Python os.umask函数代码示例

	def _ensure_dirs(self, path=None):
		"""with path!=None, ensure beyond self.location.  otherwise, ensure self.location"""
		if path:
			path = os.path.dirname(path)
			base = self.location
		else:
			path = self.location
			base='/'

		for dir in path.lstrip(os.path.sep).rstrip(os.path.sep).split(os.path.sep):
			base = os.path.join(base,dir)
			if not os.path.exists(base):
				if self._perms != -1:
					um = os.umask(0)
				try:
					perms = self._perms
					if perms == -1:
						perms = 0
					perms |= 0o755
					os.mkdir(base, perms)
					if self._gid != -1:
						os.chown(base, -1, self._gid)
				finally:
					if self._perms != -1:
						os.umask(um)

def emerge_main(args=None, build_dict=None):
	"""
	@param args: command arguments (default: sys.argv[1:])
	@type args: list
	@param build_dict: info of the build_job
	@type build_dict: dict
	"""
	if args is None:
		args = sys.argv[1:]

	if build_dict is None:
		build_dict = {}

	# Disable color until we're sure that it should be enabled (after
	# EMERGE_DEFAULT_OPTS has been parsed).
	portage.output.havecolor = 0

	# This first pass is just for options that need to be known as early as
	# possible, such as --config-root.  They will be parsed again later,
	# together with EMERGE_DEFAULT_OPTS (which may vary depending on the
	# the value of --config-root).
	myaction, myopts, myfiles = parse_opts(args, silent=True)
	if "--debug" in myopts:
		os.environ["PORTAGE_DEBUG"] = "1"
	if "--config-root" in myopts:
		os.environ["PORTAGE_CONFIGROOT"] = myopts["--config-root"]
	if "--root" in myopts:
		os.environ["ROOT"] = myopts["--root"]
	if "--accept-properties" in myopts:
		os.environ["ACCEPT_PROPERTIES"] = myopts["--accept-properties"]

	# optimize --help (no need to load config / EMERGE_DEFAULT_OPTS)
	if myaction == "help":
		emerge_help()
		return os.EX_OK
	elif myaction == "moo":
		print(COWSAY_MOO % platform.system())
		return os.EX_OK

	# Portage needs to ensure a sane umask for the files it creates.
	os.umask(0o22)
	if myaction == "sync":
		portage._sync_disabled_warnings = True
	settings, trees, mtimedb = load_emerge_config()
	rval = profile_check(trees, myaction)
	if rval != os.EX_OK:
		return rval

	tmpcmdline = []
	if "--ignore-default-opts" not in myopts:
		tmpcmdline.extend(settings["EMERGE_DEFAULT_OPTS"].split())
	tmpcmdline.extend(args)
	myaction, myopts, myfiles = parse_opts(tmpcmdline)

	return run_action(settings, trees, mtimedb, myaction, myopts, myfiles, build_dict,
		gc_locals=locals().clear)

	def __init__(self, settings, logger):
		self.settings = settings
		self.logger = logger
		# Similar to emerge, sync needs a default umask so that created
		# files have sane permissions.
		os.umask(0o22)

		self.module_controller = portage.sync.module_controller
		self.module_names = self.module_controller.module_names
		self.hooks = {}
		for _dir in ["repo.postsync.d", "postsync.d"]:
			postsync_dir = os.path.join(self.settings["PORTAGE_CONFIGROOT"],
				portage.USER_CONFIG_PATH, _dir)
			hooks = OrderedDict()
			for filepath in util._recursive_file_list(postsync_dir):
				name = filepath.split(postsync_dir)[1].lstrip(os.sep)
				if os.access(filepath, os.X_OK):
					hooks[filepath] = name
				else:
					writemsg_level(" %s %s hook: '%s' is not executable\n"
						% (warn("*"), _dir, _unicode_decode(name),),
						level=logging.WARN, noiselevel=2)
			self.hooks[_dir] = hooks

def emaint_main(myargv):

	# Similar to emerge, emaint needs a default umask so that created
	# files (such as the world file) have sane permissions.
	os.umask(0o22)

	module_path = os.path.join(
		(os.path.dirname(
		os.path.realpath(__file__))), "modules"
		)
	module_controller = Modules(
		path=module_path,
		namepath="portage.emaint.modules")
	module_names = module_controller.module_names[:]
	module_names.insert(0, "all")


	parser = ArgumentParser(usage=usage(module_controller))
	# add default options
	parser_options = []
	for opt in DEFAULT_OPTIONS:
		parser_options.append(OptionItem(DEFAULT_OPTIONS[opt]))
	for mod in module_names[1:]:
		desc = module_controller.get_func_descriptions(mod)
		if desc:
			for opt in desc:
				parser_options.append(OptionItem(desc[opt]))
		desc = module_controller.get_opt_descriptions(mod)
		if desc:
			for opt in desc:
				parser_options.append(OptionItem(desc[opt]))
	for opt in parser_options:
		parser.add_argument(*opt.pargs, **opt.kwargs)

	options, args = parser.parse_known_args(args=myargv)

