def _prepare_fake_distdir(settings, alist):
	orig_distdir = settings["DISTDIR"]
	edpath = os.path.join(settings["PORTAGE_BUILDDIR"], "distdir")
	portage.util.ensure_dirs(edpath, gid=portage_gid, mode=0o755)

	# Remove any unexpected files or directories.
	for x in os.listdir(edpath):
		symlink_path = os.path.join(edpath, x)
		st = os.lstat(symlink_path)
		if x in alist and stat.S_ISLNK(st.st_mode):
			continue
		if stat.S_ISDIR(st.st_mode):
			shutil.rmtree(symlink_path)
		else:
			os.unlink(symlink_path)

	# Check for existing symlinks and recreate if necessary.
	for x in alist:
		symlink_path = os.path.join(edpath, x)
		target = os.path.join(orig_distdir, x)
		try:
			link_target = os.readlink(symlink_path)
		except OSError:
			os.symlink(target, symlink_path)
		else:
			if link_target != target:
				os.unlink(symlink_path)
				os.symlink(target, symlink_path)

def hardlock_cleanup(path, remove_all_locks=False):
	myhost = os.uname()[1]
	mydl = os.listdir(path)

	results = []
	mycount = 0

	mylist = {}
	for x in mydl:
		if os.path.isfile(path + "/" + x):
			parts = x.split(".hardlock-")
			if len(parts) == 2:
				filename = parts[0][1:]
				hostpid  = parts[1].split("-")
				host  = "-".join(hostpid[:-1])
				pid   = hostpid[-1]
				
				if filename not in mylist:
					mylist[filename] = {}
				if host not in mylist[filename]:
					mylist[filename][host] = []
				mylist[filename][host].append(pid)

				mycount += 1


	results.append(_("Found %(count)s locks") % {"count": mycount})
	
	for x in mylist:
		if myhost in mylist[x] or remove_all_locks:
			mylockname = hardlock_name(path + "/" + x)
			if hardlink_is_mine(mylockname, path + "/" + x) or \
			   not os.path.exists(path + "/" + x) or \
				 remove_all_locks:
				for y in mylist[x]:
					for z in mylist[x][y]:
						filename = path + "/." + x + ".hardlock-" + y + "-" + z
						if filename == mylockname:
							continue
						try:
							# We're sweeping through, unlinking everyone's locks.
							os.unlink(filename)
							results.append(_("Unlinked: ") + filename)
						except OSError:
							pass
				try:
					os.unlink(path + "/" + x)
					results.append(_("Unlinked: ") + path + "/" + x)
					os.unlink(mylockname)
					results.append(_("Unlinked: ") + mylockname)
				except OSError:
					pass
			else:
				try:
					os.unlink(mylockname)
					results.append(_("Unlinked: ") + mylockname)
				except OSError:
					pass

	return results

def grab_updates(updpath, prev_mtimes=None):
	"""Returns all the updates from the given directory as a sorted list of
	tuples, each containing (file_path, statobj, content).  If prev_mtimes is
	given then only updates with differing mtimes are considered."""
	try:
		mylist = os.listdir(updpath)
	except OSError as oe:
		if oe.errno == errno.ENOENT:
			raise DirectoryNotFound(updpath)
		raise
	if prev_mtimes is None:
		prev_mtimes = {}
	# validate the file name (filter out CVS directory, etc...)
	mylist = [myfile for myfile in mylist if len(myfile) == 7 and myfile[1:3] == "Q-"]
	if len(mylist) == 0:
		return []
	
	# update names are mangled to make them sort properly
	mylist = [myfile[3:]+"-"+myfile[:2] for myfile in mylist]
	mylist.sort()
	mylist = [myfile[5:]+"-"+myfile[:4] for myfile in mylist]

	update_data = []
	for myfile in mylist:
		file_path = os.path.join(updpath, myfile)
		mystat = os.stat(file_path)
		if file_path not in prev_mtimes or \
		long(prev_mtimes[file_path]) != mystat[stat.ST_MTIME]:
			content = codecs.open(_unicode_encode(file_path,
				encoding=_encodings['fs'], errors='strict'),
				mode='r', encoding=_encodings['repo.content'], errors='replace'
				).read()
			update_data.append((file_path, mystat, content))
	return update_data

