Add bin/jekyll2 and initial BuildCommand

The `BuildCommand` class is responsible for handling the building of the site.
It can also optionally watch for changes to files and regenerate the site if
needed.

The `Command` class holds any methods which are used by any command
implementation.

bin/jekyll2

@@ -0,0 +1,31 @@
+#!/usr/bin/env ruby
+
+$:.unshift File.join(File.dirname(__FILE__), *%w{ .. lib })
+
+require 'commander/import'
+require 'jekyll'
+
+# Details about Jekyll
+program :name, 'jekyll'
+program :version, Jekyll::VERSION
+program :description, 'Jekyll is a blog-aware, static site generator in Ruby'
+
+# Global options available to every command
+global_option '-s', '--source DIR', String, 'Source directory'
+global_option '-d', '--destination DIR', String, 'Destination directory'
+
+# Build command
+#
+# Args:
+#   --source
+#   --destination
+#   --watch
+command :build do |c|
+  c.syntax = 'jekyll build [options]'
+  c.description = 'Build...'
+  c.option '-w', '--watch', 'Watch for changes and rebuild'
+  c.action do |args, options|
+    options.default :watch => false
+    Jekyll::BuildCommand.process(options)
+  end
+end

lib/jekyll.rb

@@ -41,6 +41,9 @@ require 'jekyll/errors'
 require 'jekyll/plugin'
 require 'jekyll/converter'
 require 'jekyll/generator'
+require 'jekyll/command'
+
+require_all 'jekyll/commands'
 require_all 'jekyll/converters'
 require_all 'jekyll/generators'
 require_all 'jekyll/tags'

lib/jekyll/command.rb

@@ -0,0 +1,14 @@
+module Jekyll
+
+  class Command
+    def self.globs(source)
+      Dir.chdir(source) do
+        dirs = Dir['*'].select { |x| File.directory?(x) }
+        dirs -= ['_site']
+        dirs = dirs.map { |x| "#{x}/**/*" }
+        dirs += ['*']
+      end
+    end
+  end
+
+end

lib/jekyll/commands/build.rb

@@ -0,0 +1,77 @@
+module Jekyll
+
+  class BuildCommand < Command
+    def self.process(options)
+      opts = {}
+      options.__hash__.map do |k,v|
+        opts[k.to_s] = v
+      end
+
+      opts = Jekyll.configuration(opts)
+      site = Jekyll::Site.new(opts)
+
+      source = opts['source']
+      destination = opts['destination']
+
+      if opts['watch']
+        self.watch(site, source, destination)
+      else
+        self.build(site, source, destination)
+      end
+    end
+
+    # Private: Build the site from source into destination.
+    #
+    # site - A Jekyll::Site instance
+    # source - A String of the source path
+    # destination - A String of the destination path
+    #
+    # Returns nothing.
+    def self.build(site, source, destination)
+      puts "Building site: #{source} -> #{destination}"
+      begin
+        site.process
+      rescue Jekyll::FatalException => e
+        puts
+        puts "ERROR: YOUR SITE COULD NOT BE BUILT:"
+        puts "------------------------------------"
+        puts e.message
+        exit(1)
+      end
+      puts "Successfully generated site: #{source} -> #{destination}"
+    end
+
+    # Private: Watch for file changes and rebuild the site.
+    #
+    # site - A Jekyll::Site instance
+    # source - A String of the source path
+    # destination - A String of the destination path
+    #
+    # Returns nothing.
+    def self.watch(site, source, destination)
+      require 'directory_watcher'
+
+      puts "Auto-Regenerating enabled: #{source} -> #{destination}"
+
+      dw = DirectoryWatcher.new(source)
+      dw.interval = 1
+      dw.glob = self.globs(source)
+
+      dw.add_observer do |*args|
+        t = Time.now.strftime("%Y-%m-%d %H:%M:%S")
+        puts "[#{t} regeneration: #{args.size} files changed"
+        site.process
+      end
+
+      dw.start
+
+      trap("SIGINT") do
+        puts "Stopping auto-regeneration..."
+        exit 0
+      end
+
+      loop { sleep 1000 }
+    end
+  end
+
+end