in require'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:236:in `load_dependency'
	from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/dependencies.rb:251:in `require'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/application.rb:103:in `require_environment!'
	from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.16/lib/rails/commands.rb:25:in `<top (required)>'
	from script/rails:6:in `require'
	from script/rails:6:in `<main>'