	def __iter__(self):
		"""generator for walking the dir struct"""
		dirs = [(0, self.location)]
		len_base = len(self.location)
		while dirs:
			depth, dir_path = dirs.pop()
			try:
				dir_list = os.listdir(dir_path)
			except OSError as e:
				if e.errno != errno.ENOENT:
					raise
				del e
				continue
			for l in dir_list:
				p = os.path.join(dir_path, l)
				try:
					st = os.lstat(p)
				except OSError:
					# Cache entry disappeared.
					continue
				if stat.S_ISDIR(st.st_mode):
					# Only recurse 1 deep, in order to avoid iteration over
					# entries from another nested cache instance. This can
					# happen if the user nests an overlay inside
					# /usr/portage/local as in bug #302764.
					if depth < 1:
						dirs.append((depth+1, p))
					continue

				try:
					yield _pkg_str(p[len_base+1:])
				except InvalidData:
					continue

def collect_ebuild_messages(path):
	""" Collect elog messages generated by the bash logging function stored 
		at 'path'.
	"""
	mylogfiles = None
	try:
		mylogfiles = os.listdir(path)
	except OSError:
		pass
	# shortcut for packages without any messages
	if not mylogfiles:
		return {}
	# exploit listdir() file order so we process log entries in chronological order
	mylogfiles.reverse()
	logentries = {}
	for msgfunction in mylogfiles:
		filename = os.path.join(path, msgfunction)
		if msgfunction not in EBUILD_PHASES:
			writemsg(_("!!! can't process invalid log file: %s\n") % filename,
				noiselevel=-1)
			continue
		if not msgfunction in logentries:
			logentries[msgfunction] = []
		lastmsgtype = None
		msgcontent = []
		f = io.open(_unicode_encode(filename,
			encoding=_encodings['fs'], errors='strict'),
			mode='r', encoding=_encodings['repo.content'], errors='replace')
		for l in f:
			l = l.rstrip('\n')
			if not l:
				continue
			try:
				msgtype, msg = l.split(" ", 1)
			except ValueError:
				writemsg(_("!!! malformed entry in "
					"log file: '%s'\n") % filename, noiselevel=-1)
				continue

			if lastmsgtype is None:
				lastmsgtype = msgtype
			
			if msgtype == lastmsgtype:
				msgcontent.append(msg)
			else:
				if msgcontent:
					logentries[msgfunction].append((lastmsgtype, msgcontent))
				msgcontent = [msg]
			lastmsgtype = msgtype
		f.close()
		if msgcontent:
			logentries[msgfunction].append((lastmsgtype, msgcontent))

	# clean logfiles to avoid repetitions
	for f in mylogfiles:
		try:
			os.unlink(os.path.join(path, f))
		except OSError:
			pass
	return logentries

def have_ebuild_dir(path, maxdepth=3):
	""" 
	Try to figure out if 'path' or a subdirectory contains one or more
	ebuild files named appropriately for their parent directory.
	"""
	stack = [(normalize_path(path), 1)]
	while stack:
		path, depth = stack.pop()
		basename = os.path.basename(path)
		try:
			listdir = os.listdir(path)
		except OSError:
			continue
		for filename in listdir:
			abs_filename = os.path.join(path, filename)
			try:
				st = os.stat(abs_filename)
			except OSError:
				continue
			if stat.S_ISDIR(st.st_mode):
				if depth < maxdepth:
					stack.append((abs_filename, depth + 1))
			elif stat.S_ISREG(st.st_mode):
				if filename.endswith(".ebuild") and \
					filename.startswith(basename + "-"):
					return os.path.dirname(os.path.dirname(path))

	def _get_all_modules(self):
		"""scans the emaint modules dir for loadable modules

		@rtype: dictionary of module_plugins
		"""
		module_dir =  self._module_path
		importables = []
		names = os.listdir(module_dir)
		for entry in names:
			# skip any __init__ or __pycache__ files or directories
			if entry.startswith('__'):
				continue
			try:
				# test for statinfo to ensure it should a real module
				# it will bail if it errors
				os.lstat(os.path.join(module_dir, entry, '__init__.py'))
				importables.append(entry)
			except EnvironmentError:
				pass
		kids = {}
		for entry in importables:
			new_module = Module(entry, self._namepath)
			for module_name in new_module.kids:
				kid = new_module.kids[module_name]
				kid['parent'] = new_module
				kids[kid['name']] = kid
			self.parents.append(entry)
		return kids

def get_glsa_list(myconfig):
	"""
	Returns a list of all available GLSAs in the given repository
	by comparing the filelist there with the pattern described in
	the config.

