[termconsole] raw_input improvements

* allow EOF to be forwarded
* flush iopub in more appropriate places
* handle interrupting raw_input better

IPython/frontend/terminal/console/interactiveshell.py

@@ -1,311 +1,337 b''
 # -*- coding: utf-8 -*-
 """Frontend of ipython working with python-zmq
 
 Ipython's frontend, is a ipython interface that send request to kernel and proccess the kernel's outputs.
 
 For more details, see the ipython-zmq design
 """
 #-----------------------------------------------------------------------------
 # Copyright (C) 2011 The IPython Development Team
 #
 # Distributed under the terms of the BSD License. The full license is in
 # the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 import bdb
+import signal
 import sys
 import time
 
 from Queue import Empty
 
 from IPython.core.alias import AliasManager, AliasError
 from IPython.core import page
 from IPython.utils.warn import warn, error, fatal
 from IPython.utils import io
 
 from IPython.frontend.terminal.interactiveshell import TerminalInteractiveShell
 from IPython.frontend.terminal.console.completer import ZMQCompleter
 
 
 class ZMQTerminalInteractiveShell(TerminalInteractiveShell):
     """A subclass of TerminalInteractiveShell that uses the 0MQ kernel"""
     _executing = False
     
     def __init__(self, *args, **kwargs):
         self.km = kwargs.pop('kernel_manager')
         self.session_id = self.km.session.session
         super(ZMQTerminalInteractiveShell, self).__init__(*args, **kwargs)
         
     def init_completer(self):
         """Initialize the completion machinery.
 
         This creates completion machinery that can be used by client code,
         either interactively in-process (typically triggered by the readline
         library), programatically (such as in test suites) or out-of-prcess
         (typically over the network by remote frontends).
         """
         from IPython.core.completerlib import (module_completer,
                                                magic_run_completer, cd_completer)
         
         self.Completer = ZMQCompleter(self, self.km)
         
 
         self.set_hook('complete_command', module_completer, str_key = 'import')
         self.set_hook('complete_command', module_completer, str_key = 'from')
         self.set_hook('complete_command', magic_run_completer, str_key = '%run')
         self.set_hook('complete_command', cd_completer, str_key = '%cd')
 
         # Only configure readline if we truly are using readline.  IPython can
         # do tab-completion over the network, in GUIs, etc, where readline
         # itself may be absent
         if self.has_readline:
             self.set_readline_completer()
     
     def run_cell(self, cell, store_history=True):
         """Run a complete IPython cell.
         
         Parameters
         ----------
         cell : str
           The code (including IPython code such as %magic functions) to run.
         store_history : bool
           If True, the raw and translated cell will be stored in IPython's
           history. For user code calling back into IPython's machinery, this
           should be set to False.
         """
         if (not cell) or cell.isspace():
             return
 
         self._executing = True
         # flush stale replies, which could have been ignored, due to missed heartbeats
         while self.km.shell_channel.msg_ready():
             self.km.shell_channel.get_msg()
         # shell_channel.execute takes 'hidden', which is the inverse of store_hist
         msg_id = self.km.shell_channel.execute(cell, not store_history)
         while not self.km.shell_channel.msg_ready() and self.km.is_alive:
             try:
                 self.handle_stdin_request(timeout=0.05)
             except Empty:
                 # display intermediate print statements, etc.
                 self.handle_iopub()
                 pass
         if self.km.shell_channel.msg_ready():
             self.handle_execute_reply(msg_id)
         self._executing = False
 
     #-----------------
     # message handlers
     #-----------------
 
     def handle_execute_reply(self, msg_id):
         msg = self.km.shell_channel.get_msg()
         if msg["parent_header"].get("msg_id", None) == msg_id:
             
             self.handle_iopub()
             
             content = msg["content"]
             status = content['status']
             
             if status == 'aborted':
                 self.write('Aborted\n')
                 return
             elif status == 'ok':
                 # print execution payloads as well:
                 for item in content["payload"]:
                     text = item.get('text', None)
                     if text:
                         page.page(text)
                
             elif status == 'error':
                 for frame in content["traceback"]:
                     print(frame, file=io.stderr)
             
             self.execution_count = int(content["execution_count"] + 1)
 
 
     def handle_iopub(self):
         """ Method to procces subscribe channel's messages
 
