def testVarExpandPass(self):

		varDict = { "a":"5", "b":"7", "c":"-5" }
		for key in varDict:
			result = varexpand( "$%s" % key, varDict )
			
			self.assertFalse( result != varDict[key],
				msg="Got %s != %s, from varexpand( %s, %s )" % \
					( result, varDict[key], "$%s" % key, varDict ) )
			result = varexpand( "${%s}" % key, varDict )
			self.assertFalse( result != varDict[key],
				msg="Got %s != %s, from varexpand( %s, %s )" % \
					( result, varDict[key], "${%s}" % key, varDict ) )

	def testVarExpandBackslashes(self):
		"""
		We want to behave like bash does when expanding a variable
		assignment in a sourced file, in which case it performs
		backslash removal for \\ and \$ but nothing more. It also
		removes escaped newline characters. Note that we don't
		handle escaped quotes here, since getconfig() uses shlex
		to handle that earlier.
		"""

		varDict = {}
		tests = [
			("\\", "\\"),
			("\\\\", "\\"),
			("\\\\\\", "\\\\"),
			("\\\\\\\\", "\\\\"),
			("\\$", "$"),
			("\\\\$", "\\$"),
			("\\a", "\\a"),
			("\\b", "\\b"),
			("\\n", "\\n"),
			("\\r", "\\r"),
			("\\t", "\\t"),
			("\\\n", ""),
			("\\\"", "\\\""),
			("\\'", "\\'"),
		]
		for test in tests:
			result = varexpand( test[0], varDict )
			self.assertFalse( result != test[1],
				msg="Got %s != %s from varexpand( %s, %s )" \
				% ( result, test[1], test[0], varDict ) )

	def testVarExpandFail(self):

		varDict = { "a":"5", "b":"7", "c":"15" }

		testVars = [ "fail" ]

		for var in testVars:
			result = varexpand( "$%s" % var, varDict )
			self.assertFalse( len(result),
				msg="Got %s == %s, from varexpand( %s, %s )" \
					% ( result, var, "$%s" % var, varDict ) )

			result = varexpand( "${%s}" % var, varDict )
			self.assertFalse( len(result),
				msg="Got %s == %s, from varexpand( %s, %s )" \
					% ( result, var, "${%s}" % var, varDict ) )

def file_get(baseurl,dest,conn=None,fcmd=None):
	"""(baseurl,dest,fcmd=) -- Takes a base url to connect to and read from.
	URI should be in the form <proto>://[user[:pass]@]<site>[:port]<path>"""

	if not fcmd:
		return file_get_lib(baseurl,dest,conn)

	variables = {
		"DISTDIR": dest,
		"URI":     baseurl,
		"FILE":    os.path.basename(baseurl)
	}

	from portage.util import varexpand
	from portage.process import spawn
	myfetch = portage.util.shlex_split(fcmd)
	myfetch = [varexpand(x, mydict=variables) for x in myfetch]
	fd_pipes= {
		0:sys.stdin.fileno(),
		1:sys.stdout.fileno(),
		2:sys.stdout.fileno()
	}
	retval = spawn(myfetch, env=os.environ.copy(), fd_pipes=fd_pipes)
	if retval != os.EX_OK:
		sys.stderr.write(_("Fetcher exited with a failure condition.\n"))
		return 0
	return 1

def file_get(baseurl,dest,conn=None,fcmd=None,filename=None):
	"""(baseurl,dest,fcmd=) -- Takes a base url to connect to and read from.
	URI should be in the form <proto>://[user[:pass]@]<site>[:port]<path>"""

	if not fcmd:

		warnings.warn("Use of portage.getbinpkg.file_get() without the fcmd "
			"parameter is deprecated", DeprecationWarning, stacklevel=2)

		return file_get_lib(baseurl,dest,conn)
	if not filename:
		filename = os.path.basename(baseurl)

	variables = {
		"DISTDIR": dest,
		"URI":     baseurl,
		"FILE":    filename
	}

	from portage.util import varexpand
	from portage.process import spawn
	myfetch = portage.util.shlex_split(fcmd)
	myfetch = [varexpand(x, mydict=variables) for x in myfetch]
	fd_pipes= {
		0:sys.__stdin__.fileno(),
		1:sys.__stdout__.fileno(),
		2:sys.__stdout__.fileno()
	}
	sys.__stdout__.flush()
	sys.__stderr__.flush()
	retval = spawn(myfetch, env=os.environ.copy(), fd_pipes=fd_pipes)
	if retval != os.EX_OK:
		sys.stderr.write(_("Fetcher exited with a failure condition.\n"))
		return 0
	return 1

