| # subprocess - Subprocesses with accessible I/O streams |
| # |
| # For more information about this module, see PEP 324. |
| # |
| # Copyright (c) 2003-2005 by Peter Astrand <astrand@lysator.liu.se> |
| # |
| # Licensed to PSF under a Contributor Agreement. |
| # See http://www.python.org/2.4/license for licensing details. |
| |
| r"""Subprocesses with accessible I/O streams |
| |
| This module allows you to spawn processes, connect to their |
| input/output/error pipes, and obtain their return codes. |
| |
| For a complete description of this module see the Python documentation. |
| |
| Main API |
| ======== |
| run(...): Runs a command, waits for it to complete, then returns a |
| CompletedProcess instance. |
| Popen(...): A class for flexibly executing a command in a new process |
| |
| Constants |
| --------- |
| DEVNULL: Special value that indicates that os.devnull should be used |
| PIPE: Special value that indicates a pipe should be created |
| STDOUT: Special value that indicates that stderr should go to stdout |
| |
| |
| Older API |
| ========= |
| call(...): Runs a command, waits for it to complete, then returns |
| the return code. |
| check_call(...): Same as call() but raises CalledProcessError() |
| if return code is not 0 |
| check_output(...): Same as check_call() but returns the contents of |
| stdout instead of a return code |
| getoutput(...): Runs a command in the shell, waits for it to complete, |
| then returns the output |
| getstatusoutput(...): Runs a command in the shell, waits for it to complete, |
| then returns a (exitcode, output) tuple |
| """ |
| |
| import sys |
| _mswindows = (sys.platform == "win32") |
| |
| import io |
| import os |
| import time |
| import signal |
| import builtins |
| import warnings |
| import errno |
| from time import monotonic as _time |
| |
| # Exception classes used by this module. |
| class SubprocessError(Exception): pass |
| |
| |
| class CalledProcessError(SubprocessError): |
| """Raised when run() is called with check=True and the process |
| returns a non-zero exit status. |
| |
| Attributes: |
| cmd, returncode, stdout, stderr, output |
| """ |
| def __init__(self, returncode, cmd, output=None, stderr=None): |
| self.returncode = returncode |
| self.cmd = cmd |
| self.output = output |
| self.stderr = stderr |
| |
| def __str__(self): |
| if self.returncode and self.returncode < 0: |
| try: |
| return "Command '%s' died with %r." % ( |
| self.cmd, signal.Signals(-self.returncode)) |
| except ValueError: |
| return "Command '%s' died with unknown signal %d." % ( |
| self.cmd, -self.returncode) |
| else: |
| return "Command '%s' returned non-zero exit status %d." % ( |
| self.cmd, self.returncode) |
| |
| @property |
| def stdout(self): |
| """Alias for output attribute, to match stderr""" |
| return self.output |
| |
| @stdout.setter |
| def stdout(self, value): |
| # There's no obvious reason to set this, but allow it anyway so |
| # .stdout is a transparent alias for .output |
| self.output = value |
| |
| |
| class TimeoutExpired(SubprocessError): |
| """This exception is raised when the timeout expires while waiting for a |
| child process. |
| |
| Attributes: |
| cmd, output, stdout, stderr, timeout |
| """ |
| def __init__(self, cmd, timeout, output=None, stderr=None): |
| self.cmd = cmd |
| self.timeout = timeout |
| self.output = output |
| self.stderr = stderr |
| |
| def __str__(self): |
| return ("Command '%s' timed out after %s seconds" % |
| (self.cmd, self.timeout)) |
| |
| @property |
| def stdout(self): |
| return self.output |
| |
| @stdout.setter |
| def stdout(self, value): |
| # There's no obvious reason to set this, but allow it anyway so |
| # .stdout is a transparent alias for .output |
| self.output = value |
| |
| |
| if _mswindows: |
| import threading |
| import msvcrt |
| import _winapi |
| class STARTUPINFO: |
| def __init__(self, *, dwFlags=0, hStdInput=None, hStdOutput=None, |
| hStdError=None, wShowWindow=0, lpAttributeList=None): |
| self.dwFlags = dwFlags |
| self.hStdInput = hStdInput |
| self.hStdOutput = hStdOutput |
| self.hStdError = hStdError |
| self.wShowWindow = wShowWindow |
| self.lpAttributeList = lpAttributeList or {"handle_list": []} |
| |
| def _copy(self): |
| attr_list = self.lpAttributeList.copy() |
| if 'handle_list' in attr_list: |
| attr_list['handle_list'] = list(attr_list['handle_list']) |
| |
| return STARTUPINFO(dwFlags=self.dwFlags, |
| hStdInput=self.hStdInput, |
| hStdOutput=self.hStdOutput, |
| hStdError=self.hStdError, |
| wShowWindow=self.wShowWindow, |
| lpAttributeList=attr_list) |
| |
| else: |
| import _posixsubprocess |
| import select |
| import selectors |
| import threading |
| |
| # When select or poll has indicated that the file is writable, |
| # we can write up to _PIPE_BUF bytes without risk of blocking. |
| # POSIX defines PIPE_BUF as >= 512. |
| _PIPE_BUF = getattr(select, 'PIPE_BUF', 512) |
| |
| # poll/select have the advantage of not requiring any extra file |
| # descriptor, contrarily to epoll/kqueue (also, they require a single |
| # syscall). |
| if hasattr(selectors, 'PollSelector'): |
| _PopenSelector = selectors.PollSelector |
| else: |
| _PopenSelector = selectors.SelectSelector |
| |
| |
| __all__ = ["Popen", "PIPE", "STDOUT", "call", "check_call", "getstatusoutput", |
| "getoutput", "check_output", "run", "CalledProcessError", "DEVNULL", |
| "SubprocessError", "TimeoutExpired", "CompletedProcess"] |
| # NOTE: We intentionally exclude list2cmdline as it is |
| # considered an internal implementation detail. issue10838. |
| |
| if _mswindows: |
| from _winapi import (CREATE_NEW_CONSOLE, CREATE_NEW_PROCESS_GROUP, |