            This method reads a message and processes the content in different
            outputs like stdout, stderr, pyout and status
 
            Arguments:
            sub_msg:  message receive from kernel in the sub socket channel
                      capture by kernel manager.
         """
         while self.km.sub_channel.msg_ready():
             sub_msg = self.km.sub_channel.get_msg()
             msg_type = sub_msg['header']['msg_type']
             if self.session_id == sub_msg['parent_header']['session']:
                 if msg_type == 'status' :
                     if sub_msg["content"]["execution_state"] == "busy" :
                         pass
 
                 elif msg_type == 'stream' :
                     if sub_msg["content"]["name"] == "stdout":
                         print(sub_msg["content"]["data"], file=io.stdout, end="")
                         io.stdout.flush()
                     elif sub_msg["content"]["name"] == "stderr" :
                         print(sub_msg["content"]["data"], file=io.stderr, end="")
                         io.stderr.flush()
 
                 elif msg_type == 'pyout':
                     self.execution_count = int(sub_msg["content"]["execution_count"])
                     format_dict = sub_msg["content"]["data"]
                     # taken from DisplayHook.__call__:
                     hook = self.displayhook
                     hook.start_displayhook()
                     hook.write_output_prompt()
                     hook.write_format_data(format_dict)
                     hook.log_output(format_dict)
                     hook.finish_displayhook()
 
     def handle_stdin_request(self, timeout=0.1):
         """ Method to capture raw_input
         """
         msg_rep = self.km.stdin_channel.get_msg(timeout=timeout)
+        # in case any iopub came while we were waiting:
+        self.handle_iopub()
         if self.session_id == msg_rep["parent_header"]["session"] :
+            # wrap SIGINT handler
+            real_handler = signal.getsignal(signal.SIGINT)
+            def double_int(sig,frame):
+                # call real handler (forwards sigint to kernel),
+                # then raise local interrupt, stopping local raw_input
+                real_handler(sig,frame)
+                raise KeyboardInterrupt
+            signal.signal(signal.SIGINT, double_int)
+            
+            try:
             raw_data = raw_input(msg_rep["content"]["prompt"])
+            except EOFError:
+                # turn EOFError into EOF character
+                raw_data = '\x04'
+            except KeyboardInterrupt:
+                sys.stdout.write('\n')
+                return
+            finally:
+                # restore SIGINT handler
+                signal.signal(signal.SIGINT, real_handler)
+            
+            # only send stdin reply if there *was not* another request
+            # or execution finished while we were reading.
+            if not (self.km.stdin_channel.msg_ready() or self.km.shell_channel.msg_ready()):
             self.km.stdin_channel.input(raw_data)
 
     def mainloop(self, display_banner=False):
         while True:
             try:
                 self.interact(display_banner=display_banner)
                 #self.interact_with_readline()                
                 # XXX for testing of a readline-decoupled repl loop, call
                 # interact_with_readline above
                 break
             except KeyboardInterrupt:
                 # this should not be necessary, but KeyboardInterrupt
                 # handling seems rather unpredictable...
                 self.write("\nKeyboardInterrupt in interact()\n")
     
     def wait_for_kernel(self, timeout=None):
         """method to wait for a kernel to be ready"""
         tic = time.time()
         self.km.hb_channel.unpause()
         while True:
             self.run_cell('1', False)
             if self.km.hb_channel.is_beating():
                 # heart failure was not the reason this returned
                 break
             else:
                 # heart failed
                 if timeout is not None and (time.time() - tic) > timeout:
                     return False
         return True
     
     def interact(self, display_banner=None):
         """Closely emulate the interactive Python console."""
 