	if options.version:
		print(portage.VERSION)
		return os.EX_OK

	if len(args) != 1:
		parser.error("Incorrect number of arguments")
	if args[0] not in module_names:
		parser.error("%s target is not a known target" % args[0])

	check_opt = None
	func = status = long_action = None
	for opt in parser_options:
		if opt.long == '--check':
			# Default action
			check_opt = opt
		if opt.status and getattr(options, opt.target, False):
			if long_action is not None:
				parser.error("--%s and %s are exclusive options" %
					(long_action, opt.long))
			status = opt.status
			func = opt.func
			long_action = opt.long.lstrip('-')

	if long_action is None:
		#print("DEBUG: long_action is None: setting to 'check'")
		long_action = 'check'
		func = check_opt.func
		status = check_opt.status

	if args[0] == "all":
		tasks = []
		for m in module_names[1:]:
			#print("DEBUG: module: %s, functions: " % (m, str(module_controller.get_functions(m))))
			if long_action in module_controller.get_functions(m):
				tasks.append(module_controller.get_class(m))
	elif long_action in module_controller.get_functions(args[0]):
		tasks = [module_controller.get_class(args[0] )]
	else:
		portage.util.writemsg(
			"\nERROR: module '%s' does not have option '--%s'\n\n" %
			(args[0], long_action), noiselevel=-1)
		portage.util.writemsg(module_opts(module_controller, args[0]),
			noiselevel=-1)
		sys.exit(1)

	# need to pass the parser options dict to the modules
	# so they are available if needed.
	task_opts = options.__dict__
	task_opts['return-messages'] = True
	taskmaster = TaskHandler(callback=print_results, module_output=sys.stdout)
	taskmaster.run_tasks(tasks, func, status, options=task_opts)

def _exec(binary, mycommand, opt_name, fd_pipes, env, gid, groups, uid, umask,
	pre_exec):

	"""
	Execute a given binary with options
	
	@param binary: Name of program to execute
	@type binary: String
	@param mycommand: Options for program
	@type mycommand: String
	@param opt_name: Name of process (defaults to binary)
	@type opt_name: String
	@param fd_pipes: Mapping pipes to destination; { 0:0, 1:1, 2:2 }
	@type fd_pipes: Dictionary
	@param env: Key,Value mapping for Environmental Variables
	@type env: Dictionary
	@param gid: Group ID to run the process under
	@type gid: Integer
	@param groups: Groups the Process should be in.
	@type groups: Integer
	@param uid: User ID to run the process under
	@type uid: Integer
	@param umask: an int representing a unix umask (see man chmod for umask details)
	@type umask: Integer
	@param pre_exec: A function to be called with no arguments just prior to the exec call.
	@type pre_exec: callable
	@rtype: None
	@return: Never returns (calls os.execve)
	"""
	
	# If the process we're creating hasn't been given a name
	# assign it the name of the executable.
	if not opt_name:
		if binary is portage._python_interpreter:
			# NOTE: PyPy 1.7 will die due to "libary path not found" if argv[0]
			# does not contain the full path of the binary.
			opt_name = binary
		else:
			opt_name = os.path.basename(binary)

	# Set up the command's argument list.
	myargs = [opt_name]
	myargs.extend(mycommand[1:])

	# Use default signal handlers in order to avoid problems
	# killing subprocesses as reported in bug #353239.
	signal.signal(signal.SIGINT, signal.SIG_DFL)
	signal.signal(signal.SIGTERM, signal.SIG_DFL)

	# Quiet killing of subprocesses by SIGPIPE (see bug #309001).
	signal.signal(signal.SIGPIPE, signal.SIG_DFL)

	# Avoid issues triggered by inheritance of SIGQUIT handler from
	# the parent process (see bug #289486).
	signal.signal(signal.SIGQUIT, signal.SIG_DFL)

	_setup_pipes(fd_pipes)

	# Set requested process permissions.
	if gid:
		os.setgid(gid)
	if groups:
		os.setgroups(groups)
	if uid:
		os.setuid(uid)
	if umask:
		os.umask(umask)
	if pre_exec:
		pre_exec()

	# And switch to the new process.
	os.execve(binary, myargs, env)

    def pre_sync(self, repo):
        msg = ">>> Syncing repository '%s' into '%s'..." % (repo.name, repo.location)
        self.logger(self.xterm_titles, msg)
        writemsg_level(msg + "\n")
        try:
            st = os.stat(repo.location)
        except OSError:
            st = None

        self.usersync_uid = None
        spawn_kwargs = {}
        # Redirect command stderr to stdout, in order to prevent
        # spurious cron job emails (bug 566132).
        spawn_kwargs["fd_pipes"] = {0: sys.__stdin__.fileno(), 1: sys.__stdout__.fileno(), 2: sys.__stdout__.fileno()}
        spawn_kwargs["env"] = self.settings.environ()
        if repo.sync_user is not None:

            def get_sync_user_data(sync_user):
                user = None
                group = None
                home = None
                logname = None

