sbdb/README.md

Dependencies
============

You need first the [Bdb](http://github.com/ruby-bdb/bdb) and of course [ruby](http://ruby-lang.org).

Download
========

via git:

	git clone git://github.com/ruby-bdb/sbdb

Install
=======

	gem build sbdb.gemspec
	gem install sbdb-*.gem

Usage
=====

First, open environment and database

	require 'sbdb'
	Dir.mkdir 'newenv'  rescue Errno::EEXIST
	env = SBDB::Env.new 'newenv', SBDB::CREATE | SBDB::Env::INIT_TRANSACTION
	db = env.btree 'newdb.db', :flags => 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" } # => ["key => value"]
	db.count    # => 1
	db.each {|k,v| puts "#{k}: #{v}" }

`SBDB::DB#each` uses a `SBDB::Cursor`:

	cursor = db.cursor
	cursor.each {|k,v| puts "#{k}: #{v}" }

**Don't forget to close everything, you've opened!**

	cursor.close
	db.close
	env.close

But you can use a *lambda* to ensure to close everything:

	SBDB::Env.new( 'newenv', SBDB::CREATE | SBDB::Env::INIT_TRANSACTION) do |env|
		env.open SBDB::Btree, 'newdb.db', :flags => SBDB::CREATE do |db|
			db.to_hash
		end
	end

`SBDB::DB#to_hash` creates a cursor and close it later.

Tip:

	Signal.trap 'EXIT', env.method( :close)