	@type	myconfig: portage.config
	@param	myconfig: Portage settings instance

	@rtype:		List of Strings
	@return:	a list of GLSA IDs in this repository
	"""
	rValue = []

	if "GLSA_DIR" in myconfig:
		repository = myconfig["GLSA_DIR"]
	else:
		repository = os.path.join(myconfig["PORTDIR"], "metadata", "glsa")

	if not os.access(repository, os.R_OK):
		return []
	dirlist = os.listdir(repository)
	prefix = "glsa-"
	suffix = ".xml"

	for f in dirlist:
		try:
			if f[:len(prefix)] == prefix and f[-1*len(suffix):] == suffix:
				rValue.append(f[len(prefix):-1*len(suffix)])
		except IndexError:
			pass
	return rValue

def grablines(myfilename, recursive=0, remember_source_file=False):
	mylines=[]
	if recursive and os.path.isdir(myfilename):
		if os.path.basename(myfilename) in _ignorecvs_dirs:
			return mylines
		dirlist = os.listdir(myfilename)
		dirlist.sort()
		for f in dirlist:
			if not f.startswith(".") and not f.endswith("~"):
				mylines.extend(grablines(
					os.path.join(myfilename, f), recursive, remember_source_file))
	else:
		try:
			myfile = io.open(_unicode_encode(myfilename,
				encoding=_encodings['fs'], errors='strict'),
				mode='r', encoding=_encodings['content'], errors='replace')
			if remember_source_file:
				mylines = [(line, myfilename) for line in myfile.readlines()]
			else:
				mylines = myfile.readlines()
			myfile.close()
		except IOError as e:
			if e.errno == PermissionDenied.errno:
				raise PermissionDenied(myfilename)
			pass
	return mylines

def cacheddir(my_original_path, ignorecvs, ignorelist, EmptyOnError, followSymlinks=True):
	mypath = normalize_path(my_original_path)
	try:
		pathstat = os.stat(mypath)
		if not stat.S_ISDIR(pathstat.st_mode):
			raise DirectoryNotFound(mypath)
	except EnvironmentError as e:
		if e.errno == PermissionDenied.errno:
			raise PermissionDenied(mypath)
		del e
		return [], []
	except PortageException:
		return [], []
	else:
		try:
			fpaths = os.listdir(mypath)
		except EnvironmentError as e:
			if e.errno != errno.EACCES:
				raise
			del e
			raise PermissionDenied(mypath)
		ftype = []
		for x in fpaths:
			try:
				if followSymlinks:
					pathstat = os.stat(mypath+"/"+x)
				else:
					pathstat = os.lstat(mypath+"/"+x)

				if stat.S_ISREG(pathstat[stat.ST_MODE]):
					ftype.append(0)
				elif stat.S_ISDIR(pathstat[stat.ST_MODE]):
					ftype.append(1)
				elif stat.S_ISLNK(pathstat[stat.ST_MODE]):
					ftype.append(2)
				else:
					ftype.append(3)
			except (IOError, OSError):
				ftype.append(3)

	if ignorelist or ignorecvs:
		ret_list = []
		ret_ftype = []
		for file_path, file_type in zip(fpaths, ftype):
			if file_path in ignorelist:
				pass
			elif ignorecvs:
				if file_path[:2] != ".#" and \
					not (file_type == 1 and file_path in VCS_DIRS):
					ret_list.append(file_path)
					ret_ftype.append(file_type)
	else:
		ret_list = fpaths
		ret_ftype = ftype

	return ret_list, ret_ftype

	def _scan_cat(self, cat):
		for repo in self._repo_list:
			cat_dir = repo.location + "/" + cat
			try:
				pkg_list = os.listdir(cat_dir)
			except OSError as e:
				if e.errno not in (errno.ENOTDIR, errno.ENOENT, errno.ESTALE):
					raise
				continue
			for p in pkg_list:
				if os.path.isdir(cat_dir + "/" + p):
					self._items[cat + "/" + p].append(repo)
		self._scanned_cats.add(cat)