                spl = sync_user.split(":", 1)
                if spl[0]:
                    username = spl[0]
                    try:
                        try:
                            pw = pwd.getpwnam(username)
                        except KeyError:
                            pw = pwd.getpwuid(int(username))
                    except (ValueError, KeyError):
                        writemsg("!!! User '%s' invalid or does not exist\n" % username, noiselevel=-1)
                        return (logname, user, group, home)
                    user = pw.pw_uid
                    group = pw.pw_gid
                    home = pw.pw_dir
                    logname = pw.pw_name

                if len(spl) > 1:
                    groupname = spl[1]
                    try:
                        try:
                            gp = grp.getgrnam(groupname)
                        except KeyError:
                            pw = grp.getgrgid(int(groupname))
                    except (ValueError, KeyError):
                        writemsg("!!! Group '%s' invalid or does not exist\n" % groupname, noiselevel=-1)
                        return (logname, user, group, home)

                    group = gp.gr_gid

                return (logname, user, group, home)

                # user or user:group

            (logname, uid, gid, home) = get_sync_user_data(repo.sync_user)
            if uid is not None:
                spawn_kwargs["uid"] = uid
                self.usersync_uid = uid
            if gid is not None:
                spawn_kwargs["gid"] = gid
                spawn_kwargs["groups"] = [gid]
            if home is not None:
                spawn_kwargs["env"]["HOME"] = home
            if logname is not None:
                spawn_kwargs["env"]["LOGNAME"] = logname

        if st is None:
            perms = {"mode": 0o755}
            # respect sync-user if set
            if "umask" in spawn_kwargs:
                perms["mode"] &= ~spawn_kwargs["umask"]
            if "uid" in spawn_kwargs:
                perms["uid"] = spawn_kwargs["uid"]
            if "gid" in spawn_kwargs:
                perms["gid"] = spawn_kwargs["gid"]

            portage.util.ensure_dirs(repo.location, **perms)
            st = os.stat(repo.location)

        if (
            repo.sync_user is None
            and "usersync" in self.settings.features
            and portage.data.secpass >= 2
            and (st.st_uid != os.getuid() and st.st_mode & 0o700 or st.st_gid != os.getgid() and st.st_mode & 0o070)
        ):
            try:
                pw = pwd.getpwuid(st.st_uid)
            except KeyError:
                pass
            else:
                # Drop privileges when syncing, in order to match
                # existing uid/gid settings.
                self.usersync_uid = st.st_uid
                spawn_kwargs["uid"] = st.st_uid
                spawn_kwargs["gid"] = st.st_gid
                spawn_kwargs["groups"] = [st.st_gid]
                spawn_kwargs["env"]["HOME"] = pw.pw_dir
                spawn_kwargs["env"]["LOGNAME"] = pw.pw_name
#.........这里部分代码省略.........

def _exec(binary, mycommand, opt_name, fd_pipes, env, gid, groups, uid, umask,
	pre_exec):

	"""
	Execute a given binary with options
	
	@param binary: Name of program to execute
	@type binary: String
	@param mycommand: Options for program
	@type mycommand: String
	@param opt_name: Name of process (defaults to binary)
	@type opt_name: String
	@param fd_pipes: Mapping pipes to destination; { 0:0, 1:1, 2:2 }
	@type fd_pipes: Dictionary
	@param env: Key,Value mapping for Environmental Variables
	@type env: Dictionary
	@param gid: Group ID to run the process under
	@type gid: Integer
	@param groups: Groups the Process should be in.
	@type groups: Integer
	@param uid: User ID to run the process under
	@type uid: Integer
	@param umask: an int representing a unix umask (see man chmod for umask details)
	@type umask: Integer
	@param pre_exec: A function to be called with no arguments just prior to the exec call.
	@type pre_exec: callable
	@rtype: None
	@returns: Never returns (calls os.execve)
	"""
	
	# If the process we're creating hasn't been given a name
	# assign it the name of the executable.
	if not opt_name:
		opt_name = os.path.basename(binary)

	# Set up the command's argument list.
	myargs = [opt_name]
	myargs.extend(mycommand[1:])

	# Set up the command's pipes.
	my_fds = {}
	# To protect from cases where direct assignment could
	# clobber needed fds ({1:2, 2:1}) we first dupe the fds
	# into unused fds.
	for fd in fd_pipes:
		my_fds[fd] = os.dup(fd_pipes[fd])
	# Then assign them to what they should be.
	for fd in my_fds:
		os.dup2(my_fds[fd], fd)
	# Then close _all_ fds that haven't been explictly
	# requested to be kept open.
	for fd in get_open_fds():
		if fd not in my_fds:
			try:
				os.close(fd)
			except OSError:
				pass

	# Set requested process permissions.
	if gid:
		os.setgid(gid)
	if groups:
		os.setgroups(groups)
	if uid:
		os.setuid(uid)
	if umask:
		os.umask(umask)
	if pre_exec:
		pre_exec()

