Source code for plumbum.machines.local

import contextlib
import logging
import os
import platform
import re
import subprocess
import sys
import time
from contextlib import contextmanager
from subprocess import PIPE, Popen
from tempfile import mkdtemp
from typing import Dict, Tuple

from plumbum.commands import CommandNotFound, ConcreteCommand
from plumbum.commands.daemons import posix_daemonize, win32_daemonize
from plumbum.commands.processes import iter_lines
from plumbum.lib import IS_WIN32, ProcInfo, StaticProperty
from plumbum.machines.base import BaseMachine, PopenAddons
from plumbum.machines.env import BaseEnv
from plumbum.machines.session import ShellSession
from plumbum.path.local import LocalPath, LocalWorkdir
from plumbum.path.remote import RemotePath

[docs]class PlumbumLocalPopen(PopenAddons): iter_lines = iter_lines
[docs] def __init__(self, *args, **kwargs): self._proc = Popen(*args, **kwargs) # pylint: disable=consider-using-with
def __iter__(self): return self.iter_lines() def __enter__(self): return self._proc.__enter__() def __exit__(self, *args, **kwargs): return self._proc.__exit__(*args, **kwargs) def __getattr__(self, name): return getattr(self._proc, name)
if IS_WIN32: from plumbum.machines._windows import IMAGE_SUBSYSTEM_WINDOWS_CUI, get_pe_subsystem logger = logging.getLogger("plumbum.local") # =================================================================================================== # Environment # ===================================================================================================
[docs]class LocalEnv(BaseEnv): """The local machine's environment; exposes a dict-like interface""" __slots__ = () CASE_SENSITIVE = not IS_WIN32
[docs] def __init__(self): # os.environ already takes care of upper'ing on windows super().__init__(LocalPath, os.path.pathsep, _curr=os.environ.copy()) if IS_WIN32 and "HOME" not in self and self.home is not None: self["HOME"] = self.home
[docs] def expand(self, expr): """Expands any environment variables and home shortcuts found in ``expr`` (like ``os.path.expanduser`` combined with ``os.path.expandvars``) :param expr: An expression containing environment variables (as ``$FOO``) or home shortcuts (as ``~/.bashrc``) :returns: The expanded string""" prev = os.environ os.environ = self.getdict() # noqa: B003 try: output = os.path.expanduser(os.path.expandvars(expr)) finally: os.environ = prev # noqa: B003 return output
[docs] def expanduser(self, expr): """Expand home shortcuts (e.g., ``~/foo/bar`` or ``~john/foo/bar``) :param expr: An expression containing home shortcuts :returns: The expanded string""" prev = os.environ os.environ = self.getdict() # noqa: B003 try: output = os.path.expanduser(expr) finally: os.environ = prev # noqa: B003 return output
# =================================================================================================== # Local Commands # ===================================================================================================
[docs]class LocalCommand(ConcreteCommand): __slots__ = () QUOTE_LEVEL = 2
[docs] def __init__(self, executable, encoding="auto"): ConcreteCommand.__init__( self, executable, local.custom_encoding if encoding == "auto" else encoding )
@property def machine(self): return local
[docs] def popen(self, args=(), cwd=None, env=None, **kwargs): if isinstance(args, str): args = (args,) return self.machine._popen( self.executable, self.formulate(0, args), cwd=self.cwd if cwd is None else cwd, env=self.env if env is None else env, **kwargs, )
# =================================================================================================== # Local Machine # ===================================================================================================
[docs]class LocalMachine(BaseMachine): """The *local machine* (a singleton object). It serves as an entry point to everything related to the local machine, such as working directory and environment manipulation, command creation, etc. Attributes: * ``cwd`` - the local working directory * ``env`` - the local environment * ``custom_encoding`` - the local machine's default encoding (``sys.getfilesystemencoding()``) """ cwd = StaticProperty(LocalWorkdir) env = LocalEnv() custom_encoding = sys.getfilesystemencoding() uname = platform.uname()[0] _program_cache: Dict[Tuple[str, str], LocalPath] = {}