		def modify_files(dir_path):
			for name in os.listdir(dir_path):
				path = os.path.join(dir_path, name)
				st = os.lstat(path)
				if stat.S_ISREG(st.st_mode):
					with io.open(path, mode='a',
						encoding=_encodings["stdio"]) as f:
						f.write("modified at %d\n" % time.time())
				elif stat.S_ISLNK(st.st_mode):
					old_dest = os.readlink(path)
					os.unlink(path)
					os.symlink(old_dest +
						" modified at %d" % time.time(), path)

def new_protect_filename(mydest, newmd5=None, force=False):
	"""Resolves a config-protect filename for merging, optionally
	using the last filename if the md5 matches. If force is True,
	then a new filename will be generated even if mydest does not
	exist yet.
	(dest,md5) ==> 'string'            --- path_to_target_filename
	(dest)     ==> ('next', 'highest') --- next_target and most-recent_target
	"""

	# config protection filename format:
	# ._cfg0000_foo
	# 0123456789012

	os = _os_merge

	prot_num = -1
	last_pfile = ""

	if not force and \
		not os.path.exists(mydest):
		return mydest

	real_filename = os.path.basename(mydest)
	real_dirname  = os.path.dirname(mydest)
	for pfile in os.listdir(real_dirname):
		if pfile[0:5] != "._cfg":
			continue
		if pfile[10:] != real_filename:
			continue
		try:
			new_prot_num = int(pfile[5:9])
			if new_prot_num > prot_num:
				prot_num = new_prot_num
				last_pfile = pfile
		except ValueError:
			continue
	prot_num = prot_num + 1

	new_pfile = normalize_path(os.path.join(real_dirname,
		"._cfg" + str(prot_num).zfill(4) + "_" + real_filename))
	old_pfile = normalize_path(os.path.join(real_dirname, last_pfile))
	if last_pfile and newmd5:
		try:
			last_pfile_md5 = portage.checksum._perform_md5_merge(old_pfile)
		except FileNotFound:
			# The file suddenly disappeared or it's a broken symlink.
			pass
		else:
			if last_pfile_md5 == newmd5:
				return old_pfile
	return new_pfile

	def AddPackagesInDir(path):
		""" Given a list of dirs, add any packages in it """
		ret = []
		pkgdirs = os.listdir(path)
		for d in pkgdirs:
			if d == 'CVS' or d.startswith('.'):
				continue
			p = os.path.join(path, d)

			if os.path.isdir(p):
				cat_pkg_dir = os.path.join(*p.split(os.path.sep)[-2:])
				logging.debug('adding %s to scanlist' % cat_pkg_dir)
				ret.append(cat_pkg_dir)
		return ret

def _calc_changelog(ebuildpath, current, next):
    if ebuildpath == None or not os.path.exists(ebuildpath):
        return []
    current = "-".join(catpkgsplit(current)[1:])
    if current.endswith("-r0"):
        current = current[:-3]
    next = "-".join(catpkgsplit(next)[1:])
    if next.endswith("-r0"):
        next = next[:-3]

    changelogdir = os.path.dirname(ebuildpath)
    changelogs = ["ChangeLog"]
    # ChangeLog-YYYY (see bug #389611)
    changelogs.extend(sorted((fn for fn in os.listdir(changelogdir) if fn.startswith("ChangeLog-")), reverse=True))

    divisions = []
    found_current = False
    for fn in changelogs:
        changelogpath = os.path.join(changelogdir, fn)
        try:
            with io.open(
                _unicode_encode(changelogpath, encoding=_encodings["fs"], errors="strict"),
                mode="r",
                encoding=_encodings["repo.content"],
                errors="replace",
            ) as f:
                changelog = f.read()
        except EnvironmentError:
            return []
        for node in _find_changelog_tags(changelog):
            if node[0] == current:
                found_current = True
                break
            else:
                divisions.append(node)
        if found_current:
            break

    if not found_current:
        return []

        # print 'XX from',current,'to',next
        # for div,text in divisions: print 'XX',div
        # skip entries for all revisions above the one we are about to emerge
    for i in range(len(divisions)):
        if divisions[i][0] == next:
            divisions = divisions[i:]
            break

    return divisions

	def __iter__(self):
		"""generator for walking the dir struct"""
		dirs = [self.location]
		len_base = len(self.location)
		while len(dirs):
			for l in os.listdir(dirs[0]):
				if l.endswith(".cpickle"):
					continue
				p = os.path.join(dirs[0],l)
				st = os.lstat(p)
				if stat.S_ISDIR(st.st_mode):
					dirs.append(p)
					continue
				yield p[len_base+1:]
			dirs.pop(0)

	def _scan(self, onProgress=None):
		"""
		Scan the file system for failed merges and return any found.