	# And switch to the new process.
	os.execve(binary, myargs, env)

def lockfile(mypath, wantnewlockfile=0, unlinkfile=0,
	waiting_msg=None, flags=0):
	"""
	If wantnewlockfile is True then this creates a lockfile in the parent
	directory as the file: '.' + basename + '.portage_lockfile'.
	"""

	if not mypath:
		raise InvalidData(_("Empty path given"))

	# Since Python 3.4, chown requires int type (no proxies).
	portage_gid = int(portage.data.portage_gid)

	# Support for file object or integer file descriptor parameters is
	# deprecated due to ambiguity in whether or not it's safe to close
	# the file descriptor, making it prone to "Bad file descriptor" errors
	# or file descriptor leaks.
	if isinstance(mypath, basestring) and mypath[-1] == '/':
		mypath = mypath[:-1]

	lockfilename_path = mypath
	if hasattr(mypath, 'fileno'):
		warnings.warn("portage.locks.lockfile() support for "
			"file object parameters is deprecated. Use a file path instead.",
			DeprecationWarning, stacklevel=2)
		lockfilename_path = getattr(mypath, 'name', None)
		mypath = mypath.fileno()
	if isinstance(mypath, int):
		warnings.warn("portage.locks.lockfile() support for integer file "
			"descriptor parameters is deprecated. Use a file path instead.",
			DeprecationWarning, stacklevel=2)
		lockfilename    = mypath
		wantnewlockfile = 0
		unlinkfile      = 0
	elif wantnewlockfile:
		base, tail = os.path.split(mypath)
		lockfilename = os.path.join(base, "." + tail + ".portage_lockfile")
		lockfilename_path = lockfilename
		unlinkfile   = 1
	else:
		lockfilename = mypath

	if isinstance(mypath, basestring):
		if not os.path.exists(os.path.dirname(mypath)):
			raise DirectoryNotFound(os.path.dirname(mypath))
		preexisting = os.path.exists(lockfilename)
		old_mask = os.umask(000)
		try:
			try:
				myfd = os.open(lockfilename, os.O_CREAT|os.O_RDWR, 0o660)
			except OSError as e:
				func_call = "open('%s')" % lockfilename
				if e.errno == OperationNotPermitted.errno:
					raise OperationNotPermitted(func_call)
				elif e.errno == PermissionDenied.errno:
					raise PermissionDenied(func_call)
				elif e.errno == ReadOnlyFileSystem.errno:
					raise ReadOnlyFileSystem(func_call)
				else:
					raise

			if not preexisting:
				try:
					if os.stat(lockfilename).st_gid != portage_gid:
						os.chown(lockfilename, -1, portage_gid)
				except OSError as e:
					if e.errno in (errno.ENOENT, errno.ESTALE):
						return lockfile(mypath,
							wantnewlockfile=wantnewlockfile,
							unlinkfile=unlinkfile, waiting_msg=waiting_msg,
							flags=flags)
					else:
						writemsg("%s: chown('%s', -1, %d)\n" % \
							(e, lockfilename, portage_gid), noiselevel=-1)
						writemsg(_("Cannot chown a lockfile: '%s'\n") % \
							lockfilename, noiselevel=-1)
						writemsg(_("Group IDs of current user: %s\n") % \
							" ".join(str(n) for n in os.getgroups()),
							noiselevel=-1)
		finally:
			os.umask(old_mask)

	elif isinstance(mypath, int):
		myfd = mypath

	else:
		raise ValueError(_("Unknown type passed in '%s': '%s'") % \
			(type(mypath), mypath))

	# try for a non-blocking lock, if it's held, throw a message
	# we're waiting on lockfile and use a blocking attempt.
	locking_method = portage._eintr_func_wrapper(_default_lock_fn)
	try:
		if "__PORTAGE_TEST_HARDLINK_LOCKS" in os.environ:
			raise IOError(errno.ENOSYS, "Function not implemented")
		locking_method(myfd, fcntl.LOCK_EX|fcntl.LOCK_NB)
	except IOError as e:
		if not hasattr(e, "errno"):
			raise
		if e.errno in (errno.EACCES, errno.EAGAIN, errno.ENOLCK):
#.........这里部分代码省略.........

from repoman.argparser import parse_args
from repoman.qa_data import QAData
from repoman.qa_data import format_qa_output, format_qa_output_column
from repoman.repos import RepoSettings
from repoman.scanner import Scanner
from repoman import utilities
from repoman.modules.vcs.settings import VCSSettings
from repoman import VERSION

if sys.hexversion >= 0x3000000:
	basestring = str

bad = create_color_func("BAD")

# A sane umask is needed for files that portage creates.
os.umask(0o22)

LOGLEVEL = logging.WARNING
portage.util.initialize_logger(LOGLEVEL)

VALID_VERSIONS = [1,]

def repoman_main(argv):
	config_root = os.environ.get("PORTAGE_CONFIGROOT")
	repoman_settings = portage.config(config_root=config_root, local_config=False)
	repoman_settings.valid_versions = VALID_VERSIONS

	if repoman_settings.get("NOCOLOR", "").lower() in ("yes", "true") or \
		repoman_settings.get('TERM') == 'dumb' or \
		not sys.stdout.isatty():
		nocolor()

def _exec(binary, mycommand, opt_name, fd_pipes, env, gid, groups, uid, umask,
	pre_exec, close_fds, unshare_net, unshare_ipc, cgroup):