| STD_INPUT_HANDLE, STD_OUTPUT_HANDLE, |
| STD_ERROR_HANDLE, SW_HIDE, |
| STARTF_USESTDHANDLES, STARTF_USESHOWWINDOW, |
| ABOVE_NORMAL_PRIORITY_CLASS, BELOW_NORMAL_PRIORITY_CLASS, |
| HIGH_PRIORITY_CLASS, IDLE_PRIORITY_CLASS, |
| NORMAL_PRIORITY_CLASS, REALTIME_PRIORITY_CLASS, |
| CREATE_NO_WINDOW, DETACHED_PROCESS, |
| CREATE_DEFAULT_ERROR_MODE, CREATE_BREAKAWAY_FROM_JOB) |
| |
| __all__.extend(["CREATE_NEW_CONSOLE", "CREATE_NEW_PROCESS_GROUP", |
| "STD_INPUT_HANDLE", "STD_OUTPUT_HANDLE", |
| "STD_ERROR_HANDLE", "SW_HIDE", |
| "STARTF_USESTDHANDLES", "STARTF_USESHOWWINDOW", |
| "STARTUPINFO", |
| "ABOVE_NORMAL_PRIORITY_CLASS", "BELOW_NORMAL_PRIORITY_CLASS", |
| "HIGH_PRIORITY_CLASS", "IDLE_PRIORITY_CLASS", |
| "NORMAL_PRIORITY_CLASS", "REALTIME_PRIORITY_CLASS", |
| "CREATE_NO_WINDOW", "DETACHED_PROCESS", |
| "CREATE_DEFAULT_ERROR_MODE", "CREATE_BREAKAWAY_FROM_JOB"]) |
| |
| class Handle(int): |
| closed = False |
| |
| def Close(self, CloseHandle=_winapi.CloseHandle): |
| if not self.closed: |
| self.closed = True |
| CloseHandle(self) |
| |
| def Detach(self): |
| if not self.closed: |
| self.closed = True |
| return int(self) |
| raise ValueError("already closed") |
| |
| def __repr__(self): |
| return "%s(%d)" % (self.__class__.__name__, int(self)) |
| |
| __del__ = Close |
| __str__ = __repr__ |
| |
| |
| # This lists holds Popen instances for which the underlying process had not |
| # exited at the time its __del__ method got called: those processes are wait()ed |
| # for synchronously from _cleanup() when a new Popen object is created, to avoid |
| # zombie processes. |
| _active = [] |
| |
| def _cleanup(): |
| for inst in _active[:]: |
| res = inst._internal_poll(_deadstate=sys.maxsize) |
| if res is not None: |
| try: |
| _active.remove(inst) |
| except ValueError: |
| # This can happen if two threads create a new Popen instance. |
| # It's harmless that it was already removed, so ignore. |
| pass |
| |
| PIPE = -1 |
| STDOUT = -2 |
| DEVNULL = -3 |
| |
| |
| # XXX This function is only used by multiprocessing and the test suite, |
| # but it's here so that it can be imported when Python is compiled without |
| # threads. |
| |
| def _optim_args_from_interpreter_flags(): |
| """Return a list of command-line arguments reproducing the current |
| optimization settings in sys.flags.""" |
| args = [] |
| value = sys.flags.optimize |
| if value > 0: |
| args.append('-' + 'O' * value) |
| return args |
| |
| |
| def _args_from_interpreter_flags(): |
| """Return a list of command-line arguments reproducing the current |
| settings in sys.flags, sys.warnoptions and sys._xoptions.""" |
| flag_opt_map = { |
| 'debug': 'd', |
| # 'inspect': 'i', |
| # 'interactive': 'i', |
| 'dont_write_bytecode': 'B', |
| 'no_user_site': 's', |
| 'no_site': 'S', |
| 'ignore_environment': 'E', |
| 'verbose': 'v', |
| 'bytes_warning': 'b', |
| 'quiet': 'q', |
| # -O is handled in _optim_args_from_interpreter_flags() |
| } |
| args = _optim_args_from_interpreter_flags() |
| for flag, opt in flag_opt_map.items(): |
| v = getattr(sys.flags, flag) |
| if v > 0: |
| args.append('-' + opt * v) |
| |
| # -W options |
| warnopts = sys.warnoptions[:] |
| bytes_warning = sys.flags.bytes_warning |
| xoptions = getattr(sys, '_xoptions', {}) |
| dev_mode = ('dev' in xoptions) |
| |
| if bytes_warning > 1: |
| warnopts.remove("error::BytesWarning") |
| elif bytes_warning: |
| warnopts.remove("default::BytesWarning") |
| if dev_mode: |
| warnopts.remove('default') |
| for opt in warnopts: |
| args.append('-W' + opt) |
| |
| # -X options |
| if dev_mode: |
| args.extend(('-X', 'dev')) |
| for opt in ('faulthandler', 'tracemalloc', 'importtime', |
| 'showalloccount', 'showrefcount', 'utf8'): |
| if opt in xoptions: |
| value = xoptions[opt] |
| if value is True: |
| arg = opt |
| else: |
| arg = '%s=%s' % (opt, value) |
| args.extend(('-X', arg)) |
| |
| return args |
| |
| |
| def call(*popenargs, timeout=None, **kwargs): |
| """Run command with arguments. Wait for command to complete or |
| timeout, then return the returncode attribute. |
| |
| The arguments are the same as for the Popen constructor. Example: |
| |
| retcode = call(["ls", "-l"]) |
| """ |
| with Popen(*popenargs, **kwargs) as p: |
| try: |
| return p.wait(timeout=timeout) |
| except: # Including KeyboardInterrupt, wait handled that. |
| p.kill() |
| # We don't call p.wait() again as p.__exit__ does that for us. |
| raise |
| |
| |
| def check_call(*popenargs, **kwargs): |
| """Run command with arguments. Wait for command to complete. If |
| the exit code was zero then return, otherwise raise |
| CalledProcessError. The CalledProcessError object will have the |
| return code in the returncode attribute. |
| |
| The arguments are the same as for the call function. Example: |
| |
| check_call(["ls", "-l"]) |
| """ |
| retcode = call(*popenargs, **kwargs) |
| if retcode: |
| cmd = kwargs.get("args") |
| if cmd is None: |
| cmd = popenargs[0] |
| raise CalledProcessError(retcode, cmd) |
| return 0 |
| |
| |
| def check_output(*popenargs, timeout=None, **kwargs): |
| r"""Run command with arguments and return its output. |
| |
| If the exit code was non-zero it raises a CalledProcessError. The |
| CalledProcessError object will have the return code in the returncode |
| attribute and output in the output attribute. |
| |
| The arguments are the same as for the Popen constructor. Example: |
| |
| >>> check_output(["ls", "-l", "/dev/null"]) |
| b'crw-rw-rw- 1 root root 1, 3 Oct 18 2007 /dev/null\n' |
| |
| The stdout argument is not allowed as it is used internally. |
| To capture standard error in the result, use stderr=STDOUT. |
| |
| >>> check_output(["/bin/sh", "-c", |