         # batch run -> do not interact
         if self.exit_now:
             return
 
         if display_banner is None:
             display_banner = self.display_banner
         
         if isinstance(display_banner, basestring):
             self.show_banner(display_banner)
         elif display_banner:
             self.show_banner()
 
         more = False
         
         # run a non-empty no-op, so that we don't get a prompt until
         # we know the kernel is ready. This keeps the connection
         # message above the first prompt.
         if not self.wait_for_kernel(3):
             error("Kernel did not respond\n")
             return
         
         if self.has_readline:
             self.readline_startup_hook(self.pre_readline)
             hlen_b4_cell = self.readline.get_current_history_length()
         else:
             hlen_b4_cell = 0
         # exit_now is set by a call to %Exit or %Quit, through the
         # ask_exit callback.
 
         while not self.exit_now:
             if not self.km.is_alive:
                 # kernel died, prompt for action or exit
                 action = "restart" if self.km.has_kernel else "wait for restart"
                 ans = self.ask_yes_no("kernel died, %s ([y]/n)?" % action, default='y')
                 if ans:
                     if self.km.has_kernel:
                         self.km.restart_kernel(True)
                     self.wait_for_kernel(3)
                 else:
                     self.exit_now = True
                 continue
             try:
                 # protect prompt block from KeyboardInterrupt
                 # when sitting on ctrl-C
                 self.hooks.pre_prompt_hook()
                 if more:
                     try:
                         prompt = self.hooks.generate_prompt(True)
                     except Exception:
                         self.showtraceback()
                     if self.autoindent:
                         self.rl_do_indent = True
                     
                 else:
                     try:
                         prompt = self.hooks.generate_prompt(False)
                     except Exception:
                         self.showtraceback()
                 
                 line = self.raw_input(prompt)
                 if self.exit_now:
                     # quick exit on sys.std[in|out] close
                     break
                 if self.autoindent:
                     self.rl_do_indent = False
                     
             except KeyboardInterrupt:
                 #double-guard against keyboardinterrupts during kbdint handling
                 try:
                     self.write('\nKeyboardInterrupt\n')
                     source_raw = self.input_splitter.source_raw_reset()[1]
                     hlen_b4_cell = self._replace_rlhist_multiline(source_raw, hlen_b4_cell)
                     more = False
                 except KeyboardInterrupt:
                     pass
             except EOFError:
                 if self.autoindent:
                     self.rl_do_indent = False
                     if self.has_readline:
                         self.readline_startup_hook(None)
                 self.write('\n')
                 self.exit()
             except bdb.BdbQuit:
                 warn('The Python debugger has exited with a BdbQuit exception.\n'
                      'Because of how pdb handles the stack, it is impossible\n'
                      'for IPython to properly format this particular exception.\n'
                      'IPython will resume normal operation.')
             except:
                 # exceptions here are VERY RARE, but they can be triggered
                 # asynchronously by signal handlers, for example.
                 self.showtraceback()
             else:
                 self.input_splitter.push(line)
                 more = self.input_splitter.push_accepts_more()
                 if (self.SyntaxTB.last_syntax_error and
                     self.autoedit_syntax):
                     self.edit_syntax_error()
                 if not more:
                     source_raw = self.input_splitter.source_reset()
                     hlen_b4_cell = self._replace_rlhist_multiline(source_raw, hlen_b4_cell)
                     self.run_cell(source_raw)
                 
 
         # Turn off the exit flag, so the mainloop can be restarted if desired
         self.exit_now = False

IPython/zmq/ipkernel.py

@@ -1,648 +1,651 b''
 #!/usr/bin/env python
 """A simple interactive kernel that talks to a frontend over 0MQ.
 
 Things to do:
 
 * Implement `set_parent` logic. Right before doing exec, the Kernel should
   call set_parent on all the PUB objects with the message about to be executed.
 * Implement random port and security key logic.
 * Implement control messages.
 * Implement event loop and poll version.
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Standard library imports.
 import __builtin__
 import atexit
 import sys
 import time
 import traceback
 import logging
 from signal import (
         signal, default_int_handler, SIGINT, SIG_IGN
 )
 # System library imports.
 import zmq
 
