Create fallback with old arg_split, incase CommandLineToArgvW is missing.

IPython/utils/_process_win32.py

@@ -1,176 +1,201 b''
 """Windows-specific implementation of process utilities.
 
 This file is only meant to be imported by process.py, not by end-users.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011  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
 
 # stdlib
 import os
 import sys
 import ctypes
 
 from ctypes import c_int, POINTER
 from ctypes.wintypes import LPCWSTR, HLOCAL
 from subprocess import STDOUT
 
 # our own imports
 from ._process_common import read_no_interrupt, process_handler
 from . import py3compat
 from . import text
 
 #-----------------------------------------------------------------------------
 # Function definitions
 #-----------------------------------------------------------------------------
 
 class AvoidUNCPath(object):
     """A context manager to protect command execution from UNC paths.
 
     In the Win32 API, commands can't be invoked with the cwd being a UNC path.
     This context manager temporarily changes directory to the 'C:' drive on
     entering, and restores the original working directory on exit.
 
     The context manager returns the starting working directory *if* it made a
     change and None otherwise, so that users can apply the necessary adjustment
     to their system calls in the event of a change.
 
     Example
     -------
     ::
         cmd = 'dir'
         with AvoidUNCPath() as path:
             if path is not None:
                 cmd = '"pushd %s &&"%s' % (path, cmd)
             os.system(cmd)
     """
     def __enter__(self):
         self.path = os.getcwdu()
         self.is_unc_path = self.path.startswith(r"\\")
         if self.is_unc_path:
             # change to c drive (as cmd.exe cannot handle UNC addresses)
             os.chdir("C:")
             return self.path
         else:
             # We return None to signal that there was no change in the working
             # directory
             return None
 
     def __exit__(self, exc_type, exc_value, traceback):
         if self.is_unc_path:
             os.chdir(self.path)
 
 
 def _find_cmd(cmd):
     """Find the full path to a .bat or .exe using the win32api module."""
     try:
         from win32api import SearchPath
     except ImportError:
         raise ImportError('you need to have pywin32 installed for this to work')
     else:
         PATH = os.environ['PATH']
         extensions = ['.exe', '.com', '.bat', '.py']
         path = None
         for ext in extensions:
             try:
                 path = SearchPath(PATH, cmd + ext)[0]
             except:
                 pass
         if path is None:
             raise OSError("command %r not found" % cmd)
         else:
             return path
 
 
 def _system_body(p):
     """Callback for _system."""
     enc = text.getdefaultencoding()
     for line in read_no_interrupt(p.stdout).splitlines():
         line = line.decode(enc, 'replace')
         print(line, file=sys.stdout)
     for line in read_no_interrupt(p.stderr).splitlines():
         line = line.decode(enc, 'replace')
         print(line, file=sys.stderr)
 
     # Wait to finish for returncode
     return p.wait()
 
 
 def system(cmd):
     """Win32 version of os.system() that works with network shares.
 
     Note that this implementation returns None, as meant for use in IPython.
 
     Parameters
     ----------
     cmd : str
       A command to be executed in the system shell.
 
     Returns
     -------
     None : we explicitly do NOT return the subprocess status code, as this
     utility is meant to be used extensively in IPython, where any return value
     would trigger :func:`sys.displayhook` calls.
     """
     with AvoidUNCPath() as path:
         if path is not None:
             cmd = '"pushd %s &&"%s' % (path, cmd)
         return process_handler(cmd, _system_body)
 
 
 def getoutput(cmd):
     """Return standard output of executing cmd in a shell.
 
     Accepts the same arguments as os.system().
 
     Parameters
     ----------
     cmd : str
       A command to be executed in the system shell.
 
     Returns
     -------
     stdout : str
     """
 
     with AvoidUNCPath() as path:
         if path is not None:
             cmd = '"pushd %s &&"%s' % (path, cmd)
         out = process_handler(cmd, lambda p: p.communicate()[0], STDOUT)
 
     if out is None:
         out = ''
     return out
 
-
-CommandLineToArgvW = ctypes.windll.shell32.CommandLineToArgvW
-CommandLineToArgvW.arg_types = [LPCWSTR, POINTER(c_int)]
-CommandLineToArgvW.res_types = [POINTER(LPCWSTR)]
-LocalFree = ctypes.windll.kernel32.LocalFree
-LocalFree.res_type = HLOCAL
-LocalFree.arg_types = [HLOCAL]
-
-def arg_split(commandline, posix=False):
-    """Split a command line's arguments in a shell-like manner.
-
-    This is a special version for windows that use a ctypes call to CommandLineToArgvW
-    to do the argv splitting. The posix paramter is ignored.
-    """
-    #CommandLineToArgvW returns path to executable if called with empty string.
-    if commandline.strip() == "":
-        return []
-    argvn = c_int()
-    result_pointer = CommandLineToArgvW(py3compat.cast_unicode(commandline.lstrip()), ctypes.byref(argvn))
-    result_array_type = LPCWSTR * argvn.value
-    result = [arg for arg in result_array_type.from_address(result_pointer)]
-    retval = LocalFree(result_pointer)
-    return result
+try:
+    CommandLineToArgvW = ctypes.windll.shell32.CommandLineToArgvW
+    CommandLineToArgvW.arg_types = [LPCWSTR, POINTER(c_int)]
+    CommandLineToArgvW.res_types = [POINTER(LPCWSTR)]
+    LocalFree = ctypes.windll.kernel32.LocalFree
+    LocalFree.res_type = HLOCAL
+    LocalFree.arg_types = [HLOCAL]
+    
+    def arg_split(commandline, posix=False):
+        """Split a command line's arguments in a shell-like manner.
+
+        This is a special version for windows that use a ctypes call to CommandLineToArgvW
+        to do the argv splitting. The posix paramter is ignored.
+        """
+        #CommandLineToArgvW returns path to executable if called with empty string.
+        if commandline.strip() == "":
+            return []
+        argvn = c_int()
+        result_pointer = CommandLineToArgvW(py3compat.cast_unicode(commandline.lstrip()), ctypes.byref(argvn))
+        result_array_type = LPCWSTR * argvn.value
+        result = [arg for arg in result_array_type.from_address(result_pointer)]
+        retval = LocalFree(result_pointer)
+        return result
+except AttributeError:
+    import shlex
+    #alternative if CommandLineToArgvW is not available
+    def arg_split(s, posix=False):
+        """Split a command line's arguments in a shell-like manner.
+
+        This is a modified version of the standard library's shlex.split()
+        function, but with a default of posix=False for splitting, so that quotes
+        in inputs are respected."""
+
+        # Unfortunately, python's shlex module is buggy with unicode input:
+        # http://bugs.python.org/issue1170
+        # At least encoding the input when it's unicode seems to help, but there
+        # may be more problems lurking.  Apparently this is fixed in python3.
+        is_unicode = False
+        if (not py3compat.PY3) and isinstance(s, unicode):
+            is_unicode = True
+            s = s.encode('utf-8')
+        lex = shlex.shlex(s, posix=posix)
+        lex.whitespace_split = True
+        tokens = list(lex)
+        if is_unicode:
+            # Convert the tokens back to unicode.
+            tokens = [x.decode('utf-8') for x in tokens]
+        return tokens