		@param onProgress: function to call for updating progress
		@type onProgress: Function
		@rtype: dict
		@return: dictionary of packages that failed to merges
		"""
		failed_pkgs = {}
		for cat in os.listdir(self._vardb_path):
			pkgs_path = os.path.join(self._vardb_path, cat)
			if not os.path.isdir(pkgs_path):
				continue
			pkgs = os.listdir(pkgs_path)
			maxval = len(pkgs)
			for i, pkg in enumerate(pkgs):
				if onProgress:
					onProgress(maxval, i+1)
				if MERGING_IDENTIFIER in pkg:
					mtime = int(os.stat(os.path.join(pkgs_path, pkg)).st_mtime)
					pkg = os.path.join(cat, pkg)
					failed_pkgs[pkg] = mtime
		return failed_pkgs

	def assertExists(self, path):
		"""Make sure |path| exists"""
		if not os.path.exists(path):
			msg = ['path is missing: %s' % (path,)]
			while path != '/':
				path = os.path.dirname(path)
				if not path:
					# If we're given something like "foo", abort once we get to "".
					break
				result = os.path.exists(path)
				msg.append('\tos.path.exists(%s): %s' % (path, result))
				if result:
					msg.append('\tcontents: %r' % os.listdir(path))
					break
			raise self.failureException('\n'.join(msg))

def fixdbentries(update_iter, dbdir):
	"""Performs update commands which result in search and replace operations
	for each of the files in dbdir (excluding CONTENTS and environment.bz2).
	Returns True when actual modifications are necessary and False otherwise."""
	mydata = {}
	for myfile in [f for f in os.listdir(dbdir) if f not in ignored_dbentries]:
		file_path = os.path.join(dbdir, myfile)
		mydata[myfile] = codecs.open(_unicode_encode(file_path,
			encoding=_encodings['fs'], errors='strict'),
			mode='r', encoding=_encodings['repo.content'],
			errors='replace').read()
	updated_items = update_dbentries(update_iter, mydata)
	for myfile, mycontent in updated_items.items():
		file_path = os.path.join(dbdir, myfile)
		write_atomic(file_path, mycontent, encoding=_encodings['repo.content'])
	return len(updated_items) > 0

def collect_binaries_from_dir(dirs, mask, logger):
	''' Collects all binaries from specified list of directories.
		mask is list of pathes, that are ommited in scanning,
		can be eighter single file or entire directory
		Returns list of binaries
	'''

	# contains list of directories found
	# allows us to reduce number of fnc calls
	found_directories = set()
	found_files = set()

	for _dir in dirs:
		if _dir in mask:
			continue

		try:
			for _listing in os.listdir(_dir):
				listing = os.path.join(_dir, _listing)
				if listing in mask or _listing in mask:
					continue

				if os.path.isdir(listing):
					if os.path.islink(listing):
						#we do not want scan symlink-directories
						pass
					else:
						found_directories.add(listing)
				elif os.path.isfile(listing):
					# we're looking for binaries
					# and with binaries we do not need links
					# thus we can optimize a bit
					if not os.path.islink(listing):
						prv = os.stat(listing)[stat.ST_MODE]
						if prv & stat.S_IXUSR == stat.S_IXUSR or \
								prv & stat.S_IXGRP == stat.S_IXGRP or \
								prv & stat.S_IXOTH == stat.S_IXOTH:
							found_files.add(listing)
		except Exception as ex:
			logger.debug('\t' +
				yellow('Exception during binaries collecting: '+
				blue('%s') %str(ex)))

	if found_directories:
		found_files.update(collect_binaries_from_dir(found_directories, mask, logger))

	return found_files