 # Local imports.
 from IPython.core import pylabtools
 from IPython.config.configurable import Configurable
 from IPython.config.application import boolean_flag, catch_config_error
 from IPython.core.application import ProfileDir
 from IPython.core.error import StdinNotImplementedError
 from IPython.core.shellapp import (
     InteractiveShellApp, shell_flags, shell_aliases
 )
 from IPython.utils import io
 from IPython.utils import py3compat
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import (
     Any, Instance, Float, Dict, CaselessStrEnum
 )
 
 from entry_point import base_launch_kernel
 from kernelapp import KernelApp, kernel_flags, kernel_aliases
 from session import Session, Message
 from zmqshell import ZMQInteractiveShell
 
 
 #-----------------------------------------------------------------------------
 # Main kernel class
 #-----------------------------------------------------------------------------
 
 class Kernel(Configurable):
 
     #---------------------------------------------------------------------------
     # Kernel interface
     #---------------------------------------------------------------------------
 
     # attribute to override with a GUI
     eventloop = Any(None)
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
     session = Instance(Session)
     profile_dir = Instance('IPython.core.profiledir.ProfileDir')
     shell_socket = Instance('zmq.Socket')
     iopub_socket = Instance('zmq.Socket')
     stdin_socket = Instance('zmq.Socket')
     log = Instance(logging.Logger)
 
     # Private interface
 
     # Time to sleep after flushing the stdout/err buffers in each execute
     # cycle.  While this introduces a hard limit on the minimal latency of the
     # execute cycle, it helps prevent output synchronization problems for
     # clients.
     # Units are in seconds.  The minimum zmq latency on local host is probably
     # ~150 microseconds, set this to 500us for now.  We may need to increase it
     # a little if it's not enough after more interactive testing.
     _execute_sleep = Float(0.0005, config=True)
 
     # Frequency of the kernel's event loop.
     # Units are in seconds, kernel subclasses for GUI toolkits may need to
     # adapt to milliseconds.
     _poll_interval = Float(0.05, config=True)
 
     # If the shutdown was requested over the network, we leave here the
     # necessary reply message so it can be sent by our registered atexit
     # handler.  This ensures that the reply is only sent to clients truly at
     # the end of our shutdown process (which happens after the underlying
     # IPython shell's own shutdown).
     _shutdown_message = None
 
     # This is a dict of port number that the kernel is listening on. It is set
     # by record_ports and used by connect_request.
     _recorded_ports = Dict()
 
 
 
     def __init__(self, **kwargs):
         super(Kernel, self).__init__(**kwargs)
 
         # Before we even start up the shell, register *first* our exit handlers
         # so they come before the shell's
         atexit.register(self._at_shutdown)
 
         # Initialize the InteractiveShell subclass
         self.shell = ZMQInteractiveShell.instance(config=self.config,
             profile_dir = self.profile_dir,
         )
         self.shell.displayhook.session = self.session
         self.shell.displayhook.pub_socket = self.iopub_socket
         self.shell.display_pub.session = self.session
         self.shell.display_pub.pub_socket = self.iopub_socket
 
         # TMP - hack while developing
         self.shell._reply_content = None
 
         # Build dict of handlers for message types
         msg_types = [ 'execute_request', 'complete_request',
                       'object_info_request', 'history_request',
                       'connect_request', 'shutdown_request']
         self.handlers = {}
         for msg_type in msg_types:
             self.handlers[msg_type] = getattr(self, msg_type)
 
     def do_one_iteration(self):
         """Do one iteration of the kernel's evaluation loop.
         """
         try:
             ident,msg = self.session.recv(self.shell_socket, zmq.NOBLOCK)
         except Exception:
             self.log.warn("Invalid Message:", exc_info=True)
             return
         if msg is None:
             return
 
         msg_type = msg['header']['msg_type']
 
         # This assert will raise in versions of zeromq 2.0.7 and lesser.
         # We now require 2.0.8 or above, so we can uncomment for safety.
         # print(ident,msg, file=sys.__stdout__)
         assert ident is not None, "Missing message part."
 
