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Use default OS shell to run system commands...
Use default OS shell to run system commands Instead of using os.system which uses /bin/sh, this uses subprocess.call (the replacement of os.system) to run the command using the default shell of the OS. With this, one can use more advanced commands for bash, zsh, ksh, ... I also edited the docstring, added comments and fixed the handling of return codes.

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ipkernel.py
806 lines | 30.3 KiB | text/x-python | PythonLexer
#!/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 sys
import time
import traceback
import logging
import uuid
from datetime import datetime
from signal import (
signal, default_int_handler, SIGINT
)
# System library imports
import zmq
from zmq.eventloop import ioloop
from zmq.eventloop.zmqstream import ZMQStream
# Local imports
from IPython.config.configurable import Configurable
from IPython.core.error import StdinNotImplementedError
from IPython.core import release
from IPython.utils import py3compat
from IPython.utils.jsonutil import json_clean
from IPython.utils.traitlets import (
Any, Instance, Float, Dict, List, Set, Integer, Unicode,
Type
)
from serialize import serialize_object, unpack_apply_message
from session import Session
from zmqshell import ZMQInteractiveShell
#-----------------------------------------------------------------------------
# Main kernel class
#-----------------------------------------------------------------------------
protocol_version = list(release.kernel_protocol_version_info)
ipython_version = list(release.version_info)
language_version = list(sys.version_info[:3])
class Kernel(Configurable):
#---------------------------------------------------------------------------
# Kernel interface
#---------------------------------------------------------------------------
# attribute to override with a GUI
eventloop = Any(None)
def _eventloop_changed(self, name, old, new):
"""schedule call to eventloop from IOLoop"""
loop = ioloop.IOLoop.instance()
loop.add_timeout(time.time()+0.1, self.enter_eventloop)
shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
shell_class = Type(ZMQInteractiveShell)
session = Instance(Session)
profile_dir = Instance('IPython.core.profiledir.ProfileDir')
shell_streams = List()
control_stream = Instance(ZMQStream)
iopub_socket = Instance(zmq.Socket)
stdin_socket = Instance(zmq.Socket)
log = Instance(logging.Logger)
user_module = Any()
def _user_module_changed(self, name, old, new):
if self.shell is not None:
self.shell.user_module = new
user_ns = Dict(default_value=None)
def _user_ns_changed(self, name, old, new):
if self.shell is not None:
self.shell.user_ns = new
self.shell.init_user_ns()
# identities:
int_id = Integer(-1)
ident = Unicode()
def _ident_default(self):
return unicode(uuid.uuid4())
# 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()
# A reference to the Python builtin 'raw_input' function.
# (i.e., __builtin__.raw_input for Python 2.7, builtins.input for Python 3)
_sys_raw_input = Any()
# set of aborted msg_ids
aborted = Set()
def __init__(self, **kwargs):
super(Kernel, self).__init__(**kwargs)
# Initialize the InteractiveShell subclass
self.shell = self.shell_class.instance(parent=self,
profile_dir = self.profile_dir,
user_module = self.user_module,
user_ns = self.user_ns,
)
self.shell.displayhook.session = self.session
self.shell.displayhook.pub_socket = self.iopub_socket
self.shell.displayhook.topic = self._topic('pyout')
self.shell.display_pub.session = self.session
self.shell.display_pub.pub_socket = self.iopub_socket
self.shell.data_pub.session = self.session
self.shell.data_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',
'kernel_info_request',
'connect_request', 'shutdown_request',
'apply_request',
]
self.shell_handlers = {}
for msg_type in msg_types:
self.shell_handlers[msg_type] = getattr(self, msg_type)
control_msg_types = msg_types + [ 'clear_request', 'abort_request' ]
self.control_handlers = {}
for msg_type in control_msg_types:
self.control_handlers[msg_type] = getattr(self, msg_type)
def dispatch_control(self, msg):
"""dispatch control requests"""
idents,msg = self.session.feed_identities(msg, copy=False)
try:
msg = self.session.unserialize(msg, content=True, copy=False)
except:
self.log.error("Invalid Control Message", exc_info=True)
return
self.log.debug("Control received: %s", msg)
header = msg['header']
msg_id = header['msg_id']
msg_type = header['msg_type']
handler = self.control_handlers.get(msg_type, None)
if handler is None:
self.log.error("UNKNOWN CONTROL MESSAGE TYPE: %r", msg_type)
else:
try:
handler(self.control_stream, idents, msg)
except Exception:
self.log.error("Exception in control handler:", exc_info=True)
def dispatch_shell(self, stream, msg):
"""dispatch shell requests"""
# flush control requests first
if self.control_stream:
self.control_stream.flush()
idents,msg = self.session.feed_identities(msg, copy=False)
try:
msg = self.session.unserialize(msg, content=True, copy=False)
except:
self.log.error("Invalid Message", exc_info=True)
return
header = msg['header']
msg_id = header['msg_id']
msg_type = msg['header']['msg_type']
# 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:%s***', msg_type)
self.log.debug(' Content: %s\n --->\n ', msg['content'])
if msg_id in self.aborted:
self.aborted.remove(msg_id)