| ... "ls -l non_existent_file ; exit 0"], |
| ... stderr=STDOUT) |
| b'ls: non_existent_file: No such file or directory\n' |
| |
| There is an additional optional argument, "input", allowing you to |
| pass a string to the subprocess's stdin. If you use this argument |
| you may not also use the Popen constructor's "stdin" argument, as |
| it too will be used internally. Example: |
| |
| >>> check_output(["sed", "-e", "s/foo/bar/"], |
| ... input=b"when in the course of fooman events\n") |
| b'when in the course of barman events\n' |
| |
| By default, all communication is in bytes, and therefore any "input" |
| should be bytes, and the return value wil be bytes. If in text mode, |
| any "input" should be a string, and the return value will be a string |
| decoded according to locale encoding, or by "encoding" if set. Text mode |
| is triggered by setting any of text, encoding, errors or universal_newlines. |
| """ |
| if 'stdout' in kwargs: |
| raise ValueError('stdout argument not allowed, it will be overridden.') |
| |
| if 'input' in kwargs and kwargs['input'] is None: |
| # Explicitly passing input=None was previously equivalent to passing an |
| # empty string. That is maintained here for backwards compatibility. |
| kwargs['input'] = '' if kwargs.get('universal_newlines', False) else b'' |
| |
| return run(*popenargs, stdout=PIPE, timeout=timeout, check=True, |
| **kwargs).stdout |
| |
| |
| class CompletedProcess(object): |
| """A process that has finished running. |
| |
| This is returned by run(). |
| |
| Attributes: |
| args: The list or str args passed to run(). |
| returncode: The exit code of the process, negative for signals. |
| stdout: The standard output (None if not captured). |
| stderr: The standard error (None if not captured). |
| """ |
| def __init__(self, args, returncode, stdout=None, stderr=None): |
| self.args = args |
| self.returncode = returncode |
| self.stdout = stdout |
| self.stderr = stderr |
| |
| def __repr__(self): |
| args = ['args={!r}'.format(self.args), |
| 'returncode={!r}'.format(self.returncode)] |
| if self.stdout is not None: |
| args.append('stdout={!r}'.format(self.stdout)) |
| if self.stderr is not None: |
| args.append('stderr={!r}'.format(self.stderr)) |
| return "{}({})".format(type(self).__name__, ', '.join(args)) |
| |
| def check_returncode(self): |
| """Raise CalledProcessError if the exit code is non-zero.""" |
| if self.returncode: |
| raise CalledProcessError(self.returncode, self.args, self.stdout, |
| self.stderr) |
| |
| |
| def run(*popenargs, |
| input=None, capture_output=False, timeout=None, check=False, **kwargs): |
| """Run command with arguments and return a CompletedProcess instance. |
| |
| The returned instance will have attributes args, returncode, stdout and |
| stderr. By default, stdout and stderr are not captured, and those attributes |
| will be None. Pass stdout=PIPE and/or stderr=PIPE in order to capture them. |
| |
| If check is True and the exit code was non-zero, it raises a |
| CalledProcessError. The CalledProcessError object will have the return code |
| in the returncode attribute, and output & stderr attributes if those streams |
| were captured. |
| |
| If timeout is given, and the process takes too long, a TimeoutExpired |
| exception will be raised. |
| |
| There is an optional argument "input", allowing you to |
| pass bytes or a string to the subprocess's stdin. If you use this argument |
| you may not also use the Popen constructor's "stdin" argument, as |
| it will be used internally. |
| |
| By default, all communication is in bytes, and therefore any "input" should |
| be bytes, and the stdout and stderr will be bytes. If in text mode, any |
| "input" should be a string, and stdout and stderr will be strings decoded |
| according to locale encoding, or by "encoding" if set. Text mode is |
| triggered by setting any of text, encoding, errors or universal_newlines. |
| |
| The other arguments are the same as for the Popen constructor. |
| """ |
| if input is not None: |
| if 'stdin' in kwargs: |
| raise ValueError('stdin and input arguments may not both be used.') |
| kwargs['stdin'] = PIPE |
| |
| if capture_output: |
| if ('stdout' in kwargs) or ('stderr' in kwargs): |
| raise ValueError('stdout and stderr arguments may not be used ' |
| 'with capture_output.') |
| kwargs['stdout'] = PIPE |
| kwargs['stderr'] = PIPE |
| |
| with Popen(*popenargs, **kwargs) as process: |
| try: |
| stdout, stderr = process.communicate(input, timeout=timeout) |
| except TimeoutExpired: |
| process.kill() |
| stdout, stderr = process.communicate() |
| raise TimeoutExpired(process.args, timeout, output=stdout, |
| stderr=stderr) |
| except: # Including KeyboardInterrupt, communicate handled that. |
| process.kill() |
| # We don't call process.wait() as .__exit__ does that for us. |
| raise |
| retcode = process.poll() |
| if check and retcode: |
| raise CalledProcessError(retcode, process.args, |
| output=stdout, stderr=stderr) |
| return CompletedProcess(process.args, retcode, stdout, stderr) |
| |
| |
| def list2cmdline(seq): |
| """ |
| Translate a sequence of arguments into a command line |
| string, using the same rules as the MS C runtime: |
| |
| 1) Arguments are delimited by white space, which is either a |
| space or a tab. |
| |
| 2) A string surrounded by double quotation marks is |
| interpreted as a single argument, regardless of white space |
| contained within. A quoted string can be embedded in an |
| argument. |
| |
| 3) A double quotation mark preceded by a backslash is |
| interpreted as a literal double quotation mark. |
| |
| 4) Backslashes are interpreted literally, unless they |