	"""
	Execute a given binary with options
	
	@param binary: Name of program to execute
	@type binary: String
	@param mycommand: Options for program
	@type mycommand: String
	@param opt_name: Name of process (defaults to binary)
	@type opt_name: String
	@param fd_pipes: Mapping pipes to destination; { 0:0, 1:1, 2:2 }
	@type fd_pipes: Dictionary
	@param env: Key,Value mapping for Environmental Variables
	@type env: Dictionary
	@param gid: Group ID to run the process under
	@type gid: Integer
	@param groups: Groups the Process should be in.
	@type groups: Integer
	@param uid: User ID to run the process under
	@type uid: Integer
	@param umask: an int representing a unix umask (see man chmod for umask details)
	@type umask: Integer
	@param pre_exec: A function to be called with no arguments just prior to the exec call.
	@type pre_exec: callable
	@param unshare_net: If True, networking will be unshared from the spawned process
	@type unshare_net: Boolean
	@param unshare_ipc: If True, IPC will be unshared from the spawned process
	@type unshare_ipc: Boolean
	@param cgroup: CGroup path to bind the process to
	@type cgroup: String
	@rtype: None
	@return: Never returns (calls os.execve)
	"""

	# If the process we're creating hasn't been given a name
	# assign it the name of the executable.
	if not opt_name:
		if binary is portage._python_interpreter:
			# NOTE: PyPy 1.7 will die due to "libary path not found" if argv[0]
			# does not contain the full path of the binary.
			opt_name = binary
		else:
			opt_name = os.path.basename(binary)

	# Set up the command's argument list.
	myargs = [opt_name]
	myargs.extend(mycommand[1:])

	# Avoid a potential UnicodeEncodeError from os.execve().
	myargs = [_unicode_encode(x, encoding=_encodings['fs'],
		errors='strict') for x in myargs]

	# Use default signal handlers in order to avoid problems
	# killing subprocesses as reported in bug #353239.
	signal.signal(signal.SIGINT, signal.SIG_DFL)
	signal.signal(signal.SIGTERM, signal.SIG_DFL)

	# Quiet killing of subprocesses by SIGPIPE (see bug #309001).
	signal.signal(signal.SIGPIPE, signal.SIG_DFL)

	# Avoid issues triggered by inheritance of SIGQUIT handler from
	# the parent process (see bug #289486).
	signal.signal(signal.SIGQUIT, signal.SIG_DFL)

	_setup_pipes(fd_pipes, close_fds=close_fds, inheritable=True)

	# Add to cgroup
	# it's better to do it from the child since we can guarantee
	# it is done before we start forking children
	if cgroup:
		with open(os.path.join(cgroup, 'cgroup.procs'), 'a') as f:
			f.write('%d\n' % os.getpid())

	# Unshare (while still uid==0)
	if unshare_net or unshare_ipc:
		filename = find_library("c")
		if filename is not None:
			libc = LoadLibrary(filename)
			if libc is not None:
				CLONE_NEWIPC = 0x08000000
				CLONE_NEWNET = 0x40000000

				flags = 0
				if unshare_net:
					flags |= CLONE_NEWNET
				if unshare_ipc:
					flags |= CLONE_NEWIPC

				try:
					if libc.unshare(flags) != 0:
						writemsg("Unable to unshare: %s\n" % (
							errno.errorcode.get(ctypes.get_errno(), '?')),
							noiselevel=-1)
					else:
						if unshare_net:
							# 'up' the loopback
							IFF_UP = 0x1
							ifreq = struct.pack('16sh', b'lo', IFF_UP)
#.........这里部分代码省略.........

def _exec(binary, mycommand, opt_name, fd_pipes,
	env, gid, groups, uid, umask, cwd,
	pre_exec, close_fds, unshare_net, unshare_ipc, unshare_mount, unshare_pid,
	unshare_flags, cgroup):

	"""
	Execute a given binary with options
	
	@param binary: Name of program to execute
	@type binary: String
	@param mycommand: Options for program
	@type mycommand: String
	@param opt_name: Name of process (defaults to binary)
	@type opt_name: String
	@param fd_pipes: Mapping pipes to destination; { 0:0, 1:1, 2:2 }
	@type fd_pipes: Dictionary
	@param env: Key,Value mapping for Environmental Variables
	@type env: Dictionary
	@param gid: Group ID to run the process under
	@type gid: Integer
	@param groups: Groups the Process should be in.
	@type groups: List
	@param uid: User ID to run the process under
	@type uid: Integer
	@param umask: an int representing a unix umask (see man chmod for umask details)
	@type umask: Integer
	@param cwd: Current working directory
	@type cwd: String
	@param pre_exec: A function to be called with no arguments just prior to the exec call.
	@type pre_exec: callable
	@param unshare_net: If True, networking will be unshared from the spawned process
	@type unshare_net: Boolean
	@param unshare_ipc: If True, IPC will be unshared from the spawned process
	@type unshare_ipc: Boolean
	@param unshare_mount: If True, mount namespace will be unshared and mounts will
		be private to the namespace
	@type unshare_mount: Boolean
	@param unshare_pid: If True, PID ns will be unshared from the spawned process
	@type unshare_pid: Boolean
	@param unshare_flags: Flags for the unshare(2) function
	@type unshare_flags: Integer
	@param cgroup: CGroup path to bind the process to
	@type cgroup: String
	@rtype: None
	@return: Never returns (calls os.execve)
	"""