         # Print some info about this message and leave a '--->' marker, so it's
         # easier to trace visually the message chain when debugging.  Each
         # handler prints its message at the end.
         self.log.debug('\n*** MESSAGE TYPE:'+str(msg_type)+'***')
         self.log.debug('   Content: '+str(msg['content'])+'\n   --->\n   ')
 
         # Find and call actual handler for message
         handler = self.handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN MESSAGE TYPE:" +str(msg))
         else:
             handler(ident, msg)
 
         # Check whether we should exit, in case the incoming message set the
         # exit flag on
         if self.shell.exit_now:
             self.log.debug('\nExiting IPython kernel...')
             # We do a normal, clean exit, which allows any actions registered
             # via atexit (such as history saving) to take place.
             sys.exit(0)
 
 
     def start(self):
         """ Start the kernel main loop.
         """
         # a KeyboardInterrupt (SIGINT) can occur on any python statement, so
         # let's ignore (SIG_IGN) them until we're in a place to handle them properly
         signal(SIGINT,SIG_IGN)
         poller = zmq.Poller()
         poller.register(self.shell_socket, zmq.POLLIN)
         # loop while self.eventloop has not been overridden
         while self.eventloop is None:
             try:
                 # scale by extra factor of 10, because there is no
                 # reason for this to be anything less than ~ 0.1s
                 # since it is a real poller and will respond
                 # to events immediately
 
                 # double nested try/except, to properly catch KeyboardInterrupt
                 # due to pyzmq Issue #130
                 try:
                     poller.poll(10*1000*self._poll_interval)
                     # restore raising of KeyboardInterrupt
                     signal(SIGINT, default_int_handler)
                     self.do_one_iteration()
                 except:
                     raise
                 finally:
                     # prevent raising of KeyboardInterrupt
                     signal(SIGINT,SIG_IGN)
             except KeyboardInterrupt:
                 # Ctrl-C shouldn't crash the kernel
                 io.raw_print("KeyboardInterrupt caught in kernel")
         # stop ignoring sigint, now that we are out of our own loop,
         # we don't want to prevent future code from handling it
         signal(SIGINT, default_int_handler)
         if self.eventloop is not None:
             try:
                 self.eventloop(self)
             except KeyboardInterrupt:
                 # Ctrl-C shouldn't crash the kernel
                 io.raw_print("KeyboardInterrupt caught in kernel")
 
 
     def record_ports(self, ports):
         """Record the ports that this kernel is using.
 
         The creator of the Kernel instance must call this methods if they
         want the :meth:`connect_request` method to return the port numbers.
         """
         self._recorded_ports = ports
 
     #---------------------------------------------------------------------------
     # Kernel request handlers
     #---------------------------------------------------------------------------
 
     def _publish_pyin(self, code, parent):
         """Publish the code request on the pyin stream."""
 
         self.session.send(self.iopub_socket, u'pyin', {u'code':code},
                           parent=parent)
 
     def execute_request(self, ident, parent):
 
         self.session.send(self.iopub_socket,
                           u'status',
                           {u'execution_state':u'busy'},
                           parent=parent )
         
         try:
             content = parent[u'content']
             code = content[u'code']
             silent = content[u'silent']
         except:
             self.log.error("Got bad msg: ")
             self.log.error(str(Message(parent)))
             return
 
         shell = self.shell # we'll need this a lot here
 
         # Replace raw_input. Note that is not sufficient to replace
         # raw_input in the user namespace.
         if content.get('allow_stdin', False):
             raw_input = lambda prompt='': self._raw_input(prompt, ident, parent)
         else:
             raw_input = lambda prompt='' : self._no_raw_input()
 
         if py3compat.PY3:
             __builtin__.input = raw_input
         else:
             __builtin__.raw_input = raw_input
 
         # Set the parent message of the display hook and out streams.
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         sys.stdout.set_parent(parent)
         sys.stderr.set_parent(parent)
 