| immediately precede a double quotation mark. |
| |
| 5) If backslashes immediately precede a double quotation mark, |
| every pair of backslashes is interpreted as a literal |
| backslash. If the number of backslashes is odd, the last |
| backslash escapes the next double quotation mark as |
| described in rule 3. |
| """ |
| |
| # See |
| # http://msdn.microsoft.com/en-us/library/17w5ykft.aspx |
| # or search http://msdn.microsoft.com for |
| # "Parsing C++ Command-Line Arguments" |
| result = [] |
| needquote = False |
| for arg in seq: |
| bs_buf = [] |
| |
| # Add a space to separate this argument from the others |
| if result: |
| result.append(' ') |
| |
| needquote = (" " in arg) or ("\t" in arg) or not arg |
| if needquote: |
| result.append('"') |
| |
| for c in arg: |
| if c == '\\': |
| # Don't know if we need to double yet. |
| bs_buf.append(c) |
| elif c == '"': |
| # Double backslashes. |
| result.append('\\' * len(bs_buf)*2) |
| bs_buf = [] |
| result.append('\\"') |
| else: |
| # Normal char |
| if bs_buf: |
| result.extend(bs_buf) |
| bs_buf = [] |
| result.append(c) |
| |
| # Add remaining backslashes, if any. |
| if bs_buf: |
| result.extend(bs_buf) |
| |
| if needquote: |
| result.extend(bs_buf) |
| result.append('"') |
| |
| return ''.join(result) |
| |
| |
| # Various tools for executing commands and looking at their output and status. |
| # |
| |
| def getstatusoutput(cmd): |
| """Return (exitcode, output) of executing cmd in a shell. |
| |
| Execute the string 'cmd' in a shell with 'check_output' and |
| return a 2-tuple (status, output). The locale encoding is used |
| to decode the output and process newlines. |
| |
| A trailing newline is stripped from the output. |
| The exit status for the command can be interpreted |
| according to the rules for the function 'wait'. Example: |
| |
| >>> import subprocess |
| >>> subprocess.getstatusoutput('ls /bin/ls') |
| (0, '/bin/ls') |
| >>> subprocess.getstatusoutput('cat /bin/junk') |
| (1, 'cat: /bin/junk: No such file or directory') |
| >>> subprocess.getstatusoutput('/bin/junk') |
| (127, 'sh: /bin/junk: not found') |
| >>> subprocess.getstatusoutput('/bin/kill $$') |
| (-15, '') |
| """ |
| try: |
| data = check_output(cmd, shell=True, text=True, stderr=STDOUT) |
| exitcode = 0 |
| except CalledProcessError as ex: |
| data = ex.output |
| exitcode = ex.returncode |
| if data[-1:] == '\n': |
| data = data[:-1] |
| return exitcode, data |
| |
| def getoutput(cmd): |
| """Return output (stdout or stderr) of executing cmd in a shell. |
| |
| Like getstatusoutput(), except the exit status is ignored and the return |
| value is a string containing the command's output. Example: |
| |
| >>> import subprocess |
| >>> subprocess.getoutput('ls /bin/ls') |
| '/bin/ls' |
| """ |
| return getstatusoutput(cmd)[1] |
| |
| |
| class Popen(object): |
| """ Execute a child program in a new process. |
| |
| For a complete description of the arguments see the Python documentation. |
| |
| Arguments: |
| args: A string, or a sequence of program arguments. |
| |
| bufsize: supplied as the buffering argument to the open() function when |
| creating the stdin/stdout/stderr pipe file objects |
| |
| executable: A replacement program to execute. |
| |
| stdin, stdout and stderr: These specify the executed programs' standard |
| input, standard output and standard error file handles, respectively. |
| |
| preexec_fn: (POSIX only) An object to be called in the child process |
| just before the child is executed. |
| |
| close_fds: Controls closing or inheriting of file descriptors. |
| |
| shell: If true, the command will be executed through the shell. |
| |
| cwd: Sets the current directory before the child is executed. |
| |
| env: Defines the environment variables for the new process. |
| |
| text: If true, decode stdin, stdout and stderr using the given encoding |
| (if set) or the system default otherwise. |
| |
| universal_newlines: Alias of text, provided for backwards compatibility. |
| |
| startupinfo and creationflags (Windows only) |
| |
| restore_signals (POSIX only) |
| |
| start_new_session (POSIX only) |
| |
| pass_fds (POSIX only) |
| |
| encoding and errors: Text mode encoding and error handling to use for |
| file objects stdin, stdout and stderr. |
| |
| Attributes: |
| stdin, stdout, stderr, pid, returncode |
| """ |
| _child_created = False # Set here since __del__ checks it |
| |
| def __init__(self, args, bufsize=-1, executable=None, |
| stdin=None, stdout=None, stderr=None, |
| preexec_fn=None, close_fds=True, |
| shell=False, cwd=None, env=None, universal_newlines=None, |
| startupinfo=None, creationflags=0, |
| restore_signals=True, start_new_session=False, |
| pass_fds=(), *, encoding=None, errors=None, text=None): |
| """Create new Popen instance.""" |
| _cleanup() |
| # Held while anything is calling waitpid before returncode has been |
| # updated to prevent clobbering returncode if wait() or poll() are |
| # called from multiple threads at once. After acquiring the lock, |
| # code must re-check self.returncode to see if another thread just |
| # finished a waitpid() call. |
| self._waitpid_lock = threading.Lock() |
| |
| self._input = None |
| self._communication_started = False |
| if bufsize is None: |
| bufsize = -1 # Restore default |
| if not isinstance(bufsize, int): |
| raise TypeError("bufsize must be an integer") |
| |
| if _mswindows: |
| if preexec_fn is not None: |
| raise ValueError("preexec_fn is not supported on Windows " |
| "platforms") |
| else: |
| # POSIX |
| if pass_fds and not close_fds: |
| warnings.warn("pass_fds overriding close_fds.", RuntimeWarning) |
| close_fds = True |
| if startupinfo is not None: |
