Documents can be piped to the nokogiri command line tool

CHANGELOG.rdoc

@@ -7,6 +7,8 @@
   * Node#native_content= allows setting unescaped node contant. #768
   * XPath lookup with namespaces supports symbol keys. #729 (Thanks, Ben Langfeld.)
   * XML::Node#[]= stringifies values. #729 (Thanks, Ben Langfeld.)
+  * bin/nokogiri will process a document from $stdin
+  * bin/nokogiri -e will execute a program from the command line
 
 
 * Bugfixes

bin/nokogiri

@@ -16,6 +16,7 @@ opts = OptionParser.new do |opts|
   opts.separator "Examples:"
   opts.separator "  nokogiri http://www.ruby-lang.org/"
   opts.separator "  nokogiri ./public/index.html"
+  opts.separator "  curl -s http://nokogiri.org | nokogiri -e'p $_.css(\"h1\").length'"
   opts.separator ""
   opts.separator "Options:"
 
@@ -27,6 +28,10 @@ opts = OptionParser.new do |opts|
     encoding = v
   end
 
+  opts.on("-e command", "Specifies script from command-line.") do |v|
+    @script = v
+  end
+
   opts.on("--rng <uri|path>", "Validate using this rng file.") do |v|
     @rng = open(v) {|f| Nokogiri::XML::RelaxNG(f)}
   end
@@ -45,19 +50,29 @@ opts.parse!
 
 uri = ARGV.shift
 
-if uri.to_s.strip.empty?
+if uri.to_s.strip.empty? && $stdin.tty?
   puts opts
   exit 1
 end
 
-@doc = parse_class.parse(open(uri).read, nil, encoding)
+if $stdin.tty?
+  @doc = parse_class.parse(open(uri).read, nil, encoding)
+else
+  @doc = parse_class.parse($stdin, nil, encoding)
+end
+
+$_ = @doc
 
 if @rng
   @rng.validate(@doc).each do |error|
     puts error.message
   end
 else
-  puts "Your document is stored in @doc..."
-  IRB.start
+  if @script
+    eval @script, binding, '<main>'
+  else
+    puts "Your document is stored in @doc..."
+    IRB.start
+  end
 end