         # Re-broadcast our input for the benefit of listening clients, and
         # start computing output
         if not silent:
             self._publish_pyin(code, parent)
 
         reply_content = {}
         try:
             if silent:
                 # run_code uses 'exec' mode, so no displayhook will fire, and it
                 # doesn't call logging or history manipulations.  Print
                 # statements in that code will obviously still execute.
                 shell.run_code(code)
             else:
                 # FIXME: the shell calls the exception handler itself.
                 shell.run_cell(code, store_history=True)
         except:
             status = u'error'
             # FIXME: this code right now isn't being used yet by default,
             # because the run_cell() call above directly fires off exception
             # reporting.  This code, therefore, is only active in the scenario
             # where runlines itself has an unhandled exception.  We need to
             # uniformize this, for all exception construction to come from a
             # single location in the codbase.
             etype, evalue, tb = sys.exc_info()
             tb_list = traceback.format_exception(etype, evalue, tb)
             reply_content.update(shell._showtraceback(etype, evalue, tb_list))
         else:
             status = u'ok'
 
         reply_content[u'status'] = status
 
         # Return the execution counter so clients can display prompts
         reply_content['execution_count'] = shell.execution_count -1
 
         # FIXME - fish exception info out of shell, possibly left there by
         # runlines.  We'll need to clean up this logic later.
         if shell._reply_content is not None:
             reply_content.update(shell._reply_content)
             # reset after use
             shell._reply_content = None
 
         # At this point, we can tell whether the main code execution succeeded
         # or not.  If it did, we proceed to evaluate user_variables/expressions
         if reply_content['status'] == 'ok':
             reply_content[u'user_variables'] = \
                          shell.user_variables(content[u'user_variables'])
             reply_content[u'user_expressions'] = \
                          shell.user_expressions(content[u'user_expressions'])
         else:
             # If there was an error, don't even try to compute variables or
             # expressions
             reply_content[u'user_variables'] = {}
             reply_content[u'user_expressions'] = {}
 
         # Payloads should be retrieved regardless of outcome, so we can both
         # recover partial output (that could have been generated early in a
         # block, before an error) and clear the payload system always.
         reply_content[u'payload'] = shell.payload_manager.read_payload()
         # Be agressive about clearing the payload because we don't want
         # it to sit in memory until the next execute_request comes in.
         shell.payload_manager.clear_payload()
 
         # Flush output before sending the reply.
         sys.stdout.flush()
         sys.stderr.flush()
         # FIXME: on rare occasions, the flush doesn't seem to make it to the
         # clients... This seems to mitigate the problem, but we definitely need
         # to better understand what's going on.
         if self._execute_sleep:
             time.sleep(self._execute_sleep)
 
         # Send the reply.
         reply_content = json_clean(reply_content)
         reply_msg = self.session.send(self.shell_socket, u'execute_reply',
                                       reply_content, parent, ident=ident)
         self.log.debug(str(reply_msg))
 
         if reply_msg['content']['status'] == u'error':
             self._abort_queue()
 
         self.session.send(self.iopub_socket,
                           u'status',
                           {u'execution_state':u'idle'},
                           parent=parent )
 
     def complete_request(self, ident, parent):
         txt, matches = self._complete(parent)
         matches = {'matches' : matches,
                    'matched_text' : txt,
                    'status' : 'ok'}
         matches = json_clean(matches)
         completion_msg = self.session.send(self.shell_socket, 'complete_reply',
                                            matches, parent, ident)
         self.log.debug(str(completion_msg))
 
     def object_info_request(self, ident, parent):
         object_info = self.shell.object_inspect(parent['content']['oname'])
         # Before we send this object over, we scrub it for JSON usage
         oinfo = json_clean(object_info)
         msg = self.session.send(self.shell_socket, 'object_info_reply',
                                 oinfo, parent, ident)
         self.log.debug(msg)
 
     def history_request(self, ident, parent):
         # We need to pull these out, as passing **kwargs doesn't work with
         # unicode keys before Python 2.6.5.
         hist_access_type = parent['content']['hist_access_type']
         raw = parent['content']['raw']
         output = parent['content']['output']
         if hist_access_type == 'tail':
             n = parent['content']['n']
             hist = self.shell.history_manager.get_tail(n, raw=raw, output=output,
                                                             include_latest=True)
 
         elif hist_access_type == 'range':
             session = parent['content']['session']
             start = parent['content']['start']
             stop = parent['content']['stop']
             hist = self.shell.history_manager.get_range(session, start, stop,
                                                         raw=raw, output=output)
 
         elif hist_access_type == 'search':
             pattern = parent['content']['pattern']
             hist = self.shell.history_manager.search(pattern, raw=raw,
                                                      output=output) 
 