| raise ValueError("startupinfo is only supported on Windows " |
| "platforms") |
| if creationflags != 0: |
| raise ValueError("creationflags is only supported on Windows " |
| "platforms") |
| |
| self.args = args |
| self.stdin = None |
| self.stdout = None |
| self.stderr = None |
| self.pid = None |
| self.returncode = None |
| self.encoding = encoding |
| self.errors = errors |
| |
| # Validate the combinations of text and universal_newlines |
| if (text is not None and universal_newlines is not None |
| and bool(universal_newlines) != bool(text)): |
| raise SubprocessError('Cannot disambiguate when both text ' |
| 'and universal_newlines are supplied but ' |
| 'different. Pass one or the other.') |
| |
| # Input and output objects. The general principle is like |
| # this: |
| # |
| # Parent Child |
| # ------ ----- |
| # p2cwrite ---stdin---> p2cread |
| # c2pread <--stdout--- c2pwrite |
| # errread <--stderr--- errwrite |
| # |
| # On POSIX, the child objects are file descriptors. On |
| # Windows, these are Windows file handles. The parent objects |
| # are file descriptors on both platforms. The parent objects |
| # are -1 when not using PIPEs. The child objects are -1 |
| # when not redirecting. |
| |
| (p2cread, p2cwrite, |
| c2pread, c2pwrite, |
| errread, errwrite) = self._get_handles(stdin, stdout, stderr) |
| |
| # We wrap OS handles *before* launching the child, otherwise a |
| # quickly terminating child could make our fds unwrappable |
| # (see #8458). |
| |
| if _mswindows: |
| if p2cwrite != -1: |
| p2cwrite = msvcrt.open_osfhandle(p2cwrite.Detach(), 0) |
| if c2pread != -1: |
| c2pread = msvcrt.open_osfhandle(c2pread.Detach(), 0) |
| if errread != -1: |
| errread = msvcrt.open_osfhandle(errread.Detach(), 0) |
| |
| self.text_mode = encoding or errors or text or universal_newlines |
| |
| # How long to resume waiting on a child after the first ^C. |
| # There is no right value for this. The purpose is to be polite |
| # yet remain good for interactive users trying to exit a tool. |
| self._sigint_wait_secs = 0.25 # 1/xkcd221.getRandomNumber() |
| |
| self._closed_child_pipe_fds = False |
| |
| try: |
| if p2cwrite != -1: |
| self.stdin = io.open(p2cwrite, 'wb', bufsize) |
| if self.text_mode: |
| self.stdin = io.TextIOWrapper(self.stdin, write_through=True, |
| line_buffering=(bufsize == 1), |
| encoding=encoding, errors=errors) |
| if c2pread != -1: |
| self.stdout = io.open(c2pread, 'rb', bufsize) |
| if self.text_mode: |
| self.stdout = io.TextIOWrapper(self.stdout, |
| encoding=encoding, errors=errors) |
| if errread != -1: |
| self.stderr = io.open(errread, 'rb', bufsize) |
| if self.text_mode: |
| self.stderr = io.TextIOWrapper(self.stderr, |
| encoding=encoding, errors=errors) |
| |
| self._execute_child(args, executable, preexec_fn, close_fds, |
| pass_fds, cwd, env, |
| startupinfo, creationflags, shell, |
| p2cread, p2cwrite, |
| c2pread, c2pwrite, |
| errread, errwrite, |
| restore_signals, start_new_session) |
| except: |
| # Cleanup if the child failed starting. |
| for f in filter(None, (self.stdin, self.stdout, self.stderr)): |
| try: |
| f.close() |
| except OSError: |
| pass # Ignore EBADF or other errors. |
| |
| if not self._closed_child_pipe_fds: |
| to_close = [] |
| if stdin == PIPE: |
| to_close.append(p2cread) |
| if stdout == PIPE: |
| to_close.append(c2pwrite) |
| if stderr == PIPE: |
| to_close.append(errwrite) |
| if hasattr(self, '_devnull'): |
| to_close.append(self._devnull) |
| for fd in to_close: |
| try: |
| if _mswindows and isinstance(fd, Handle): |
| fd.Close() |
| else: |
| os.close(fd) |
| except OSError: |
| pass |
| |
| raise |
| |
| @property |
| def universal_newlines(self): |
| # universal_newlines as retained as an alias of text_mode for API |
| # compatibility. bpo-31756 |
| return self.text_mode |
| |
| @universal_newlines.setter |
| def universal_newlines(self, universal_newlines): |
| self.text_mode = bool(universal_newlines) |
| |
| def _translate_newlines(self, data, encoding, errors): |
| data = data.decode(encoding, errors) |
| return data.replace("\r\n", "\n").replace("\r", "\n") |
| |
| def __enter__(self): |
| return self |
| |
| def __exit__(self, exc_type, value, traceback): |
| if self.stdout: |
| self.stdout.close() |
| if self.stderr: |
| self.stderr.close() |
| try: # Flushing a BufferedWriter may raise an error |
| if self.stdin: |
| self.stdin.close() |
| finally: |
| if exc_type == KeyboardInterrupt: |
| # https://bugs.python.org/issue25942 |
| # In the case of a KeyboardInterrupt we assume the SIGINT |
| # was also already sent to our child processes. We can't |
| # block indefinitely as that is not user friendly. |
| # If we have not already waited a brief amount of time in |
| # an interrupted .wait() or .communicate() call, do so here |
| # for consistency. |
| if self._sigint_wait_secs > 0: |
| try: |
| self._wait(timeout=self._sigint_wait_secs) |
| except TimeoutExpired: |
| pass |
| self._sigint_wait_secs = 0 # Note that this has been done. |
| return # resume the KeyboardInterrupt |
| |
| # Wait for the process to terminate, to avoid zombies. |
| self.wait() |
| |
| def __del__(self, _maxsize=sys.maxsize, _warn=warnings.warn): |
| if not self._child_created: |
| # We didn't get to successfully create a child process. |
| return |
| if self.returncode is None: |
| # Not reading subprocess exit status creates a zombie process which |
| # is only destroyed at the parent python process exit |
| _warn("subprocess %s is still running" % self.pid, |
| ResourceWarning, source=self) |
| # In case the child hasn't been waited on, check if it's done. |
| self._internal_poll(_deadstate=_maxsize) |
