```ruby
require File.dirname(__FILE__) + '/../../../spec_helper'
require File.dirname(__FILE__) + '/../fixtures/classes'
require 'socket'

describe "Socket#for_fd given a file descriptor" do
  it "adopts that descriptor into a new Socket object" do
    begin
      server = TCPServer.new("0.0.0.0", SocketSpecs.port)
      client = TCPSocket.open("0.0.0.0", SocketSpecs.port)
      new_sock = Socket.for_fd(client.fileno)

      # TODO: RSpec uses #send internally when calling #should == something
      # but as Socket#send does not do what RSpex expects it to do,
      # it fails horriby. RSpec should be using #__send__
      new_sock.should_not be_nil
      new_sock.class.should == Socket
      new_sock.fileno.should == client.fileno

      new_sock.write("foo")
      client.write("bar")
      host = server.accept
      host.read(3).should == "foo"
      host.read(3).should == "bar"
    ensure
      if (server && !server.closed?)
        server.close
      end
      if (client && !client.closed?)
        client.close
      end
      if (new_sock && !new_sock.closed?)
        begin
          new_sock.close
        rescue Errno::EBADF
        end
      end
    end
  end

  it "raises error for a bad descriptor" do
    lambda { Socket.for_fd(9999999) }.should raise_error
  end
end

```

Use 127.0.0.1 instead of 0.0.0.0, uniformly in all socket specs.
user
```ruby
require File.dirname(__FILE__) + '/../../../spec_helper'
require File.dirname(__FILE__) + '/../fixtures/classes'
require 'socket'

describe "Socket#for_fd given a file descriptor" do
  it "adopts that descriptor into a new Socket object" do
    begin
      server = TCPServer.new("127.0.0.1", SocketSpecs.port)
      client = TCPSocket.open("127.0.0.1", SocketSpecs.port)
      new_sock = Socket.for_fd(client.fileno)

      # TODO: RSpec uses #send internally when calling #should == something
      # but as Socket#send does not do what RSpex expects it to do,
      # it fails horriby. RSpec should be using #__send__
      new_sock.should_not be_nil
      new_sock.class.should == Socket
      new_sock.fileno.should == client.fileno

      new_sock.write("foo")
      client.write("bar")
      host = server.accept
      host.read(3).should == "foo"
      host.read(3).should == "bar"
    ensure
      if (server && !server.closed?)
        server.close
      end
      if (client && !client.closed?)
        client.close
      end
      if (new_sock && !new_sock.closed?)
        begin
          new_sock.close
        rescue Errno::EBADF
        end
      end
    end
  end

  it "raises error for a bad descriptor" do
    lambda { Socket.for_fd(9999999) }.should raise_error
  end
end

```
assistant