text: import functools
  import shlex
  import subprocess
  from contextlib import contextmanager
  from subprocess import PIPE, Popen
  from tempfile import TemporaryFile
  from types import MethodType
  from typing import ClassVar
  
  import plumbum.commands.modifiers
  from plumbum.commands.processes import iter_lines, run_proc
  
  __all__ = (
      "iter_lines",
      "run_proc",
      "shquote",
      "shquote_list",
      "RedirectionError",
      "BaseCommand",
      "Pipeline",
      "BaseRedirection",
      "BoundCommand",
      "BoundEnvCommand",
      "ConcreteCommand",
      "ERROUT",
      "StdinRedirection",
      "StdoutRedirection",
      "StderrRedirection",
      "AppendingStdoutRedirection",
      "StdinDataRedirection",
  )
  
  
  class RedirectionError(Exception):
      """Raised when an attempt is made to redirect an process' standard handle,
      which was already redirected to/from a file"""
  
  
  # ===================================================================================================
  # Utilities
  # ===================================================================================================
  # modified from the stdlib pipes module for windows
  _safechars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@%_-+=:,./"
  _funnychars = '"`$\\'
  
  
  def shquote(text):
      """Quotes the given text with shell escaping (assumes as syntax similar to ``sh``)"""
      text = str(text)
      return shlex.quote(text)
  
  
  def shquote_list(seq):
      return [shquote(item) for item in seq]
  
  
  # ===================================================================================================
  # Commands
  # ===================================================================================================
  class BaseCommand:
      """Base of all command objects"""
  
      __slots__ = ("cwd", "env", "custom_encoding", "__weakref__")
  
      def __str__(self):
          return " ".join(self.formulate())
  
      def __or__(self, other):
          """Creates a pipe with the other command"""
          return Pipeline(self, other)
  
      def __gt__(self, file):
          """Redirects the process' stdout to the given file"""
          return StdoutRedirection(self, file)
  
      def __rshift__(self, file):
          """Redirects the process' stdout to the given file (appending)"""
          return AppendingStdoutRedirection(self, file)
  
      def __ge__(self, file):
          """Redirects the process' stderr to the given file"""
          return StderrRedirection(self, file)
  
      def __lt__(self, file):
          """Redirects the given file into the process' stdin"""
          return StdinRedirection(self, file)
  
      def __lshift__(self, data):
          """Redirects the given data into the process' stdin"""
          return StdinDataRedirection(self, data)
  
      def __getitem__(self, args):
          """Creates a bound-command with the given arguments. Shortcut for
          bound_command."""
          if not isinstance(args, (tuple, list)):
              args = [
                  args,
              ]
          return self.bound_command(*args)
  
      def bound_command(self, *args):
          """Creates a bound-command with the given arguments"""
          if not args:
              return self
  
          if isinstance(self, BoundCommand):
              return BoundCommand(self.cmd, self.args + list(args))
  
          return BoundCommand(self, args)
  
      def __call__(self, *args, **kwargs):
          """A shortcut for `run(args)`, returning only the process' stdout"""
          return self.run(args, **kwargs)[1]
  
      def _get_encoding(self):
          raise NotImplementedError()
  
      def with_env(self, **env):
          """Returns a BoundEnvCommand with the given environment variables"""
          if not env:
              return self
          return BoundEnvCommand(self, env=env)
  
      def with_cwd(self, path):
          """
          Returns a BoundEnvCommand with the specified working directory.
          This overrides a cwd specified in a wrapping `machine.cwd()` context manager.
          """
          if not path:
              return self
          return BoundEnvCommand(self, cwd=path)
  
      setenv = with_env
  
      @property
      def machine(self):
          raise NotImplementedError()
  
      def formulate(self, level=0, args=()):
          """Formulates the command into a command-line, i.e., a list of shell-quoted strings
          that can be executed by ``Popen`` or shells.
  
          :param level: The nesting level of the formulation; it dictates how much shell-quoting
                        (if any) should be performed
  
          :param args: The arguments passed to this command (a tuple)
  
          :returns: A list of strings
          """
          raise NotImplementedError()
  
      def popen(self, args=(), **kwargs):
          """Spawns the given command, returning a ``Popen``-like object.
  
