function createWritableStdioStream (fd) {
		  var stream;
		  var tty_wrap = process.binding('tty_wrap');

		  // Note stream._type is used for test-module-load-list.js

		  switch (tty_wrap.guessHandleType(fd)) {
		    case 'TTY':
		      stream = new tty.WriteStream(fd);
		      stream._type = 'tty';

		      // Hack to have stream not keep the event loop alive.
		      // See https://github.com/joyent/node/issues/1726
		      if (stream._handle && stream._handle.unref) {
		        stream._handle.unref();
		      }
		      break;

		    case 'FILE':
		      var fs = require$$0$e;
		      stream = new fs.SyncWriteStream(fd, { autoClose: false });
		      stream._type = 'fs';
		      break;

		    case 'PIPE':
		    case 'TCP':
		      var net = require$$4$2;
		      stream = new net.Socket({
		        fd: fd,
		        readable: false,
		        writable: true
		      });

		      // FIXME Should probably have an option in net.Socket to create a
		      // stream from an existing fd which is writable only. But for now
		      // we'll just add this hack and set the `readable` member to false.
		      // Test: ./node test/fixtures/echo.js < /etc/passwd
		      stream.readable = false;
		      stream.read = null;
		      stream._type = 'pipe';

		      // FIXME Hack to have stream not keep the event loop alive.
		      // See https://github.com/joyent/node/issues/1726
		      if (stream._handle && stream._handle.unref) {
		        stream._handle.unref();
		      }
		      break;

		    default:
		      // Probably an error on in uv_guess_handle()
		      throw new Error('Implement me. Unknown stream file type!');
		  }

		  // For supporting legacy API we put the FD here.
		  stream.fd = fd;

		  stream._isStdio = true;

		  return stream;
		}
Get the specificity of the media type.
@private