	def testVarExpandSingleQuotes(self):
		
		varDict = { "a":"5" }
		tests = [ ("\'${a}\'", "\'${a}\'") ]
		for test in tests:
			result = varexpand( test[0], varDict )
			self.assertFalse( result != test[1],
				msg="Got %s != %s from varexpand( %s, %s )" \
				% ( result, test[1], test[0], varDict ) )

	def testVarExpandDoubleQuotes(self):
		
		varDict = { "a":"5" }
		tests = [ ("\"${a}\"", "\"5\"") ]
		for test in tests:
			result = varexpand( test[0], varDict )
			self.failIf( result != test[1],
				msg="Got %s != %s from varexpand( %s, %s )" \
				% ( result, test[1], test[0], varDict ) )

	def _start_gpg_proc(self):
		gpg_vars = self.gpg_vars
		if gpg_vars is None:
			gpg_vars = {}
		else:
			gpg_vars = gpg_vars.copy()
		gpg_vars["FILE"] = self._manifest_path
		gpg_cmd = varexpand(self.gpg_cmd, mydict=gpg_vars)
		gpg_cmd = shlex_split(gpg_cmd)
		gpg_proc = PopenProcess(proc=subprocess.Popen(gpg_cmd))
		self._start_task(gpg_proc, self._gpg_proc_exit)

def file_get(baseurl=None, dest=None, conn=None, fcmd=None, filename=None,
	fcmd_vars=None):
	"""Takes a base url to connect to and read from.
	URI should be in the form <proto>://[user[:pass]@]<site>[:port]<path>"""

	if not fcmd:

		warnings.warn("Use of portage.getbinpkg.file_get() without the fcmd "
			"parameter is deprecated", DeprecationWarning, stacklevel=2)

		return file_get_lib(baseurl, dest, conn)

	variables = {}

	if fcmd_vars is not None:
		variables.update(fcmd_vars)

	if "DISTDIR" not in variables:
		if dest is None:
			raise portage.exception.MissingParameter(
				_("%s is missing required '%s' key") %
				("fcmd_vars", "DISTDIR"))
		variables["DISTDIR"] = dest

	if "URI" not in variables:
		if baseurl is None:
			raise portage.exception.MissingParameter(
				_("%s is missing required '%s' key") %
				("fcmd_vars", "URI"))
		variables["URI"] = baseurl

	if "FILE" not in variables:
		if filename is None:
			filename = os.path.basename(variables["URI"])
		variables["FILE"] = filename

	from portage.util import varexpand
	from portage.process import spawn
	myfetch = portage.util.shlex_split(fcmd)
	myfetch = [varexpand(x, mydict=variables) for x in myfetch]
	fd_pipes = {
		0: portage._get_stdin().fileno(),
		1: sys.__stdout__.fileno(),
		2: sys.__stdout__.fileno()
	}
	sys.__stdout__.flush()
	sys.__stderr__.flush()
	retval = spawn(myfetch, env=os.environ.copy(), fd_pipes=fd_pipes)
	if retval != os.EX_OK:
		sys.stderr.write(_("Fetcher exited with a failure condition.\n"))
		return 0
	return 1

	def _clean_logs(clean_cmd, settings):
		logdir = settings.get("PORT_LOGDIR")
		if logdir is None or not os.path.isdir(logdir):
			return 78

		variables = {"PORT_LOGDIR" : logdir}
		cmd = [varexpand(x, mydict=variables) for x in clean_cmd]

		try:
			rval = portage.process.spawn(cmd, env=os.environ)
		except portage.exception.CommandNotFound:
			rval = 127
		return rval

	def _start_gpg_proc(self):
		gpg_vars = self.gpg_vars
		if gpg_vars is None:
			gpg_vars = {}
		else:
			gpg_vars = gpg_vars.copy()
		gpg_vars["FILE"] = self._manifest_path
		gpg_cmd = varexpand(self.gpg_cmd, mydict=gpg_vars)
		gpg_cmd = shlex_split(gpg_cmd)
		gpg_proc = PopenProcess(proc=subprocess.Popen(gpg_cmd,
			stdout=subprocess.PIPE, stderr=subprocess.STDOUT))
		# PipeLogger echos output and efficiently monitors for process
		# exit by listening for the stdout EOF event.
		gpg_proc.pipe_reader = PipeLogger(background=self.background,
			input_fd=gpg_proc.proc.stdout, scheduler=self.scheduler)
		self._start_task(gpg_proc, self._gpg_proc_exit)

	def add(self, entry):
		"""
		Add one NEEDED.ELF.2 entry, for inclusion in the generated
		REQUIRES and PROVIDES values.