	# If the process we're creating hasn't been given a name
	# assign it the name of the executable.
	if not opt_name:
		if binary is portage._python_interpreter:
			# NOTE: PyPy 1.7 will die due to "libary path not found" if argv[0]
			# does not contain the full path of the binary.
			opt_name = binary
		else:
			opt_name = os.path.basename(binary)

	# Set up the command's argument list.
	myargs = [opt_name]
	myargs.extend(mycommand[1:])

	# Avoid a potential UnicodeEncodeError from os.execve().
	myargs = [_unicode_encode(x, encoding=_encodings['fs'],
		errors='strict') for x in myargs]

	# Use default signal handlers in order to avoid problems
	# killing subprocesses as reported in bug #353239.
	signal.signal(signal.SIGINT, signal.SIG_DFL)
	signal.signal(signal.SIGTERM, signal.SIG_DFL)

	# Unregister SIGCHLD handler and wakeup_fd for the parent
	# process's event loop (bug 655656).
	signal.signal(signal.SIGCHLD, signal.SIG_DFL)
	try:
		wakeup_fd = signal.set_wakeup_fd(-1)
		if wakeup_fd > 0:
			os.close(wakeup_fd)
	except (ValueError, OSError):
		pass

	# Quiet killing of subprocesses by SIGPIPE (see bug #309001).
	signal.signal(signal.SIGPIPE, signal.SIG_DFL)

	# Avoid issues triggered by inheritance of SIGQUIT handler from
	# the parent process (see bug #289486).
	signal.signal(signal.SIGQUIT, signal.SIG_DFL)

	_setup_pipes(fd_pipes, close_fds=close_fds, inheritable=True)

	# Add to cgroup
	# it's better to do it from the child since we can guarantee
	# it is done before we start forking children
	if cgroup:
		with open(os.path.join(cgroup, 'cgroup.procs'), 'a') as f:
			f.write('%d\n' % os.getpid())

	# Unshare (while still uid==0)
	if unshare_net or unshare_ipc or unshare_mount or unshare_pid:
		filename = find_library("c")
		if filename is not None:
#.........这里部分代码省略.........

	def pre_sync(self, repo):
		self.settings, self.trees, self.mtimedb = self.emerge_config
		self.xterm_titles = "notitles" not in self.settings.features
		msg = ">>> Synchronization of repository '%s' located in '%s'..." \
			% (repo.name, repo.location)
		self.logger(self.xterm_titles, msg)
		writemsg_level(msg + "\n")
		try:
			st = os.stat(repo.location)
		except OSError:
			st = None

		self.usersync_uid = None
		spawn_kwargs = {}
		spawn_kwargs["env"] = self.settings.environ()
		if repo.sync_user is not None:
			def get_sync_user_data(sync_user):
				user = None
				group = None
				home = None

				spl = sync_user.split(':', 1)
				if spl[0]:
					username = spl[0]
					try:
						try:
							pw = pwd.getpwnam(username)
						except KeyError:
							pw = pwd.getpwuid(int(username))
					except (ValueError, KeyError):
						writemsg("!!! User '%s' invalid or does not exist\n"
								% username, noiselevel=-1)
						return (user, group, home)
					user = pw.pw_uid
					group = pw.pw_gid
					home = pw.pw_dir

				if len(spl) > 1:
					groupname = spl[1]
					try:
						try:
							gp = grp.getgrnam(groupname)
						except KeyError:
							pw = grp.getgrgid(int(groupname))
					except (ValueError, KeyError):
						writemsg("!!! Group '%s' invalid or does not exist\n"
								% groupname, noiselevel=-1)
						return (user, group, home)

					group = gp.gr_gid

				return (user, group, home)

			# user or user:group
			(uid, gid, home) = get_sync_user_data(repo.sync_user)
			if uid is not None:
				spawn_kwargs["uid"] = uid
				self.usersync_uid = uid
			if gid is not None:
				spawn_kwargs["gid"] = gid
				spawn_kwargs["groups"] = [gid]
			if home is not None:
				spawn_kwargs["env"]["HOME"] = home

		if st is None:
			perms = {'mode': 0o755}
			# respect sync-user if set
			if 'umask' in spawn_kwargs:
				perms['mode'] &= ~spawn_kwargs['umask']
			if 'uid' in spawn_kwargs:
				perms['uid'] = spawn_kwargs['uid']
			if 'gid' in spawn_kwargs:
				perms['gid'] = spawn_kwargs['gid']

