# Copyright (C) 2010 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""Unicode-compatible command-line splitter for all platforms."""
import re
_whitespace_match = re.compile(u'\s', re.UNICODE).match
class _PushbackSequence(object):
def __init__(self, orig):
self._iter = iter(orig)
self._pushback_buffer = []
def next(self):
if len(self._pushback_buffer) > 0:
return self._pushback_buffer.pop()
else:
return self._iter.next()
def pushback(self, char):
self._pushback_buffer.append(char)
def __iter__(self):
return self
class _Whitespace(object):
def process(self, next_char, context):
if _whitespace_match(next_char):
if len(context.token) > 0:
return None
else:
return self
elif next_char in context.allowed_quote_chars:
context.quoted = True
return _Quotes(next_char, self)
elif next_char == u'\\':
return _Backslash(self)
else:
context.token.append(next_char)
return _Word()
class _Quotes(object):
def __init__(self, quote_char, exit_state):
self.quote_char = quote_char
self.exit_state = exit_state
def process(self, next_char, context):
if next_char == u'\\':
return _Backslash(self)
elif next_char == self.quote_char:
return self.exit_state
else:
context.token.append(next_char)
return self
class _Backslash(object):
# See http://msdn.microsoft.com/en-us/library/bb776391(VS.85).aspx
def __init__(self, exit_state):
self.exit_state = exit_state
self.count = 1
def process(self, next_char, context):
if next_char == u'\\':
self.count += 1
return self
elif next_char in context.allowed_quote_chars:
# 2N backslashes followed by a quote are N backslashes
context.token.append(u'\\' * (self.count/2))
# 2N+1 backslashes follwed by a quote are N backslashes followed by
# the quote which should not be processed as the start or end of
# the quoted arg
if self.count % 2 == 1:
# odd number of \ escapes the quote
context.token.append(next_char)
else:
# let exit_state handle next_char
context.seq.pushback(next_char)
self.count = 0
return self.exit_state
else:
# N backslashes not followed by a quote are just N backslashes
if self.count > 0:
context.token.append(u'\\' * self.count)
self.count = 0
# let exit_state handle next_char
context.seq.pushback(next_char)
return self.exit_state
def finish(self, context):
if self.count > 0:
context.token.append(u'\\' * self.count)
class _Word(object):
def process(self, next_char, context):
if _whitespace_match(next_char):
return None
elif next_char in context.allowed_quote_chars:
return _Quotes(next_char, self)
elif next_char == u'\\':
return _Backslash(self)
else:
context.token.append(next_char)
return self
class Splitter(object):
def __init__(self, command_line, single_quotes_allowed):
self.seq = _PushbackSequence(command_line)
self.allowed_quote_chars = u'"'
if single_quotes_allowed:
self.allowed_quote_chars += u"'"
def __iter__(self):
return self
def next(self):
quoted, token = self._get_token()
if token is None:
raise StopIteration
return quoted, token
def _get_token(self):
self.quoted = False
self.token = []
state = _Whitespace()
for next_char in self.seq:
state = state.process(next_char, self)
if state is None:
break
if not state is None and not getattr(state, 'finish', None) is None:
state.finish(self)
result = u''.join(self.token)
if not self.quoted and result == '':
result = None
return self.quoted, result
def split(unsplit, single_quotes_allowed=True):
splitter = Splitter(unsplit, single_quotes_allowed=single_quotes_allowed)
return [arg for quoted, arg in splitter]
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