Add stdin/stdout/stderr options to kernel launch functions.

IPython/zmq/entry_point.py

@@ -23,6 +23,7 b' from iostream import OutStream'
 from parentpoller import ParentPollerUnix, ParentPollerWindows
 from session import Session
 
+
 def bind_port(socket, ip, port):
     """ Binds the specified ZMQ socket. If the port is zero, a random port is
     chosen. Returns the port that was bound.
@@ -155,6 +156,7 b' def make_default_main(kernel_factory):'
 
 
 def base_launch_kernel(code, xrep_port=0, pub_port=0, req_port=0, hb_port=0,
+                       stdin=None, stdout=None, stderr=None,
                        executable=None, independent=False, extra_arguments=[]):
     """ Launches a localhost kernel, binding to the specified ports.
 
@@ -175,6 +177,9 b' def base_launch_kernel(code, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     hb_port : int, optional
         The port to use for the hearbeat REP channel.
 
+    stdin, stdout, stderr : optional (default None)
+        Standards streams, as defined in subprocess.Popen.
+
     executable : str, optional (default sys.executable)
         The Python executable to use for the kernel process.
 
@@ -231,12 +236,19 b' def base_launch_kernel(code, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
         # If using pythonw, stdin, stdout, and stderr are invalid. Popen will
         # fail unless they are suitably redirected. We don't read from the
         # pipes, but they must exist.
-        redirect = PIPE if executable.endswith('pythonw.exe') else None
+        if executable.endswith('pythonw.exe'):
+            redirect = True
+            _stdin = PIPE if stdin is None else stdin
+            _stdout = PIPE if stdout is None else stdout
+            _stderr = PIPE if stderr is None else stderr
+        else:
+            redirect = False
+            _stdin, _stdout, _stderr = stdin, stdout, stderr
 
         if independent:
             proc = Popen(arguments, 
                          creationflags=512, # CREATE_NEW_PROCESS_GROUP
-                         stdout=redirect, stderr=redirect, stdin=redirect)
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr)
         else:
             from _subprocess import DuplicateHandle, GetCurrentProcess, \
                 DUPLICATE_SAME_ACCESS
@@ -245,21 +257,26 b' def base_launch_kernel(code, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
                                      True, # Inheritable by new processes.
                                      DUPLICATE_SAME_ACCESS)
             proc = Popen(arguments + ['--parent', str(int(handle))],
-                         stdout=redirect, stderr=redirect, stdin=redirect)
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr)
 
         # Attach the interrupt event to the Popen objet so it can be used later.
         proc.win32_interrupt_event = interrupt_event
 
         # Clean up pipes created to work around Popen bug.
-        if redirect is not None:
+        if redirect:
+            if stdin is None:
+                proc.stdin.close()
+            if stdout is None:
             proc.stdout.close()
+            if stderr is None:
             proc.stderr.close()
-            proc.stdin.close()
 
     else:
         if independent:
-            proc = Popen(arguments, preexec_fn=lambda: os.setsid())
+            proc = Popen(arguments, preexec_fn=lambda: os.setsid(),
+                         stdin=stdin, stdout=stdout, stderr=stderr)
         else:
-            proc = Popen(arguments + ['--parent'])
+            proc = Popen(arguments + ['--parent'],
+                         stdin=stdin, stdout=stdout, stderr=stderr)
 
     return proc, xrep_port, pub_port, req_port, hb_port

IPython/zmq/ipkernel.py

@@ -551,6 +551,7 b' class GTKKernel(Kernel):'
 #-----------------------------------------------------------------------------
 
 def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,
+                  stdin=None, stdout=None, stderr=None,
                   executable=None, independent=False, pylab=False, colors=None):
     """Launches a localhost kernel, binding to the specified ports.
 
@@ -571,6 +572,9 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     hb_port : int, optional
         The port to use for the hearbeat REP channel.
 
+    stdin, stdout, stderr : optional (default None)
+        Standards streams, as defined in subprocess.Popen.
+
     executable : str, optional (default sys.executable)
         The Python executable to use for the kernel process.
 
@@ -608,6 +612,7 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
         extra_arguments.append(colors)
     return base_launch_kernel('from IPython.zmq.ipkernel import main; main()',
                               xrep_port, pub_port, req_port, hb_port, 
+                              stdin, stdout, stderr,
                               executable, independent, extra_arguments)
 
 

IPython/zmq/pykernel.py

@@ -248,6 +248,7 b' class Kernel(HasTraits):'
 #-----------------------------------------------------------------------------
 
 def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,
+                  stdin=None, stdout=None, stderr=None,
                   executable=None, independent=False):
     """ Launches a localhost kernel, binding to the specified ports.
 
@@ -268,6 +269,9 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     hb_port : int, optional
         The port to use for the hearbeat REP channel.
 
+    stdin, stdout, stderr : optional (default None)
+        Standards streams, as defined in subprocess.Popen.
+
     executable : str, optional (default sys.executable)
         The Python executable to use for the kernel process.
 
@@ -291,8 +295,8 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     
     return base_launch_kernel('from IPython.zmq.pykernel import main; main()',
                               xrep_port, pub_port, req_port, hb_port,
-                              executable, independent,
-                              extra_arguments=extra_arguments)
+                              stdin, stdout, stderr,
+                              executable, independent, extra_arguments)
 
 main = make_default_main(Kernel)