		@param entry: NEEDED.ELF.2 entry
		@type entry: NeededEntry
		"""

		multilib_cat = entry.multilib_category
		if multilib_cat is None:
			# This usage is invalid. The caller must ensure that
			# the multilib category data is supplied here.
			raise AssertionError(
				"Missing multilib category data: %s" % entry.filename)

		self._basename_map.setdefault(
			os.path.basename(entry.filename), []).append(entry)

		if entry.needed and (
			self._requires_exclude is None or
			self._requires_exclude.match(
			entry.filename.lstrip(os.sep)) is None):
			runpaths = frozenset()
			if entry.runpaths is not None:
				expand = {"ORIGIN": os.path.dirname(entry.filename)}
				runpaths = frozenset(normalize_path(varexpand(x, expand,
					error_leader=lambda: "%s: DT_RUNPATH: " % entry.filename))
					for x in entry.runpaths)
			for x in entry.needed:
				if (self._requires_exclude is None or
					self._requires_exclude.match(x) is None):
					self._requires_map[multilib_cat][x].add(runpaths)

		if entry.soname:
			self._provides_unfiltered.setdefault(
				multilib_cat, set()).add(entry.soname)

		if entry.soname and (
			self._provides_exclude is None or
			(self._provides_exclude.match(
			entry.filename.lstrip(os.sep)) is None and
			self._provides_exclude.match(entry.soname) is None)):
			self._provides_map.setdefault(
				multilib_cat, set()).add(entry.soname)

def read_config(mandatory_opts):
	eprefix = portage.settings["EPREFIX"]
	if portage._not_installed:
		config_path = os.path.join(portage.PORTAGE_BASE_PATH, "cnf", "dispatch-conf.conf")
	else:
		config_path = os.path.join(eprefix or os.sep, "etc/dispatch-conf.conf")
	loader = KeyValuePairFileLoader(config_path, None)
	opts, _errors = loader.load()
	if not opts:
		print(_('dispatch-conf: Error reading /etc/dispatch-conf.conf; fatal'), file=sys.stderr)
		sys.exit(1)

	# Handle quote removal here, since KeyValuePairFileLoader doesn't do that.
	quotes = "\"'"
	for k, v in opts.items():
		if v[:1] in quotes and v[:1] == v[-1:]:
			opts[k] = v[1:-1]

	for key in mandatory_opts:
		if key not in opts:
			if key == "merge":
				opts["merge"] = "sdiff --suppress-common-lines --output='%s' '%s' '%s'"
			else:
				print(_('dispatch-conf: Missing option "%s" in /etc/dispatch-conf.conf; fatal') % (key,), file=sys.stderr)

	# archive-dir supports ${EPREFIX} expansion, in order to avoid hardcoding
	variables = {"EPREFIX": eprefix}
	opts['archive-dir'] = varexpand(opts['archive-dir'], mydict=variables)

	if not os.path.exists(opts['archive-dir']):
		os.mkdir(opts['archive-dir'])
		# Use restrictive permissions by default, in order to protect
		# against vulnerabilities (like bug #315603 involving rcs).
		os.chmod(opts['archive-dir'], 0o700)
	elif not os.path.isdir(opts['archive-dir']):
		print(_('dispatch-conf: Config archive dir [%s] must exist; fatal') % (opts['archive-dir'],), file=sys.stderr)
		sys.exit(1)

	return opts

def ionice(settings):

	ionice_cmd = settings.get("PORTAGE_IONICE_COMMAND")
	if ionice_cmd:
		ionice_cmd = portage.util.shlex_split(ionice_cmd)
	if not ionice_cmd:
		return

	from portage.util import varexpand
	variables = {"PID" : str(os.getpid())}
	cmd = [varexpand(x, mydict=variables) for x in ionice_cmd]

	try:
		rval = portage.process.spawn(cmd, env=os.environ)
	except portage.exception.CommandNotFound:
		# The OS kernel probably doesn't support ionice,
		# so return silently.
		return

	if rval != os.EX_OK:
		out = portage.output.EOutput()
		out.eerror("PORTAGE_IONICE_COMMAND returned %d" % (rval,))
		out.eerror("See the make.conf(5) man page for PORTAGE_IONICE_COMMAND usage instructions.")