| if self.returncode is None and _active is not None: |
| # Child is still running, keep us alive until we can wait on it. |
| _active.append(self) |
| |
| def _get_devnull(self): |
| if not hasattr(self, '_devnull'): |
| self._devnull = os.open(os.devnull, os.O_RDWR) |
| return self._devnull |
| |
| def _stdin_write(self, input): |
| if input: |
| try: |
| self.stdin.write(input) |
| except BrokenPipeError: |
| pass # communicate() must ignore broken pipe errors. |
| except OSError as exc: |
| if exc.errno == errno.EINVAL: |
| # bpo-19612, bpo-30418: On Windows, stdin.write() fails |
| # with EINVAL if the child process exited or if the child |
| # process is still running but closed the pipe. |
| pass |
| else: |
| raise |
| |
| try: |
| self.stdin.close() |
| except BrokenPipeError: |
| pass # communicate() must ignore broken pipe errors. |
| except OSError as exc: |
| if exc.errno == errno.EINVAL: |
| pass |
| else: |
| raise |
| |
| def communicate(self, input=None, timeout=None): |
| """Interact with process: Send data to stdin and close it. |
| Read data from stdout and stderr, until end-of-file is |
| reached. Wait for process to terminate. |
| |
| The optional "input" argument should be data to be sent to the |
| child process, or None, if no data should be sent to the child. |
| communicate() returns a tuple (stdout, stderr). |
| |
| By default, all communication is in bytes, and therefore any |
| "input" should be bytes, and the (stdout, stderr) will be bytes. |
| If in text mode (indicated by self.text_mode), any "input" should |
| be a string, and (stdout, stderr) will be strings decoded |
| according to locale encoding, or by "encoding" if set. Text mode |
| is triggered by setting any of text, encoding, errors or |
| universal_newlines. |
| """ |
| |
| if self._communication_started and input: |
| raise ValueError("Cannot send input after starting communication") |
| |
| # Optimization: If we are not worried about timeouts, we haven't |
| # started communicating, and we have one or zero pipes, using select() |
| # or threads is unnecessary. |
| if (timeout is None and not self._communication_started and |
| [self.stdin, self.stdout, self.stderr].count(None) >= 2): |
| stdout = None |
| stderr = None |
| if self.stdin: |
| self._stdin_write(input) |
| elif self.stdout: |
| stdout = self.stdout.read() |
| self.stdout.close() |
| elif self.stderr: |
| stderr = self.stderr.read() |
| self.stderr.close() |
| self.wait() |
| else: |
| if timeout is not None: |
| endtime = _time() + timeout |
| else: |
| endtime = None |
| |
| try: |
| stdout, stderr = self._communicate(input, endtime, timeout) |
| except KeyboardInterrupt: |
| # https://bugs.python.org/issue25942 |
| # See the detailed comment in .wait(). |
| if timeout is not None: |
| sigint_timeout = min(self._sigint_wait_secs, |
| self._remaining_time(endtime)) |
| else: |
| sigint_timeout = self._sigint_wait_secs |
| self._sigint_wait_secs = 0 # nothing else should wait. |
| try: |
| self._wait(timeout=sigint_timeout) |
| except TimeoutExpired: |
| pass |
| raise # resume the KeyboardInterrupt |
| |
| finally: |
| self._communication_started = True |
| |
| sts = self.wait(timeout=self._remaining_time(endtime)) |
| |
| return (stdout, stderr) |
| |
| |
| def poll(self): |
| """Check if child process has terminated. Set and return returncode |
| attribute.""" |
| return self._internal_poll() |
| |
| |
| def _remaining_time(self, endtime): |
| """Convenience for _communicate when computing timeouts.""" |
| if endtime is None: |
| return None |
| else: |
| return endtime - _time() |
| |
| |
| def _check_timeout(self, endtime, orig_timeout): |
| """Convenience for checking if a timeout has expired.""" |
| if endtime is None: |
| return |
| if _time() > endtime: |
| raise TimeoutExpired(self.args, orig_timeout) |
| |
| |
| def wait(self, timeout=None): |
| """Wait for child process to terminate; returns self.returncode.""" |
| if timeout is not None: |
| endtime = _time() + timeout |
| try: |
| return self._wait(timeout=timeout) |
| except KeyboardInterrupt: |
| # https://bugs.python.org/issue25942 |
| # The first keyboard interrupt waits briefly for the child to |
| # exit under the common assumption that it also received the ^C |
| # generated SIGINT and will exit rapidly. |
| if timeout is not None: |
| sigint_timeout = min(self._sigint_wait_secs, |
| self._remaining_time(endtime)) |
| else: |
| sigint_timeout = self._sigint_wait_secs |
| self._sigint_wait_secs = 0 # nothing else should wait. |
| try: |
| self._wait(timeout=sigint_timeout) |
| except TimeoutExpired: |
| pass |
| raise # resume the KeyboardInterrupt |
| |
| |
| if _mswindows: |
| # |
| # Windows methods |
| # |
| def _get_handles(self, stdin, stdout, stderr): |
| """Construct and return tuple with IO objects: |
| p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite |
| """ |
| if stdin is None and stdout is None and stderr is None: |
| return (-1, -1, -1, -1, -1, -1) |
| |
| p2cread, p2cwrite = -1, -1 |
| c2pread, c2pwrite = -1, -1 |
| errread, errwrite = -1, -1 |
| |
| if stdin is None: |
| p2cread = _winapi.GetStdHandle(_winapi.STD_INPUT_HANDLE) |
| if p2cread is None: |
| p2cread, _ = _winapi.CreatePipe(None, 0) |
| p2cread = Handle(p2cread) |
| _winapi.CloseHandle(_) |
| elif stdin == PIPE: |
| p2cread, p2cwrite = _winapi.CreatePipe(None, 0) |
| p2cread, p2cwrite = Handle(p2cread), Handle(p2cwrite) |
| elif stdin == DEVNULL: |
| p2cread = msvcrt.get_osfhandle(self._get_devnull()) |
| elif isinstance(stdin, int): |
| p2cread = msvcrt.get_osfhandle(stdin) |
| else: |
| # Assuming file-like object |
| p2cread = msvcrt.get_osfhandle(stdin.fileno()) |