# is it safe to assume a msg_id will not be resubmitted?
reply_type = msg_type.split('_')[0] + '_reply'
status = {'status' : 'aborted'}
md = {'engine' : self.ident}
md.update(status)
reply_msg = self.session.send(stream, reply_type, metadata=md,
content=status, parent=msg, ident=idents)
return
handler = self.shell_handlers.get(msg_type, None)
if handler is None:
self.log.error("UNKNOWN MESSAGE TYPE: %r", msg_type)
else:
# ensure default_int_handler during handler call
sig = signal(SIGINT, default_int_handler)
try:
handler(stream, idents, msg)
except Exception:
self.log.error("Exception in message handler:", exc_info=True)
finally:
signal(SIGINT, sig)
def enter_eventloop(self):
"""enter eventloop"""
self.log.info("entering eventloop")
# restore default_int_handler
signal(SIGINT, default_int_handler)
while self.eventloop is not None:
try:
self.eventloop(self)
except KeyboardInterrupt:
# Ctrl-C shouldn't crash the kernel
self.log.error("KeyboardInterrupt caught in kernel")
continue
else:
# eventloop exited cleanly, this means we should stop (right?)
self.eventloop = None
break
self.log.info("exiting eventloop")
def start(self):
"""register dispatchers for streams"""
self.shell.exit_now = False
if self.control_stream:
self.control_stream.on_recv(self.dispatch_control, copy=False)
def make_dispatcher(stream):
def dispatcher(msg):
return self.dispatch_shell(stream, msg)
return dispatcher
for s in self.shell_streams:
s.on_recv(make_dispatcher(s), copy=False)
# publish idle status
self._publish_status('starting')
def do_one_iteration(self):
"""step eventloop just once"""
if self.control_stream:
self.control_stream.flush()
for stream in self.shell_streams:
# handle at most one request per iteration
stream.flush(zmq.POLLIN, 1)
stream.flush(zmq.POLLOUT)
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 _make_metadata(self, other=None):
"""init metadata dict, for execute/apply_reply"""
new_md = {
'dependencies_met' : True,
'engine' : self.ident,
'started': datetime.now(),
}
if other:
new_md.update(other)
return new_md
def _publish_pyin(self, code, parent, execution_count):
"""Publish the code request on the pyin stream."""
self.session.send(self.iopub_socket, u'pyin',
{u'code':code, u'execution_count': execution_count},
parent=parent, ident=self._topic('pyin')
)
def _publish_status(self, status, parent=None):
"""send status (busy/idle) on IOPub"""
self.session.send(self.iopub_socket,
u'status',
{u'execution_state': status},
parent=parent,
ident=self._topic('status'),
)
def execute_request(self, stream, ident, parent):
"""handle an execute_request"""
self._publish_status(u'busy', parent)
try:
content = parent[u'content']
code = content[u'code']
silent = content[u'silent']
store_history = content.get(u'store_history', not silent)
except:
self.log.error("Got bad msg: ")
self.log.error("%s", parent)
return
md = self._make_metadata(parent['metadata'])
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:
self._sys_raw_input = __builtin__.input
__builtin__.input = raw_input
else:
self._sys_raw_input = __builtin__.raw_input
__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)
shell.data_pub.set_parent(parent)
try:
sys.stdout.set_parent(parent)
except AttributeError:
pass
try:
sys.stderr.set_parent(parent)
except AttributeError:
pass
# Re-broadcast our input for the benefit of listening clients, and
# start computing output
if not silent:
self._publish_pyin(code, parent, shell.execution_count)
reply_content = {}
try:
# FIXME: the shell calls the exception handler itself.
shell.run_cell(code, store_history=store_history, silent=silent)
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'
finally:
# Restore raw_input.
if py3compat.PY3:
__builtin__.input = self._sys_raw_input
else:
__builtin__.raw_input = self._sys_raw_input
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)
e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='execute')
reply_content['engine_info'] = e_info
# reset after use
shell._reply_content = None
if 'traceback' in reply_content:
self.log.info("Exception in execute request:\n%s", '\n'.join(reply_content['traceback']))
# 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.get(u'user_variables', []))
reply_content[u'user_expressions'] = \
shell.user_expressions(content.get(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)
md['status'] = reply_content['status']
if reply_content['status'] == 'error' and \
reply_content['ename'] == 'UnmetDependency':
md['dependencies_met'] = False
reply_msg = self.session.send(stream, u'execute_reply',
reply_content, parent, metadata=md,
ident=ident)
self.log.debug("%s", reply_msg)
if not silent and reply_msg['content']['status'] == u'error':
self._abort_queues()
self._publish_status(u'idle', parent)
def complete_request(self, stream, ident, parent):
txt, matches = self._complete(parent)
matches = {'matches' : matches,
'matched_text' : txt,
'status' : 'ok'}
matches = json_clean(matches)
completion_msg = self.session.send(stream, 'complete_reply',
matches, parent, ident)
self.log.debug("%s", completion_msg)
def object_info_request(self, stream, ident, parent):
content = parent['content']
object_info = self.shell.object_inspect(content['oname'],
detail_level = content.get('detail_level', 0)
)
# Before we send this object over, we scrub it for JSON usage
oinfo = json_clean(object_info)
msg = self.session.send(stream, 'object_info_reply',
oinfo, parent, ident)
self.log.debug("%s", msg)
def history_request(self, stream, 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':
n = parent['content'].get('n')
unique = parent['content'].get('unique', False)
pattern = parent['content']['pattern']
hist = self.shell.history_manager.search(
pattern, raw=raw, output=output, n=n, unique=unique)
else:
hist = []
hist = list(hist)
content = {'history' : hist}
content = json_clean(content)
msg = self.session.send(stream, 'history_reply',
content, parent, ident)
self.log.debug("Sending history reply with %i entries", len(hist))
def connect_request(self, stream, ident, parent):
if self._recorded_ports is not None:
content = self._recorded_ports.copy()
else:
content = {}
msg = self.session.send(stream, 'connect_reply',
content, parent, ident)
self.log.debug("%s", msg)
def kernel_info_request(self, stream, ident, parent):
vinfo = {
'protocol_version': protocol_version,
'ipython_version': ipython_version,
'language_version': language_version,
'language': 'python',
}
msg = self.session.send(stream, 'kernel_info_reply',
vinfo, parent, ident)
self.log.debug("%s", msg)
def shutdown_request(self, stream, ident, parent):
self.shell.exit_now = True
content = dict(status='ok')
content.update(parent['content'])
self.session.send(stream, u'shutdown_reply', content, parent, ident=ident)
# same content, but different msg_id for broadcasting on IOPub
self._shutdown_message = self.session.msg(u'shutdown_reply',
content, parent
)
self._at_shutdown()
# call sys.exit after a short delay
loop = ioloop.IOLoop.instance()
loop.add_timeout(time.time()+0.1, loop.stop)
#---------------------------------------------------------------------------
# Engine methods
#---------------------------------------------------------------------------
def apply_request(self, stream, ident, parent):
try:
content = parent[u'content']
bufs = parent[u'buffers']
msg_id = parent['header']['msg_id']
except:
self.log.error("Got bad msg: %s", parent, exc_info=True)
return
self._publish_status(u'busy', parent)
# Set the parent message of the display hook and out streams.
shell = self.shell
shell.displayhook.set_parent(parent)
shell.display_pub.set_parent(parent)
shell.data_pub.set_parent(parent)
try:
sys.stdout.set_parent(parent)
except AttributeError:
pass
try:
sys.stderr.set_parent(parent)
except AttributeError:
pass
# pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
# self.iopub_socket.send(pyin_msg)
# self.session.send(self.iopub_socket, u'pyin', {u'code':code},parent=parent)
md = self._make_metadata(parent['metadata'])
try:
working = shell.user_ns
prefix = "_"+str(msg_id).replace("-","")+"_"
f,args,kwargs = unpack_apply_message(bufs, working, copy=False)
fname = getattr(f, '__name__', 'f')
fname = prefix+"f"
argname = prefix+"args"
kwargname = prefix+"kwargs"
resultname = prefix+"result"
ns = { fname : f, argname : args, kwargname : kwargs , resultname : None }
# print ns
working.update(ns)
code = "%s = %s(*%s,**%s)" % (resultname, fname, argname, kwargname)
try:
exec code in shell.user_global_ns, shell.user_ns
result = working.get(resultname)
finally:
for key in ns.iterkeys():
working.pop(key)
result_buf = serialize_object(result,
buffer_threshold=self.session.buffer_threshold,
item_threshold=self.session.item_threshold,
)
except:
# invoke IPython traceback formatting
shell.showtraceback()