#.........这里部分代码省略.........
					fields[1] = fields[1][root_len:]
					owner = plibs.pop(fields[1], None)
					lines.append((owner, "scanelf", ";".join(fields)))
				proc.wait()
				proc.stdout.close()

		if plibs:
			# Preserved libraries that did not appear in the scanelf output.
			# This is known to happen with statically linked libraries.
			# Generate dummy lines for these, so we can assume that every
			# preserved library has an entry in self._obj_properties. This
			# is important in order to prevent findConsumers from raising
			# an unwanted KeyError.
			for x, cpv in plibs.items():
				lines.append((cpv, "plibs", ";".join(['', x, '', '', ''])))

		# Share identical frozenset instances when available,
		# in order to conserve memory.
		frozensets = {}

		for owner, location, l in lines:
			l = l.rstrip("\n")
			if not l:
				continue
			if '\0' in l:
				# os.stat() will raise "TypeError: must be encoded string
				# without NULL bytes, not str" in this case.
				writemsg_level(_("\nLine contains null byte(s) " \
					"in %s: %s\n\n") % (location, l),
					level=logging.ERROR, noiselevel=-1)
				continue
			try:
				entry = NeededEntry.parse(location, l)
			except InvalidData as e:
				writemsg_level("\n%s\n\n" % (e,),
					level=logging.ERROR, noiselevel=-1)
				continue

			# If NEEDED.ELF.2 contains the new multilib category field,
			# then use that for categorization. Otherwise, if a mapping
			# exists, map e_machine (entry.arch) to an approximate
			# multilib category. If all else fails, use e_machine, just
			# as older versions of portage did.
			arch = entry.multilib_category
			if arch is None:
				arch = _approx_multilib_categories.get(
					entry.arch, entry.arch)

			obj = entry.filename
			soname = entry.soname
			expand = {"ORIGIN": os.path.dirname(entry.filename)}
			path = frozenset(normalize_path(
				varexpand(x, expand, error_leader=lambda: "%s: " % location))
				for x in entry.runpaths)
			path = frozensets.setdefault(path, path)
			needed = frozenset(entry.needed)

			needed = frozensets.setdefault(needed, needed)

			obj_key = self._obj_key(obj)
			indexed = True
			myprops = obj_properties.get(obj_key)
			if myprops is None:
				indexed = False
				myprops = self._obj_properties_class(
					arch, needed, path, soname, [], owner)
				obj_properties[obj_key] = myprops
			# All object paths are added into the obj_properties tuple.
			myprops.alt_paths.append(obj)

			# Don't index the same file more that once since only one
			# set of data can be correct and therefore mixing data
			# may corrupt the index (include_file overrides previously
			# installed).
			if indexed:
				continue

			arch_map = libs.get(arch)
			if arch_map is None:
				arch_map = {}
				libs[arch] = arch_map
			if soname:
				soname_map = arch_map.get(soname)
				if soname_map is None:
					soname_map = self._soname_map_class(
						providers=[], consumers=[])
					arch_map[soname] = soname_map
				soname_map.providers.append(obj_key)
			for needed_soname in needed:
				soname_map = arch_map.get(needed_soname)
				if soname_map is None:
					soname_map = self._soname_map_class(
						providers=[], consumers=[])
					arch_map[needed_soname] = soname_map
				soname_map.consumers.append(obj_key)

		for arch, sonames in libs.items():
			for soname_node in sonames.values():
				soname_node.providers = tuple(set(soname_node.providers))
				soname_node.consumers = tuple(set(soname_node.consumers))

#.........这里部分代码省略.........
							del e
							fetched = 0
						else:
							if mystat.st_size < fetch_resume_size:
								writemsg(_(">>> Deleting distfile with size "
									"%d (smaller than " "PORTAGE_FETCH_RESU"
									"ME_MIN_SIZE)\n") % mystat.st_size)
								try:
									os.unlink(myfile_path)
								except OSError as e:
									if e.errno not in \
										(errno.ENOENT, errno.ESTALE):
										raise
									del e
								fetched = 0
					if fetched == 1:
						#resume mode:
						writemsg(_(">>> Resuming download...\n"))
						locfetch=resumecommand
						command_var = resumecommand_var
					else:
						#normal mode:
						locfetch=fetchcommand
						command_var = fetchcommand_var
					writemsg_stdout(_(">>> Downloading '%s'\n") % \
						_hide_url_passwd(loc))
					variables = {
						"DISTDIR": mysettings["DISTDIR"],
						"URI":     loc,
						"FILE":    myfile
					}

					myfetch = shlex_split(locfetch)
					myfetch = [varexpand(x, mydict=variables) for x in myfetch]
					myret = -1
					try:

						myret = _spawn_fetch(mysettings, myfetch)

					finally:
						try:
							apply_secpass_permissions(myfile_path,
								gid=portage_gid, mode=0o664, mask=0o2)
						except FileNotFound:
							pass
						except PortageException as e:
							if not os.access(myfile_path, os.R_OK):
								writemsg(_("!!! Failed to adjust permissions:"
									" %s\n") % str(e), noiselevel=-1)
							del e