          .. note::
  
             When processes run in the **background** (either via ``popen`` or
             :class:`& BG <plumbum.commands.BG>`), their stdout/stderr pipes might fill up,
             causing them to hang. If you know a process produces output, be sure to consume it
             every once in a while, using a monitoring thread/reactor in the background.
             For more info, see `#48 <https://github.com/tomerfiliba/plumbum/issues/48>`_
  
          :param args: Any arguments to be passed to the process (a tuple)
  
          :param kwargs: Any keyword-arguments to be passed to the ``Popen`` constructor
  
          :returns: A ``Popen``-like object
          """
          raise NotImplementedError()
  
      def nohup(self, cwd=".", stdout="nohup.out", stderr=None, append=True):
          """Runs a command detached."""
          return self.machine.daemonic_popen(self, cwd, stdout, stderr, append)
  
      @contextmanager
      def bgrun(self, args=(), **kwargs):
          """Runs the given command as a context manager, allowing you to create a
          `pipeline <http://en.wikipedia.org/wiki/Pipeline_(computing)>`_ (not in the UNIX sense)
          of programs, parallelizing their work. In other words, instead of running programs
          one after the other, you can start all of them at the same time and wait for them to
          finish. For a more thorough review, see
          `Lightweight Asynchronism <http://tomerfiliba.com/blog/Toying-with-Context-Managers/>`_.
  
          Example::
  
              from plumbum.cmd import mkfs
  
              with mkfs["-t", "ext3", "/dev/sda1"] as p1:
                  with mkfs["-t", "ext3", "/dev/sdb1"] as p2:
                      pass
  
          .. note::
  
             When processes run in the **background** (either via ``popen`` or
             :class:`& BG <plumbum.commands.BG>`), their stdout/stderr pipes might fill up,
             causing them to hang. If you know a process produces output, be sure to consume it
             every once in a while, using a monitoring thread/reactor in the background.
             For more info, see `#48 <https://github.com/tomerfiliba/plumbum/issues/48>`_
  
          For the arguments, see :func:`run <BaseCommand.run>`.
  
          :returns: A Popen object, augmented with a ``.run()`` method, which returns a tuple of
                    (return code, stdout, stderr)
          """
          retcode = kwargs.pop("retcode", 0)
          timeout = kwargs.pop("timeout", None)
          p = self.popen(args, **kwargs)
          was_run = [False]
  
          def runner():
              if was_run[0]:
                  return None  # already done
              was_run[0] = True
              try:
                  return run_proc(p, retcode, timeout)
              finally:
                  del p.run  # to break cyclic reference p -> cell -> p
                  for f in [p.stdin, p.stdout, p.stderr]:
                      try:
                          f.close()
                      except Exception:
                          pass
  
          p.run = runner
          yield p
          runner()
  
      def run(self, args=(), **kwargs):
          """Runs the given command (equivalent to popen() followed by
          :func:`run_proc <plumbum.commands.run_proc>`). If the exit code of the process does
          not match the expected one, :class:`ProcessExecutionError
          <plumbum.commands.ProcessExecutionError>` is raised.
  
          :param args: Any arguments to be passed to the process (a tuple)
  
          :param retcode: The expected return code of this process (defaults to 0).
                          In order to disable exit-code validation, pass ``None``. It may also
                          be a tuple (or any iterable) of expected exit codes.
  
                          .. note:: this argument must be passed as a keyword argument.
  
          :param timeout: The maximal amount of time (in seconds) to allow the process to run.
                          ``None`` means no timeout is imposed; otherwise, if the process hasn't
                          terminated after that many seconds, the process will be forcefully
                          terminated an exception will be raised
  
                          .. note:: this argument must be passed as a keyword argument.
  
          :param kwargs: Any keyword-arguments to be passed to the ``Popen`` constructor
  
          :returns: A tuple of (return code, stdout, stderr)
          """
          with self.bgrun(args, **kwargs) as p:
              return p.run()
  
      def _use_modifier(self, modifier, args):
          """
          Applies a modifier to the current object (e.g. FG, NOHUP)
          :param modifier: The modifier class to apply (e.g. FG)
          :param args: A dictionary of arguments to pass to this modifier
          :return:
          """
          modifier_instance = modifier(**args)
          return self & modifier_instance
  
      def run_bg(self, **kwargs):
          """
          Run this command in the background. Uses all arguments from the BG construct
          :py:class: `plumbum.commands.modifiers.BG`
          """
          return self._use_modifier(plumbum.commands.modifiers.BG, kwargs)
  
      def run_fg(self, **kwargs):
          """
          Run this command in the foreground. Uses all arguments from the FG construct
          :py:class: `plumbum.commands.modifiers.FG`
          """
          return self._use_modifier(plumbum.commands.modifiers.FG, kwargs)
  
      def run_tee(self, **kwargs):
          """
          Run this command using the TEE construct. Inherits all arguments from TEE
          :py:class: `plumbum.commands.modifiers.TEE`
          """
          return self._use_modifier(plumbum.commands.modifiers.TEE, kwargs)
  
      def run_tf(self, **kwargs):
          """
          Run this command using the TF construct. Inherits all arguments from TF
          :py:class: `plumbum.commands.modifiers.TF`
          """
          return self._use_modifier(plumbum.commands.modifiers.TF, kwargs)
  