         else:
             hist = []
         content = {'history' : list(hist)}
         content = json_clean(content)
         msg = self.session.send(self.shell_socket, 'history_reply',
                                 content, parent, ident)
         self.log.debug(str(msg))
 
     def connect_request(self, ident, parent):
         if self._recorded_ports is not None:
             content = self._recorded_ports.copy()
         else:
             content = {}
         msg = self.session.send(self.shell_socket, 'connect_reply',
                                 content, parent, ident)
         self.log.debug(msg)
 
     def shutdown_request(self, ident, parent):
         self.shell.exit_now = True
         self._shutdown_message = self.session.msg(u'shutdown_reply',
                                                   parent['content'], parent)
         sys.exit(0)
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
 
     def _abort_queue(self):
         while True:
             try:
                 ident,msg = self.session.recv(self.shell_socket, zmq.NOBLOCK)
             except Exception:
                 self.log.warn("Invalid Message:", exc_info=True)
                 continue
             if msg is None:
                 break
             else:
                 assert ident is not None, \
                        "Unexpected missing message part."
 
             self.log.debug("Aborting:\n"+str(Message(msg)))
             msg_type = msg['header']['msg_type']
             reply_type = msg_type.split('_')[0] + '_reply'
             reply_msg = self.session.send(self.shell_socket, reply_type,
                     {'status' : 'aborted'}, msg, ident=ident)
             self.log.debug(reply_msg)
             # We need to wait a bit for requests to come in. This can probably
             # be set shorter for true asynchronous clients.
             time.sleep(0.1)
 
     def _no_raw_input(self):
         """Raise StdinNotImplentedError if active frontend doesn't support
         stdin."""
         raise StdinNotImplementedError("raw_input was called, but this "
                                        "frontend does not support stdin.") 
         
     def _raw_input(self, prompt, ident, parent):
         # Flush output before making the request.
         sys.stderr.flush()
         sys.stdout.flush()
 
         # Send the input request.
         content = json_clean(dict(prompt=prompt))
         self.session.send(self.stdin_socket, u'input_request', content, parent,
                           ident=ident)
 
         # Await a response.
         while True:
             try:
                 ident, reply = self.session.recv(self.stdin_socket, 0)
             except Exception:
                 self.log.warn("Invalid Message:", exc_info=True)
             else:
                 break
         try:
             value = reply['content']['value']
         except:
             self.log.error("Got bad raw_input reply: ")
             self.log.error(str(Message(parent)))
             value = ''
+        if value == '\x04':
+            # EOF
+            raise EOFError
         return value
 
     def _complete(self, msg):
         c = msg['content']
         try:
             cpos = int(c['cursor_pos'])
         except:
             # If we don't get something that we can convert to an integer, at
             # least attempt the completion guessing the cursor is at the end of
             # the text, if there's any, and otherwise of the line
             cpos = len(c['text'])
             if cpos==0:
                 cpos = len(c['line'])
         return self.shell.complete(c['text'], c['line'], cpos)
 
     def _object_info(self, context):
         symbol, leftover = self._symbol_from_context(context)
         if symbol is not None and not leftover:
             doc = getattr(symbol, '__doc__', '')
         else:
             doc = ''
         object_info = dict(docstring = doc)
         return object_info
 
     def _symbol_from_context(self, context):
         if not context:
             return None, context
 
         base_symbol_string = context[0]
         symbol = self.shell.user_ns.get(base_symbol_string, None)
         if symbol is None:
             symbol = __builtin__.__dict__.get(base_symbol_string, None)
         if symbol is None:
             return None, context
 
         context = context[1:]
         for i, name in enumerate(context):
             new_symbol = getattr(symbol, name, None)
             if new_symbol is None:
                 return symbol, context[i:]
             else:
                 symbol = new_symbol
 
         return symbol, []
 