					# If the file is empty then it's obviously invalid.  Don't
					# trust the return value from the fetcher.  Remove the
					# empty file and try to download again.
					try:
						if os.stat(myfile_path).st_size == 0:
							os.unlink(myfile_path)
							fetched = 0
							continue
					except EnvironmentError:
						pass

					if mydigests is not None and myfile in mydigests:
						try:
							mystat = os.stat(myfile_path)
						except OSError as e:

	def _start(self):
		tar_options = ""
		if "xattr" in self.features:
			process = subprocess.Popen(["tar", "--help"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
			output = process.communicate()[0]
			if b"--xattrs" in output:
				tar_options = ["--xattrs", "--xattrs-include='*'"]
				for x in portage.util.shlex_split(self.env.get("PORTAGE_XATTR_EXCLUDE", "")):
					tar_options.append(portage._shell_quote("--xattrs-exclude=%s" % x))
				tar_options = " ".join(tar_options)

		decomp = _compressors.get(compression_probe(self.pkg_path))
		if decomp is not None:
			decomp_cmd = decomp.get("decompress")
		else:
			decomp_cmd = None
		if decomp_cmd is None:
			self.scheduler.output("!!! %s\n" %
				_("File compression header unrecognized: %s") %
				self.pkg_path, log_path=self.logfile,
				background=self.background, level=logging.ERROR)
			self.returncode = 1
			self._async_wait()
			return

		try:
			decompression_binary = shlex_split(varexpand(decomp_cmd, mydict=self.env))[0]
		except IndexError:
			decompression_binary = ""

		if find_binary(decompression_binary) is None:
			# Try alternative command if it exists
			if _compressors.get(compression_probe(self.pkg_path)).get("decompress_alt"):
				decomp_cmd = _compressors.get(
					compression_probe(self.pkg_path)).get("decompress_alt")
			try:
				decompression_binary = shlex_split(varexpand(decomp_cmd, mydict=self.env))[0]
			except IndexError:
				decompression_binary = ""

			if find_binary(decompression_binary) is None:
				missing_package = _compressors.get(compression_probe(self.pkg_path)).get("package")
				self.scheduler.output("!!! %s\n" %
					_("File compression unsupported %s.\n Command was: %s.\n Maybe missing package: %s") %
					(self.pkg_path, varexpand(decomp_cmd, mydict=self.env), missing_package), log_path=self.logfile,
					background=self.background, level=logging.ERROR)
				self.returncode = 1
				self._async_wait()
				return

		pkg_xpak = portage.xpak.tbz2(self.pkg_path)
		pkg_xpak.scan()

		# SIGPIPE handling (128 + SIGPIPE) should be compatible with
		# assert_sigpipe_ok() that's used by the ebuild unpack() helper.
		self.args = [self._shell_binary, "-c",
			("cmd0=(head -c %d -- %s) cmd1=(%s) cmd2=(tar -xp %s -C %s -f -); " + \
			'"${cmd0[@]}" | "${cmd1[@]}" | "${cmd2[@]}"; ' + \
			"p=(${PIPESTATUS[@]}) ; for i in {0..2}; do " + \
			"if [[ ${p[$i]} != 0 && ${p[$i]} != %d ]] ; then " + \
			"echo command $(eval \"echo \\\"'\\${cmd$i[*]}'\\\"\") " + \
			"failed with status ${p[$i]} ; exit ${p[$i]} ; fi ; done; " + \
			"if [ ${p[$i]} != 0 ] ; then " + \
			"echo command $(eval \"echo \\\"'\\${cmd$i[*]}'\\\"\") " + \
			"failed with status ${p[$i]} ; exit ${p[$i]} ; fi ; " + \
			"exit 0 ;") % \
			(pkg_xpak.filestat.st_size - pkg_xpak.xpaksize,
			portage._shell_quote(self.pkg_path),
			decomp_cmd,
			tar_options,
			portage._shell_quote(self.image_dir),
			128 + signal.SIGPIPE)]

		SpawnProcess._start(self)