      def run_retcode(self, **kwargs):
          """
          Run this command using the RETCODE construct. Inherits all arguments from RETCODE
          :py:class: `plumbum.commands.modifiers.RETCODE`
          """
          return self._use_modifier(plumbum.commands.modifiers.RETCODE, kwargs)
  
      def run_nohup(self, **kwargs):
          """
          Run this command using the NOHUP construct. Inherits all arguments from NOHUP
          :py:class: `plumbum.commands.modifiers.NOHUP`
          """
          return self._use_modifier(plumbum.commands.modifiers.NOHUP, kwargs)
  
  
  class BoundCommand(BaseCommand):
      __slots__ = ("cmd", "args")
  
      def __init__(self, cmd, args):
          self.cmd = cmd
          self.args = list(args)
  
      def __repr__(self):
          return f"BoundCommand({self.cmd!r}, {self.args!r})"
  
      def _get_encoding(self):
          return self.cmd._get_encoding()
  
      def formulate(self, level=0, args=()):
          return self.cmd.formulate(level + 1, self.args + list(args))
  
      @property
      def machine(self):
          return self.cmd.machine
  
      def popen(self, args=(), **kwargs):
          if isinstance(args, str):
              args = [
                  args,
              ]
          return self.cmd.popen(self.args + list(args), **kwargs)
  
  
  class BoundEnvCommand(BaseCommand):
      __slots__ = ("cmd",)
  
      def __init__(self, cmd, env=None, cwd=None):
          self.cmd = cmd
          self.env = env or {}
          self.cwd = cwd
  
      def __repr__(self):
          return f"BoundEnvCommand({self.cmd!r}, {self.env!r})"
  
      def _get_encoding(self):
          return self.cmd._get_encoding()
  
      def formulate(self, level=0, args=()):
          return self.cmd.formulate(level, args)
  
      @property
      def machine(self):
          return self.cmd.machine
  
      def popen(self, args=(), cwd=None, env=None, **kwargs):
          env = env or {}
          return self.cmd.popen(
              args,
              cwd=self.cwd if cwd is None else cwd,
              env=dict(self.env, **env),
              **kwargs,
          )
  
  
  class Pipeline(BaseCommand):
      __slots__ = ("srccmd", "dstcmd")
  
      def __init__(self, srccmd, dstcmd):
          self.srccmd = srccmd
          self.dstcmd = dstcmd
  
      def __repr__(self):
          return f"Pipeline({self.srccmd!r}, {self.dstcmd!r})"
  
      def _get_encoding(self):
          return self.srccmd._get_encoding() or self.dstcmd._get_encoding()
  
      def formulate(self, level=0, args=()):
          return (
              self.srccmd.formulate(level + 1)
              + ["|"]
              + self.dstcmd.formulate(level + 1, args)
          )
  
      @property
      def machine(self):
          return self.srccmd.machine
  
      def popen(self, args=(), **kwargs):
          src_kwargs = kwargs.copy()
          src_kwargs["stdout"] = PIPE
          if "stdin" in kwargs:
              src_kwargs["stdin"] = kwargs["stdin"]
  
          srcproc = self.srccmd.popen(args, **src_kwargs)
          kwargs["stdin"] = srcproc.stdout
          dstproc = self.dstcmd.popen(**kwargs)
          # allow p1 to receive a SIGPIPE if p2 exits
          srcproc.stdout.close()
          if srcproc.stderr is not None:
              dstproc.stderr = srcproc.stderr
          if srcproc.stdin and src_kwargs.get("stdin") != PIPE:
              srcproc.stdin.close()
          dstproc.srcproc = srcproc
  
          # monkey-patch .wait() to wait on srcproc as well (it's expected to die when dstproc dies)
          dstproc_wait = dstproc.wait
  
          @functools.wraps(Popen.wait)
          def wait2(*args, **kwargs):
              rc_dst = dstproc_wait(*args, **kwargs)
              rc_src = srcproc.wait(*args, **kwargs)
              dstproc.returncode = rc_dst or rc_src
              return dstproc.returncode
  
          dstproc._proc.wait = wait2
  
          dstproc_verify = dstproc.verify
  
          def verify(proc, retcode, timeout, stdout, stderr):
              # TODO: right now it's impossible to specify different expected
              # return codes for different stages of the pipeline
              try:
                  or_retcode = [0] + list(retcode)
              except TypeError:
                  if retcode is None:
                      or_retcode = None  # no-retcode-verification acts "greedily"
                  else:
                      or_retcode = [0, retcode]
              proc.srcproc.verify(or_retcode, timeout, stdout, stderr)
              dstproc_verify(retcode, timeout, stdout, stderr)
  
          dstproc.verify = MethodType(verify, dstproc)
  
          dstproc.stdin = srcproc.stdin
          return dstproc
  
  
  class BaseRedirection(BaseCommand):
      __slots__ = ("cmd", "file")
      SYM: ClassVar[str]
      KWARG: ClassVar[str]
      MODE: ClassVar[str]
  
      def __init__(self, cmd, file):
          self.cmd = cmd
          self.file = file
  
      def _get_encoding(self):
          return self.cmd._get_encoding()
  
      def __repr__(self):
          return f"{self.__class__.__name__}({self.cmd!r}, {self.file!r})"
  
      def formulate(self, level=0, args=()):
          return self.cmd.formulate(level + 1, args) + [
              self.SYM,
              shquote(getattr(self.file, "name", self.file)),
          ]
  
