wrote README

README

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+Bdb
+===
+
+Your need first this library:
+
+http://github.com/DenisKnauf/bdb
+
+Download
+========
+
+via git:
+
+	git clone git://github.com/DenisKnauf/sbdb.git
+
+Installation
+============
+
+	cd sbdb
+	gem install sbdb.gemspec
+
+Documentation
+=============
+
+Doesn't exist yet.
+
+Usage
+=====
+
+First, open environment and database
+
+	Dir.mkdir 'newenv'  rescue Errno::EEXIST
+	env = SBDB::Env.new 'newenv', SBDB::CREATE
+	db = env.open SBDB::Btree, 'newdb.db', 'mynewdb', SBDB::CREATE
+
+It works nearly like a Ruby-Hash:
+
+	db['key'] = 'value'
+	db['key']		# => 'value'
+	db.to_hash		# => {'key'=>'value'}
+	db.map {|k, v| [k, v].join ' => '}		# => ["key => value"]
+	db.count		# => 1
+
+*SBDB::DB#each* uses a *SBDB::Cursor*:
+
+	cursor = db.cursor
+	cursor.each {|k,v| puts "#{k}: ${v}" }
+
+Don't forget to close everything, you opened!
+
+	cursor.close
+	db.close
+	env.close
+
+But you can use a *lambda* to ensure to close everything:
+
+	SBDB::Env.new( 'newenv', SBDB::CREATE) do |env|
+		env.open SBDB::Btree, 'newdb.db', 'mynewdb', SBDB::CREATE do |db|
+			db.to_hash
+		end
+	end
+
+*SBDB::DB#to_hash* creates a cursor and close it later.