| p2cread = self._make_inheritable(p2cread) |
| |
| if stdout is None: |
| c2pwrite = _winapi.GetStdHandle(_winapi.STD_OUTPUT_HANDLE) |
| if c2pwrite is None: |
| _, c2pwrite = _winapi.CreatePipe(None, 0) |
| c2pwrite = Handle(c2pwrite) |
| _winapi.CloseHandle(_) |
| elif stdout == PIPE: |
| c2pread, c2pwrite = _winapi.CreatePipe(None, 0) |
| c2pread, c2pwrite = Handle(c2pread), Handle(c2pwrite) |
| elif stdout == DEVNULL: |
| c2pwrite = msvcrt.get_osfhandle(self._get_devnull()) |
| elif isinstance(stdout, int): |
| c2pwrite = msvcrt.get_osfhandle(stdout) |
| else: |
| # Assuming file-like object |
| c2pwrite = msvcrt.get_osfhandle(stdout.fileno()) |
| c2pwrite = self._make_inheritable(c2pwrite) |
| |
| if stderr is None: |
| errwrite = _winapi.GetStdHandle(_winapi.STD_ERROR_HANDLE) |
| if errwrite is None: |
| _, errwrite = _winapi.CreatePipe(None, 0) |
| errwrite = Handle(errwrite) |
| _winapi.CloseHandle(_) |
| elif stderr == PIPE: |
| errread, errwrite = _winapi.CreatePipe(None, 0) |
| errread, errwrite = Handle(errread), Handle(errwrite) |
| elif stderr == STDOUT: |
| errwrite = c2pwrite |
| elif stderr == DEVNULL: |
| errwrite = msvcrt.get_osfhandle(self._get_devnull()) |
| elif isinstance(stderr, int): |
| errwrite = msvcrt.get_osfhandle(stderr) |
| else: |
| # Assuming file-like object |
| errwrite = msvcrt.get_osfhandle(stderr.fileno()) |
| errwrite = self._make_inheritable(errwrite) |
| |
| return (p2cread, p2cwrite, |
| c2pread, c2pwrite, |
| errread, errwrite) |
| |
| |
| def _make_inheritable(self, handle): |
| """Return a duplicate of handle, which is inheritable""" |
| h = _winapi.DuplicateHandle( |
| _winapi.GetCurrentProcess(), handle, |
| _winapi.GetCurrentProcess(), 0, 1, |
| _winapi.DUPLICATE_SAME_ACCESS) |
| return Handle(h) |
| |
| |
| def _filter_handle_list(self, handle_list): |
| """Filter out console handles that can't be used |
| in lpAttributeList["handle_list"] and make sure the list |
| isn't empty. This also removes duplicate handles.""" |
| # An handle with it's lowest two bits set might be a special console |
| # handle that if passed in lpAttributeList["handle_list"], will |
| # cause it to fail. |
| return list({handle for handle in handle_list |
| if handle & 0x3 != 0x3 |
| or _winapi.GetFileType(handle) != |
| _winapi.FILE_TYPE_CHAR}) |
| |
| |
| def _execute_child(self, args, executable, preexec_fn, close_fds, |
| pass_fds, cwd, env, |
| startupinfo, creationflags, shell, |
| p2cread, p2cwrite, |
| c2pread, c2pwrite, |
| errread, errwrite, |
| unused_restore_signals, unused_start_new_session): |
| """Execute program (MS Windows version)""" |
| |
| assert not pass_fds, "pass_fds not supported on Windows." |
| |
| if not isinstance(args, str): |
| args = list2cmdline(args) |
| |
| # Process startup details |
| if startupinfo is None: |
| startupinfo = STARTUPINFO() |
| else: |
| # bpo-34044: Copy STARTUPINFO since it is modified above, |
| # so the caller can reuse it multiple times. |
| startupinfo = startupinfo._copy() |
| |
| use_std_handles = -1 not in (p2cread, c2pwrite, errwrite) |
| if use_std_handles: |
| startupinfo.dwFlags |= _winapi.STARTF_USESTDHANDLES |
| startupinfo.hStdInput = p2cread |
| startupinfo.hStdOutput = c2pwrite |
| startupinfo.hStdError = errwrite |
| |
| attribute_list = startupinfo.lpAttributeList |
| have_handle_list = bool(attribute_list and |
| "handle_list" in attribute_list and |
| attribute_list["handle_list"]) |
| |
| # If we were given an handle_list or need to create one |
| if have_handle_list or (use_std_handles and close_fds): |
| if attribute_list is None: |
| attribute_list = startupinfo.lpAttributeList = {} |
| handle_list = attribute_list["handle_list"] = \ |
| list(attribute_list.get("handle_list", [])) |
| |
| if use_std_handles: |
| handle_list += [int(p2cread), int(c2pwrite), int(errwrite)] |
| |
| handle_list[:] = self._filter_handle_list(handle_list) |
| |
| if handle_list: |
| if not close_fds: |
| warnings.warn("startupinfo.lpAttributeList['handle_list'] " |
| "overriding close_fds", RuntimeWarning) |
| |
| # When using the handle_list we always request to inherit |
| # handles but the only handles that will be inherited are |
| # the ones in the handle_list |
| close_fds = False |
| |
| if shell: |
| startupinfo.dwFlags |= _winapi.STARTF_USESHOWWINDOW |
| startupinfo.wShowWindow = _winapi.SW_HIDE |
| comspec = os.environ.get("COMSPEC", "cmd.exe") |
| args = '{} /c "{}"'.format (comspec, args) |
| |
| # Start the process |
| try: |
| hp, ht, pid, tid = _winapi.CreateProcess(executable, args, |
| # no special security |
| None, None, |
| int(not close_fds), |
| creationflags, |
| env, |
| os.fspath(cwd) if cwd is not None else None, |
| startupinfo) |
| finally: |
| # Child is launched. Close the parent's copy of those pipe |
| # handles that only the child should have open. You need |
| # to make sure that no handles to the write end of the |
| # output pipe are maintained in this process or else the |
| # pipe will not close when the child process exits and the |
| # ReadFile will hang. |
| if p2cread != -1: |
| p2cread.Close() |
| if c2pwrite != -1: |
| c2pwrite.Close() |
| if errwrite != -1: |
| errwrite.Close() |
| if hasattr(self, '_devnull'): |
| os.close(self._devnull) |
| # Prevent a double close of these handles/fds from __init__ |
| # on error. |
| self._closed_child_pipe_fds = True |
| |
| # Retain the process handle, but close the thread handle |
| self._child_created = True |
| self._handle = Handle(hp) |
| self.pid = pid |
| _winapi.CloseHandle(ht) |
| |
| def _internal_poll(self, _deadstate=None, |
| _WaitForSingleObject=_winapi.WaitForSingleObject, |
| _WAIT_OBJECT_0=_winapi.WAIT_OBJECT_0, |