[docs] def __init__(self): self._as_user_stack = []
if IS_WIN32: _EXTENSIONS = [ "", *env.get("PATHEXT", ":.exe:.bat").lower().split(os.path.pathsep), ] @classmethod def _which(cls, progname): progname = progname.lower() for p in cls.env.path: for ext in cls._EXTENSIONS: fn = p / (progname + ext) if fn.access("x") and not fn.is_dir(): return fn return None else: @classmethod def _which(cls, progname): for p in cls.env.path: fn = p / progname if fn.access("x") and not fn.is_dir(): return fn return None
[docs] @classmethod def which(cls, progname): """Looks up a program in the ``PATH``. If the program is not found, raises :class:`CommandNotFound <plumbum.commands.CommandNotFound>` :param progname: The program's name. Note that if underscores (``_``) are present in the name, and the exact name is not found, they will be replaced in turn by hyphens (``-``) then periods (``.``), and the name will be looked up again for each alternative :returns: A :class:`LocalPath <plumbum.machines.local.LocalPath>` """ key = (progname, cls.env.get("PATH", "")) with contextlib.suppress(KeyError): return cls._program_cache[key] alternatives = [progname] if "_" in progname: alternatives += [progname.replace("_", "-"), progname.replace("_", ".")] for pn in alternatives: path = cls._which(pn) if path: cls._program_cache[key] = path return path raise CommandNotFound(progname, list(cls.env.path))
[docs] def path(self, *parts): """A factory for :class:`LocalPaths <plumbum.path.local.LocalPath>`. Usage: ``p = local.path("/usr", "lib", "python2.7")`` """ parts2 = [str(self.cwd)] for p in parts: if isinstance(p, RemotePath): raise TypeError(f"Cannot construct LocalPath from {p!r}") parts2.append(self.env.expanduser(str(p))) return LocalPath(os.path.join(*parts2))
[docs] def __contains__(self, cmd): try: self[cmd] except CommandNotFound: return False return True
[docs] def __getitem__(self, cmd): """Returns a `Command` object representing the given program. ``cmd`` can be a string or a :class:`LocalPath <plumbum.path.local.LocalPath>`; if it is a path, a command representing this path will be returned; otherwise, the program name will be looked up in the system's ``PATH`` (using ``which``). Usage:: ls = local["ls"] """ if isinstance(cmd, LocalPath): return LocalCommand(cmd) if not isinstance(cmd, RemotePath): # handle "path-like" (pathlib.Path) objects cmd = os.fspath(cmd) if "/" in cmd or "\\" in cmd: # assume path return LocalCommand(local.path(cmd)) # search for command return LocalCommand(self.which(cmd)) raise TypeError(f"cmd must not be a RemotePath: {cmd!r}")
def _popen( self, executable, argv, stdin=PIPE, stdout=PIPE, stderr=PIPE, cwd=None, env=None, new_session=False, **kwargs, ): if new_session: kwargs["start_new_session"] = True if IS_WIN32 and "startupinfo" not in kwargs and stdin not in (sys.stdin, None): subsystem = get_pe_subsystem(str(executable)) if subsystem == IMAGE_SUBSYSTEM_WINDOWS_CUI: # don't open a new console sui = subprocess.STARTUPINFO() kwargs["startupinfo"] = sui if hasattr(subprocess, "_subprocess"): sui.dwFlags |= ( subprocess._subprocess.STARTF_USESHOWWINDOW ) # @UndefinedVariable sui.wShowWindow = ( subprocess._subprocess.SW_HIDE ) # @UndefinedVariable else: sui.dwFlags |= subprocess.STARTF_USESHOWWINDOW # @UndefinedVariable sui.wShowWindow = subprocess.SW_HIDE # @UndefinedVariable if cwd is None: cwd = self.cwd envs = [self.env, env] env = {} for _env in envs: if not _env: continue if isinstance(_env, BaseEnv): _env = _env.getdict() env.update(_env) if self._as_user_stack: argv, executable = self._as_user_stack[-1](argv) logger.debug("Running %r", argv) proc = PlumbumLocalPopen( argv, executable=str(executable), stdin=stdin, stdout=stdout, stderr=stderr, cwd=str(cwd), env=env, **kwargs, ) # bufsize = 4096 proc._start_time = time.time() proc.custom_encoding = self.custom_encoding proc.argv = argv return proc
