From 2971b6fc77d10394d024575aaeee26ce37699896 2008-07-26 00:59:36
From: Gael Varoquaux <gael.varoquaux@normalesup.org>
Date: 2008-07-26 00:59:36
Subject: [PATCH] Modified OutputTrap to accept a file-like object and use it instead of
SyncOutputTrap.

---

diff --git a/IPython/frontend/prefilterfrontend.py b/IPython/frontend/prefilterfrontend.py
index feda2c9..45532d4 100644
--- a/IPython/frontend/prefilterfrontend.py
+++ b/IPython/frontend/prefilterfrontend.py
@@ -21,7 +21,8 @@ from linefrontendbase import LineFrontEndBase, common_prefix
 
 from IPython.ipmaker import make_IPython
 from IPython.ipapi import IPApi
-from IPython.kernel.core.sync_output_trap import SyncOutputTrap
+from IPython.kernel.core.file_like import FileLike
+from IPython.kernel.core.output_trap import OutputTrap
 
 from IPython.genutils import Term
 import pydoc
@@ -33,13 +34,10 @@ import os
 def xterm_system(command):
     """ Run a command in a separate console window.
     """
-    os.system("""
-    xterm -title "%s" -e \'/bin/sh -c "%s ; 
-    printf \\"\\\\n\\"; 
-    printf \\"press a key to close\\" ; 
-    printf \\"\x1b]0;%s (finished -- press a key to close)\x07\\" ;
-    read foo;"\'
-    """  % (command, command, command) )
+    os.system(("""xterm -title "%s" -e \'/bin/sh -c "%s ; """
+               """echo; echo press enter to close ; """
+#               """echo \\"\x1b]0;%s (finished -- press enter to close)\x07\\" ;
+               """read foo;"\' """)  % (command, command) )
 
 #-------------------------------------------------------------------------------
 # Frontend class using ipython0 to do the prefiltering. 
@@ -70,8 +68,10 @@ class PrefilterFrontEnd(LineFrontEndBase):
             setattr(_ip.IP, 'magic_%s' % alias_name, magic)
         # FIXME: I should create a real file-like object dedicated to this
         # terminal
-        self.shell.output_trap = SyncOutputTrap(write_out=self.write,
-                                                write_err=self.write)
+        self.shell.output_trap = OutputTrap(
+                                out=FileLike(write_callback=self.write),
+                                err=FileLike(write_callback=self.write),
+                                            )
         # Capture and release the outputs, to make sure all the
         # shadow variables are set
         self.capture_output()
@@ -142,6 +142,7 @@ class PrefilterFrontEnd(LineFrontEndBase):
     def complete(self, line):
         word = line.split('\n')[-1].split(' ')[-1]
         completions = self.ipython0.complete(word)
+        # FIXME: The proper sort should be done in the complete method.
         key = lambda x: x.replace('_', '')
         completions.sort(key=key)
         if completions:
diff --git a/IPython/kernel/core/sync_output_trap.py b/IPython/kernel/core/file_like.py
similarity index 66%
rename from IPython/kernel/core/sync_output_trap.py
rename to IPython/kernel/core/file_like.py
index 31b204a..a09f47a 100644
--- a/IPython/kernel/core/sync_output_trap.py
+++ b/IPython/kernel/core/file_like.py
@@ -1,6 +1,6 @@
 # encoding: utf-8
 
-""" Redirects stdout/stderr to given write methods."""
+""" File like object that redirects its write calls to a given callback."""
 
 __docformat__ = "restructuredtext en"
 
@@ -11,12 +11,7 @@ __docformat__ = "restructuredtext en"
 #  the file COPYING, distributed as part of this software.
 #-------------------------------------------------------------------------------
 
-#-------------------------------------------------------------------------------
-# Imports
-#-------------------------------------------------------------------------------
-
 import sys
-from IPython.kernel.core.output_trap import OutputTrap 
 
 class FileLike(object):
     """ FileLike object that redirects all write to a callback.
@@ -26,8 +21,8 @@ class FileLike(object):
     """
     closed = False
 
-    def __init__(self, write):
-        self.write = write
+    def __init__(self, write_callback):
+        self.write = write_callback
 
     def flush(self):
         pass
@@ -45,23 +40,10 @@ class FileLike(object):
     def getvalue(self):
         return ''
 
+    def reset(self):
+        pass
 
-class SyncOutputTrap(OutputTrap):
-    """ Object which redirect text sent to stdout and stderr to write
-        callbacks.
-    """
-    
-    def __init__(self, write_out, write_err):
-        # Store callbacks
-        self.out = FileLike(write_out)
-        self.err = FileLike(write_err)
-
-        # Boolean to check if the stdout/stderr hook is set.
-        self.out_set = False
-        self.err_set = False
-
-    def clear(self):
-        """ Clear out the buffers.
-        """
+    def truncate(self):
         pass
 
+
diff --git a/IPython/kernel/core/output_trap.py b/IPython/kernel/core/output_trap.py
index 8e65662..c16571f 100644
--- a/IPython/kernel/core/output_trap.py
+++ b/IPython/kernel/core/output_trap.py
@@ -23,10 +23,16 @@ class OutputTrap(object):
     """ Object which can trap text sent to stdout and stderr.
     """
 
-    def __init__(self):
+    def __init__(self, out=None, err=None):
         # Filelike objects to store stdout/stderr text.
-        self.out = StringIO()
-        self.err = StringIO()
+        if out is None:
+            self.out = StringIO()
+        else:
+            self.out = out
+        if err is None:
+            self.err = StringIO()
+        else:
+            self.err = err
 
         # Boolean to check if the stdout/stderr hook is set.
         self.out_set = False
@@ -72,11 +78,11 @@ class OutputTrap(object):
         """ Clear out the buffers.
         """
 
-        self.out.close()
-        self.out = StringIO()
+        self.out.reset()
+        self.out.truncate()
 
-        self.err.close()
-        self.err = StringIO()
+        self.err.reset()
+        self.err.truncate()
 
     def add_to_message(self, message):
         """ Add the text from stdout and stderr to the message from the