# FIXME - fish exception info out of shell, possibly left there by
# run_code. We'll need to clean up this logic later.
reply_content = {}
if shell._reply_content is not None:
reply_content.update(shell._reply_content)
e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='apply')
reply_content['engine_info'] = e_info
# reset after use
shell._reply_content = None
self.session.send(self.iopub_socket, u'pyerr', reply_content, parent=parent,
ident=self._topic('pyerr'))
self.log.info("Exception in apply request:\n%s", '\n'.join(reply_content['traceback']))
result_buf = []
if reply_content['ename'] == 'UnmetDependency':
md['dependencies_met'] = False
else:
reply_content = {'status' : 'ok'}
# put 'ok'/'error' status in header, for scheduler introspection:
md['status'] = reply_content['status']
# flush i/o
sys.stdout.flush()
sys.stderr.flush()
reply_msg = self.session.send(stream, u'apply_reply', reply_content,
parent=parent, ident=ident,buffers=result_buf, metadata=md)
self._publish_status(u'idle', parent)
#---------------------------------------------------------------------------
# Control messages
#---------------------------------------------------------------------------
def abort_request(self, stream, ident, parent):
"""abort a specifig msg by id"""
msg_ids = parent['content'].get('msg_ids', None)
if isinstance(msg_ids, basestring):
msg_ids = [msg_ids]
if not msg_ids:
self.abort_queues()
for mid in msg_ids:
self.aborted.add(str(mid))
content = dict(status='ok')
reply_msg = self.session.send(stream, 'abort_reply', content=content,
parent=parent, ident=ident)
self.log.debug("%s", reply_msg)
def clear_request(self, stream, idents, parent):
"""Clear our namespace."""
self.shell.reset(False)
msg = self.session.send(stream, 'clear_reply', ident=idents, parent=parent,
content = dict(status='ok'))
#---------------------------------------------------------------------------
# Protected interface
#---------------------------------------------------------------------------
def _wrap_exception(self, method=None):
# import here, because _wrap_exception is only used in parallel,
# and parallel has higher min pyzmq version
from IPython.parallel.error import wrap_exception
e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method=method)
content = wrap_exception(e_info)
return content
def _topic(self, topic):
"""prefixed topic for IOPub messages"""
if self.int_id >= 0:
base = "engine.%i" % self.int_id
else:
base = "kernel.%s" % self.ident
return py3compat.cast_bytes("%s.%s" % (base, topic))
def _abort_queues(self):
for stream in self.shell_streams:
if stream:
self._abort_queue(stream)
def _abort_queue(self, stream):
poller = zmq.Poller()
poller.register(stream.socket, zmq.POLLIN)
while True:
idents,msg = self.session.recv(stream, zmq.NOBLOCK, content=True)
if msg is None:
return
self.log.info("Aborting:")
self.log.info("%s", msg)
msg_type = msg['header']['msg_type']
reply_type = msg_type.split('_')[0] + '_reply'
status = {'status' : 'aborted'}
md = {'engine' : self.ident}
md.update(status)
reply_msg = self.session.send(stream, reply_type, metadata=md,
content=status, parent=msg, ident=idents)
self.log.debug("%s", reply_msg)
# We need to wait a bit for requests to come in. This can probably
# be set shorter for true asynchronous clients.
poller.poll(50)
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()
# flush the stdin socket, to purge stale replies
while True:
try:
self.stdin_socket.recv_multipart(zmq.NOBLOCK)
except zmq.ZMQError as e:
if e.errno == zmq.EAGAIN:
break
else:
raise
# 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)
except KeyboardInterrupt:
# re-raise KeyboardInterrupt, to truncate traceback
raise KeyboardInterrupt
else:
break
try:
value = py3compat.unicode_to_str(reply['content']['value'])
except:
self.log.error("Got bad raw_input reply: ")
self.log.error("%s", 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 _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.iopub_socket, self._shutdown_message, ident=self._topic('shutdown'))
self.log.debug("%s", self._shutdown_message)
[ s.flush(zmq.POLLOUT) for s in self.shell_streams ]