[docs] def daemonic_popen(self, command, cwd="/", stdout=None, stderr=None, append=True): """ On POSIX systems: Run ``command`` as a UNIX daemon: fork a child process to setpid, redirect std handles to /dev/null, umask, close all fds, chdir to ``cwd``, then fork and exec ``command``. Returns a ``Popen`` process that can be used to poll/wait for the executed command (but keep in mind that you cannot access std handles) On Windows: Run ``command`` as a "Windows daemon": detach from controlling console and create a new process group. This means that the command will not receive console events and would survive its parent's termination. Returns a ``Popen`` object. .. note:: this does not run ``command`` as a system service, only detaches it from its parent. .. versionadded:: 1.3 """ if IS_WIN32: return win32_daemonize(command, cwd, stdout, stderr, append) return posix_daemonize(command, cwd, stdout, stderr, append)
if IS_WIN32: def list_processes(self): # pylint: disable=no-self-use """ Returns information about all running processes (on Windows: using ``tasklist``) .. versionadded:: 1.3 """ import csv tasklist = local["tasklist"] output = tasklist("/V", "/FO", "CSV") lines = output.splitlines() rows = csv.reader(lines) try: header = next(rows) except StopIteration: raise RuntimeError("tasklist must at least have header") from None imgidx = header.index("Image Name") pididx = header.index("PID") statidx = header.index("Status") useridx = header.index("User Name") for row in rows: yield ProcInfo( int(row[pididx]), row[useridx], row[statidx], row[imgidx] ) else:
[docs] def list_processes(self): """ Returns information about all running processes (on POSIX systems: using ``ps``) .. versionadded:: 1.3 """ ps = self["ps"] lines = ps("-e", "-o", "pid,uid,stat,args").splitlines() lines.pop(0) # header for line in lines: parts = line.strip().split() yield ProcInfo( int(parts[0]), int(parts[1]), parts[2], " ".join(parts[3:]) )
[docs] def pgrep(self, pattern): """ Process grep: return information about all processes whose command-line args match the given regex pattern """ pat = re.compile(pattern) for procinfo in self.list_processes(): if yield procinfo
[docs] def session(self, new_session=False): """Creates a new :class:`ShellSession <plumbum.session.ShellSession>` object; this invokes ``/bin/sh`` and executes commands on it over stdin/stdout/stderr""" return ShellSession(self["sh"].popen(new_session=new_session))
[docs] @contextmanager def tempdir(self): """A context manager that creates a temporary directory, which is removed when the context exits""" new_dir = self.path(mkdtemp()) try: yield new_dir finally: new_dir.delete()
[docs] @contextmanager def as_user(self, username=None): """Run nested commands as the given user. For example:: head = local["head"] head("-n1", "/dev/sda1") # this will fail... with local.as_user(): head("-n1", "/dev/sda1") :param username: The user to run commands as. If not given, root (or Administrator) is assumed """ if IS_WIN32: if username is None: username = "Administrator" self._as_user_stack.append( lambda argv: ( [ "runas", "/savecred", f"/user:{username}", '"' + " ".join(str(a) for a in argv) + '"', ], self.which("runas"), ) ) else: if username is None: self._as_user_stack.append( lambda argv: (["sudo", *list(argv)], self.which("sudo")) ) else: self._as_user_stack.append( lambda argv: ( ["sudo", "-u", username, *list(argv)], self.which("sudo"), ) ) try: yield finally: self._as_user_stack.pop(-1)
[docs] def as_root(self): """A shorthand for :func:`as_user("root") <plumbum.machines.local.LocalMachine.as_user>`""" return self.as_user()
python = LocalCommand(sys.executable, custom_encoding) """A command that represents the current python interpreter (``sys.executable``)"""
local = LocalMachine() """The *local machine* (a singleton object). It serves as an entry point to everything related to the local machine, such as working directory and environment manipulation, command creation, etc. Attributes: * ``cwd`` - the local working directory * ``env`` - the local environment * ``custom_encoding`` - the local machine's default encoding (``sys.getfilesystemencoding()``) """