			writemsg_level(">>> '%s' not found, creating it."
				% _unicode_decode(repo.location))
			portage.util.ensure_dirs(repo.location, **perms)
			st = os.stat(repo.location)

		if (repo.sync_user is None and
			'usersync' in self.settings.features and
			portage.data.secpass >= 2 and
			(st.st_uid != os.getuid() and st.st_mode & 0o700 or
			st.st_gid != os.getgid() and st.st_mode & 0o070)):
			try:
				homedir = pwd.getpwuid(st.st_uid).pw_dir
			except KeyError:
				pass
			else:
				# Drop privileges when syncing, in order to match
				# existing uid/gid settings.
				self.usersync_uid = st.st_uid
				spawn_kwargs["uid"]    = st.st_uid
				spawn_kwargs["gid"]    = st.st_gid
				spawn_kwargs["groups"] = [st.st_gid]
				spawn_kwargs["env"]["HOME"] = homedir
				umask = 0o002
				if not st.st_mode & 0o020:
					umask = umask | 0o020
				spawn_kwargs["umask"] = umask
#.........这里部分代码省略.........

def _get_legacy_global(name):
	constructed = portage._legacy_globals_constructed
	if name in constructed:
		return getattr(portage, name)

	if name == 'portdb':
		portage.portdb = portage.db[portage.root]["porttree"].dbapi
		constructed.add(name)
		return getattr(portage, name)

	elif name in ('mtimedb', 'mtimedbfile'):
		portage.mtimedbfile = os.path.join(portage.settings['EROOT'],
			CACHE_PATH, "mtimedb")
		constructed.add('mtimedbfile')
		portage.mtimedb = portage.MtimeDB(portage.mtimedbfile)
		constructed.add('mtimedb')
		return getattr(portage, name)

	# Portage needs to ensure a sane umask for the files it creates.
	os.umask(0o22)

	kwargs = {}
	for k, envvar in (("config_root", "PORTAGE_CONFIGROOT"),
			("target_root", "ROOT"), ("eprefix", "EPREFIX")):
		kwargs[k] = os.environ.get(envvar)

	portage._initializing_globals = True
	portage.db = portage.create_trees(**kwargs)
	constructed.add('db')
	del portage._initializing_globals

	settings = portage.db[portage.db._target_eroot]["vartree"].settings

	portage.settings = settings
	constructed.add('settings')

	# Since portage.db now uses EROOT for keys instead of ROOT, we make
	# portage.root refer to EROOT such that it continues to work as a key.
	portage.root = portage.db._target_eroot
	constructed.add('root')

	# COMPATIBILITY
	# These attributes should not be used within
	# Portage under any circumstances.

	portage.archlist = settings.archlist()
	constructed.add('archlist')

	portage.features = settings.features
	constructed.add('features')

	portage.groups = settings.get("ACCEPT_KEYWORDS", "").split()
	constructed.add('groups')

	portage.pkglines = settings.packages
	constructed.add('pkglines')

	portage.selinux_enabled = settings.selinux_enabled()
	constructed.add('selinux_enabled')

	portage.thirdpartymirrors = settings.thirdpartymirrors()
	constructed.add('thirdpartymirrors')

	profiledir = os.path.join(settings["PORTAGE_CONFIGROOT"], PROFILE_PATH)
	if not os.path.isdir(profiledir):
		profiledir = None
	portage.profiledir = profiledir
	constructed.add('profiledir')

	return getattr(portage, name)

def emerge_main(args=None):
	"""
	@param args: command arguments (default: sys.argv[1:])
	@type args: list
	"""
	if args is None:
		args = sys.argv[1:]

	args = portage._decode_argv(args)

	# Use system locale.
	locale.setlocale(locale.LC_ALL, '')

	# Disable color until we're sure that it should be enabled (after
	# EMERGE_DEFAULT_OPTS has been parsed).
	portage.output.havecolor = 0

	# This first pass is just for options that need to be known as early as
	# possible, such as --config-root.  They will be parsed again later,
	# together with EMERGE_DEFAULT_OPTS (which may vary depending on the
	# the value of --config-root).
	myaction, myopts, myfiles = parse_opts(args, silent=True)
	if "--debug" in myopts:
		os.environ["PORTAGE_DEBUG"] = "1"
	if "--config-root" in myopts:
		os.environ["PORTAGE_CONFIGROOT"] = myopts["--config-root"]
	if "--root" in myopts:
		os.environ["ROOT"] = myopts["--root"]
	if "--prefix" in myopts:
		os.environ["EPREFIX"] = myopts["--prefix"]
	if "--accept-properties" in myopts:
		os.environ["ACCEPT_PROPERTIES"] = myopts["--accept-properties"]
	if "--accept-restrict" in myopts:
		os.environ["ACCEPT_RESTRICT"] = myopts["--accept-restrict"]

	# optimize --help (no need to load config / EMERGE_DEFAULT_OPTS)
	if myaction == "help":
		emerge_help()
		return os.EX_OK
	elif myaction == "moo":
		print(COWSAY_MOO % platform.system())
		return os.EX_OK