      @property
      def machine(self):
          return self.cmd.machine
  
      def popen(self, args=(), **kwargs):
          from plumbum.machines.local import LocalPath
          from plumbum.machines.remote import RemotePath
  
          if self.KWARG in kwargs and kwargs[self.KWARG] not in (PIPE, None):
              raise RedirectionError(f"{self.KWARG} is already redirected")
          if isinstance(self.file, RemotePath):
              raise TypeError("Cannot redirect to/from remote paths")
          if isinstance(self.file, (str, LocalPath)):
              f = kwargs[self.KWARG] = open(str(self.file), self.MODE, encoding="utf-8")
          else:
              kwargs[self.KWARG] = self.file
              f = None
          try:
              return self.cmd.popen(args, **kwargs)
          finally:
              if f:
                  f.close()
  
  
  class StdinRedirection(BaseRedirection):
      __slots__ = ()
      SYM = "<"
      KWARG = "stdin"
      MODE = "r"
  
  
  class StdoutRedirection(BaseRedirection):
      __slots__ = ()
      SYM = ">"
      KWARG = "stdout"
      MODE = "w"
  
  
  class AppendingStdoutRedirection(BaseRedirection):
      __slots__ = ()
      SYM = ">>"
      KWARG = "stdout"
      MODE = "a"
  
  
  class StderrRedirection(BaseRedirection):
      __slots__ = ()
      SYM = "2>"
      KWARG = "stderr"
      MODE = "w"
  
  
  class _ERROUT(int):
      def __repr__(self):
          return "ERROUT"
  
      def __str__(self):
          return "&1"
  
  
  ERROUT = _ERROUT(subprocess.STDOUT)
  
  
  class StdinDataRedirection(BaseCommand):
      __slots__ = ("cmd", "data")
      CHUNK_SIZE = 16000
  
      def __init__(self, cmd, data):
          self.cmd = cmd
          self.data = data
  
      def _get_encoding(self):
          return self.cmd._get_encoding()
  
      def formulate(self, level=0, args=()):
          return [
              f"echo {shquote(self.data)}",
              "|",
              self.cmd.formulate(level + 1, args),
          ]
  
      @property
      def machine(self):
          return self.cmd.machine
  
      def popen(self, args=(), **kwargs):
          if "stdin" in kwargs and kwargs["stdin"] != PIPE:
              raise RedirectionError("stdin is already redirected")
          data = self.data
          if isinstance(data, str) and self._get_encoding() is not None:
              data = data.encode(self._get_encoding())
          f = TemporaryFile()
          while data:
              chunk = data[: self.CHUNK_SIZE]
              f.write(chunk)
              data = data[self.CHUNK_SIZE :]
          f.seek(0)
          # try:
          return self.cmd.popen(args, stdin=f, **kwargs)
          # finally:
          #    f.close()
  
  
  class ConcreteCommand(BaseCommand):
      QUOTE_LEVEL: ClassVar[int]
      __slots__ = ("executable", "custom_encoding")
  
      def __init__(self, executable, encoding):
          self.executable = executable
          self.custom_encoding = encoding
          self.cwd = None
          self.env = None
  
      def __str__(self):
          return str(self.executable)
  
      def __repr__(self):
          return f"{type(self).__name__}({self.executable})"
  
      def _get_encoding(self):
          return self.custom_encoding
  
      def formulate(self, level=0, args=()):
          argv = [str(self.executable)]
          for a in args:
              if a is None:
                  continue
              if isinstance(a, BaseCommand):
                  if level >= self.QUOTE_LEVEL:
                      argv.extend(shquote_list(a.formulate(level + 1)))
                  else:
                      argv.extend(a.formulate(level + 1))
              elif isinstance(a, (list, tuple)):
                  argv.extend(
                      shquote(b) if level >= self.QUOTE_LEVEL else str(b) for b in a
                  )
              else:
                  argv.append(shquote(a) if level >= self.QUOTE_LEVEL else str(a))
          # if self.custom_encoding:
          #    argv = [a.encode(self.custom_encoding) for a in argv if isinstance(a, str)]
          return argv
  
      @property
      def machine(self):
          raise NotImplementedError()
  
      def popen(self, args=(), **kwargs):
          raise NotImplementedError()
  