     def _at_shutdown(self):
         """Actions taken at shutdown by the kernel, called by python's atexit.
         """
         # io.rprint("Kernel at_shutdown") # dbg
         if self._shutdown_message is not None:
             self.session.send(self.shell_socket, self._shutdown_message)
             self.session.send(self.iopub_socket, self._shutdown_message)
             self.log.debug(str(self._shutdown_message))
             # A very short sleep to give zmq time to flush its message buffers
             # before Python truly shuts down.
             time.sleep(0.01)
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags for the IPKernelApp
 #-----------------------------------------------------------------------------
 
 flags = dict(kernel_flags)
 flags.update(shell_flags)
 
 addflag = lambda *args: flags.update(boolean_flag(*args))
 
 flags['pylab'] = (
     {'IPKernelApp' : {'pylab' : 'auto'}},
     """Pre-load matplotlib and numpy for interactive use with
     the default matplotlib backend."""
 )
 
 aliases = dict(kernel_aliases)
 aliases.update(shell_aliases)
 
 # it's possible we don't want short aliases for *all* of these:
 aliases.update(dict(
     pylab='IPKernelApp.pylab',
 ))
 
 #-----------------------------------------------------------------------------
 # The IPKernelApp class
 #-----------------------------------------------------------------------------
 
 class IPKernelApp(KernelApp, InteractiveShellApp):
     name = 'ipkernel'
 
     aliases = Dict(aliases)
     flags = Dict(flags)
     classes = [Kernel, ZMQInteractiveShell, ProfileDir, Session]
     # configurables
     pylab = CaselessStrEnum(['tk', 'qt', 'wx', 'gtk', 'osx', 'inline', 'auto'],
         config=True,
         help="""Pre-load matplotlib and numpy for interactive use,
         selecting a particular matplotlib backend and loop integration.
         """
     )
     
     @catch_config_error
     def initialize(self, argv=None):
         super(IPKernelApp, self).initialize(argv)
         self.init_shell()
         self.init_extensions()
         self.init_code()
 
     def init_kernel(self):
 
         kernel = Kernel(config=self.config, session=self.session,
                                 shell_socket=self.shell_socket,
                                 iopub_socket=self.iopub_socket,
                                 stdin_socket=self.stdin_socket,
                                 log=self.log,
                                 profile_dir=self.profile_dir,
         )
         self.kernel = kernel
         kernel.record_ports(self.ports)
         shell = kernel.shell
         if self.pylab:
             try:
                 gui, backend = pylabtools.find_gui_and_backend(self.pylab)
                 shell.enable_pylab(gui, import_all=self.pylab_import_all)
             except Exception:
                 self.log.error("Pylab initialization failed", exc_info=True)
                 # print exception straight to stdout, because normally 
                 # _showtraceback associates the reply with an execution, 
                 # which means frontends will never draw it, as this exception 
                 # is not associated with any execute request.
                 
                 # replace pyerr-sending traceback with stdout
                 _showtraceback = shell._showtraceback
                 def print_tb(etype, evalue, stb):
                     print ("Error initializing pylab, pylab mode will not "
                            "be active", file=io.stderr)
                     print (shell.InteractiveTB.stb2text(stb), file=io.stdout)
                 shell._showtraceback = print_tb
                 
                 # send the traceback over stdout
                 shell.showtraceback(tb_offset=0)
                 
                 # restore proper _showtraceback method
                 shell._showtraceback = _showtraceback
                 
 
     def init_shell(self):
         self.shell = self.kernel.shell
         self.shell.configurables.append(self)
 
 
 #-----------------------------------------------------------------------------
 # Kernel main and launch functions
 #-----------------------------------------------------------------------------
 
 def launch_kernel(*args, **kwargs):
     """Launches a localhost IPython kernel, binding to the specified ports.
 
     This function simply calls entry_point.base_launch_kernel with the right
     first command to start an ipkernel.  See base_launch_kernel for arguments.
 
     Returns
     -------
     A tuple of form:
         (kernel_process, shell_port, iopub_port, stdin_port, hb_port)
     where kernel_process is a Popen object and the ports are integers.
     """
     return base_launch_kernel('from IPython.zmq.ipkernel import main; main()',
                               *args, **kwargs)
 
 
 def main():
     """Run an IPKernel as an application"""
     app = IPKernelApp.instance()
     app.initialize()
     app.start()
 
 
 if __name__ == '__main__':
     main()