	# Portage needs to ensure a sane umask for the files it creates.
	os.umask(0o22)
	if myaction == "sync":
		portage._sync_mode = True
	emerge_config = load_emerge_config(
		action=myaction, args=myfiles, opts=myopts)
	rval = profile_check(emerge_config.trees, emerge_config.action)
	if rval != os.EX_OK:
		return rval

	tmpcmdline = []
	if "--ignore-default-opts" not in myopts:
		tmpcmdline.extend(portage.util.shlex_split(
			emerge_config.target_config.settings.get(
			"EMERGE_DEFAULT_OPTS", "")))
	tmpcmdline.extend(args)
	emerge_config.action, emerge_config.opts, emerge_config.args = \
		parse_opts(tmpcmdline)

	try:
		return run_action(emerge_config)
	finally:
		# Call destructors for our portdbapi instances.
		for x in emerge_config.trees.values():
			if "porttree" in x.lazy_items:
				continue
			x["porttree"].dbapi.close_caches()

def emerge_main():
	global portage	# NFC why this is necessary now - genone
	portage._disable_legacy_globals()
	# Disable color until we're sure that it should be enabled (after
	# EMERGE_DEFAULT_OPTS has been parsed).
	portage.output.havecolor = 0
	# This first pass is just for options that need to be known as early as
	# possible, such as --config-root.  They will be parsed again later,
	# together with EMERGE_DEFAULT_OPTS (which may vary depending on the
	# the value of --config-root).
	myaction, myopts, myfiles = parse_opts(sys.argv[1:], silent=True)
	if "--debug" in myopts:
		os.environ["PORTAGE_DEBUG"] = "1"
	if "--config-root" in myopts:
		os.environ["PORTAGE_CONFIGROOT"] = myopts["--config-root"]
	if "--root" in myopts:
		os.environ["ROOT"] = myopts["--root"]
	if "--accept-properties" in myopts:
		os.environ["ACCEPT_PROPERTIES"] = myopts["--accept-properties"]

	# Portage needs to ensure a sane umask for the files it creates.
	os.umask(0o22)
	settings, trees, mtimedb = load_emerge_config()
	portdb = trees[settings["ROOT"]]["porttree"].dbapi
	rval = profile_check(trees, myaction)
	if rval != os.EX_OK:
		return rval

	if myaction not in ('help', 'info', 'version') and \
		_global_updates(trees, mtimedb["updates"]):
		mtimedb.commit()
		# Reload the whole config from scratch.
		settings, trees, mtimedb = load_emerge_config(trees=trees)
		portdb = trees[settings["ROOT"]]["porttree"].dbapi

	xterm_titles = "notitles" not in settings.features
	if xterm_titles:
		xtermTitle("emerge")

	tmpcmdline = []
	if "--ignore-default-opts" not in myopts:
		tmpcmdline.extend(settings["EMERGE_DEFAULT_OPTS"].split())
	tmpcmdline.extend(sys.argv[1:])
	myaction, myopts, myfiles = parse_opts(tmpcmdline)

	if "--digest" in myopts:
		os.environ["FEATURES"] = os.environ.get("FEATURES","") + " digest"
		# Reload the whole config from scratch so that the portdbapi internal
		# config is updated with new FEATURES.
		settings, trees, mtimedb = load_emerge_config(trees=trees)
		portdb = trees[settings["ROOT"]]["porttree"].dbapi

	adjust_configs(myopts, trees)
	apply_priorities(settings)

	if myaction == 'version':
		writemsg_stdout(getportageversion(
			settings["PORTDIR"], settings["ROOT"],
			settings.profile_path, settings["CHOST"],
			trees[settings["ROOT"]]["vartree"].dbapi) + '\n', noiselevel=-1)
		return 0
	elif myaction == 'help':
		_emerge.help.help(myopts, portage.output.havecolor)
		return 0

	spinner = stdout_spinner()
	if "candy" in settings.features:
		spinner.update = spinner.update_scroll

	if "--quiet" not in myopts:
		portage.deprecated_profile_check(settings=settings)
		repo_name_check(trees)
		repo_name_duplicate_check(trees)
		config_protect_check(trees)
	check_procfs()

	if "getbinpkg" in settings.features:
		myopts["--getbinpkg"] = True

	if "--getbinpkgonly" in myopts:
		myopts["--getbinpkg"] = True

	if "--getbinpkgonly" in myopts:
		myopts["--usepkgonly"] = True

	if "--getbinpkg" in myopts:
		myopts["--usepkg"] = True

	if "--usepkgonly" in myopts:
		myopts["--usepkg"] = True

	if "buildpkg" in settings.features or "--buildpkgonly" in myopts:
		myopts["--buildpkg"] = True

	if "--buildpkgonly" in myopts:
		# --buildpkgonly will not merge anything, so
		# it cancels all binary package options.
		for opt in ("--getbinpkg", "--getbinpkgonly",
			"--usepkg", "--usepkgonly"):
			myopts.pop(opt, None)
#.........这里部分代码省略.........