| _GetExitCodeProcess=_winapi.GetExitCodeProcess): |
| """Check if child process has terminated. Returns returncode |
| attribute. |
| |
| This method is called by __del__, so it can only refer to objects |
| in its local scope. |
| |
| """ |
| if self.returncode is None: |
| if _WaitForSingleObject(self._handle, 0) == _WAIT_OBJECT_0: |
| self.returncode = _GetExitCodeProcess(self._handle) |
| return self.returncode |
| |
| |
| def _wait(self, timeout): |
| """Internal implementation of wait() on Windows.""" |
| if timeout is None: |
| timeout_millis = _winapi.INFINITE |
| else: |
| timeout_millis = int(timeout * 1000) |
| if self.returncode is None: |
| # API note: Returns immediately if timeout_millis == 0. |
| result = _winapi.WaitForSingleObject(self._handle, |
| timeout_millis) |
| if result == _winapi.WAIT_TIMEOUT: |
| raise TimeoutExpired(self.args, timeout) |
| self.returncode = _winapi.GetExitCodeProcess(self._handle) |
| return self.returncode |
| |
| |
| def _readerthread(self, fh, buffer): |
| buffer.append(fh.read()) |
| fh.close() |
| |
| |
| def _communicate(self, input, endtime, orig_timeout): |
| # Start reader threads feeding into a list hanging off of this |
| # object, unless they've already been started. |
| if self.stdout and not hasattr(self, "_stdout_buff"): |
| self._stdout_buff = [] |
| self.stdout_thread = \ |
| threading.Thread(target=self._readerthread, |
| args=(self.stdout, self._stdout_buff)) |
| self.stdout_thread.daemon = True |
| self.stdout_thread.start() |
| if self.stderr and not hasattr(self, "_stderr_buff"): |
| self._stderr_buff = [] |
| self.stderr_thread = \ |
| threading.Thread(target=self._readerthread, |
| args=(self.stderr, self._stderr_buff)) |
| self.stderr_thread.daemon = True |
| self.stderr_thread.start() |
| |
| if self.stdin: |
| self._stdin_write(input) |
| |
| # Wait for the reader threads, or time out. If we time out, the |
| # threads remain reading and the fds left open in case the user |
| # calls communicate again. |
| if self.stdout is not None: |
| self.stdout_thread.join(self._remaining_time(endtime)) |
| if self.stdout_thread.is_alive(): |
| raise TimeoutExpired(self.args, orig_timeout) |
| if self.stderr is not None: |
| self.stderr_thread.join(self._remaining_time(endtime)) |
| if self.stderr_thread.is_alive(): |
| raise TimeoutExpired(self.args, orig_timeout) |
| |
| # Collect the output from and close both pipes, now that we know |
| # both have been read successfully. |
| stdout = None |
| stderr = None |
| if self.stdout: |
| stdout = self._stdout_buff |
| self.stdout.close() |
| if self.stderr: |
| stderr = self._stderr_buff |
| self.stderr.close() |
| |
| # All data exchanged. Translate lists into strings. |
| if stdout is not None: |
| stdout = stdout[0] |
| if stderr is not None: |
| stderr = stderr[0] |
| |
| return (stdout, stderr) |
| |
| def send_signal(self, sig): |
| """Send a signal to the process.""" |
| # Don't signal a process that we know has already died. |
| if self.returncode is not None: |
| return |
| if sig == signal.SIGTERM: |
| self.terminate() |
| elif sig == signal.CTRL_C_EVENT: |
| os.kill(self.pid, signal.CTRL_C_EVENT) |
| elif sig == signal.CTRL_BREAK_EVENT: |
| os.kill(self.pid, signal.CTRL_BREAK_EVENT) |
| else: |
| raise ValueError("Unsupported signal: {}".format(sig)) |
| |
| def terminate(self): |
| """Terminates the process.""" |
| # Don't terminate a process that we know has already died. |
| if self.returncode is not None: |
| return |
| try: |
| _winapi.TerminateProcess(self._handle, 1) |
| except PermissionError: |
| # ERROR_ACCESS_DENIED (winerror 5) is received when the |
| # process already died. |
| rc = _winapi.GetExitCodeProcess(self._handle) |
| if rc == _winapi.STILL_ACTIVE: |
| raise |
| self.returncode = rc |
| |
| kill = terminate |
| |
| else: |
| # |
| # POSIX methods |
| # |
| def _get_handles(self, stdin, stdout, stderr): |
| """Construct and return tuple with IO objects: |
| p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite |
| """ |
| p2cread, p2cwrite = -1, -1 |
| c2pread, c2pwrite = -1, -1 |
| errread, errwrite = -1, -1 |
| |
| if stdin is None: |
| pass |
| elif stdin == PIPE: |
| p2cread, p2cwrite = os.pipe() |
| elif stdin == DEVNULL: |
| p2cread = self._get_devnull() |
| elif isinstance(stdin, int): |
| p2cread = stdin |
| else: |
| # Assuming file-like object |
| p2cread = stdin.fileno() |
| |
| if stdout is None: |
| pass |
| elif stdout == PIPE: |
| c2pread, c2pwrite = os.pipe() |
| elif stdout == DEVNULL: |
| c2pwrite = self._get_devnull() |
| elif isinstance(stdout, int): |
| c2pwrite = stdout |
| else: |
| # Assuming file-like object |
| c2pwrite = stdout.fileno() |
| |
| if stderr is None: |
| pass |
| elif stderr == PIPE: |
| errread, errwrite = os.pipe() |
| elif stderr == STDOUT: |
| if c2pwrite != -1: |
| errwrite = c2pwrite |
| else: # child's stdout is not set, use parent's stdout |
| errwrite = sys.__stdout__.fileno() |
| elif stderr == DEVNULL: |
| errwrite = self._get_devnull() |
| elif isinstance(stderr, int): |
| errwrite = stderr |
| else: |
| # Assuming file-like object |
| errwrite = stderr.fileno() |
| |
| return (p2cread, p2cwrite, |
| c2pread, c2pwrite, |
| errread, errwrite) |
| |
| |
| def _execute_child(self, args, executable, preexec_fn, close_fds, |
| pass_fds, cwd, env, |
| startupinfo, creationflags, shell, |
| p2cread, p2cwrite, |
| c2pread, c2pwrite, |
| errread, errwrite, |
| restore_signals, start_new_session): |
| """Execute program (POSIX version)""" |
| |
| if isinstance(args, (str, bytes)): |
| args = [args] |
| else: |
| args = list(args) |
| |
| if shell: |
| # On Android the default shell is at '/system/bin/sh'. |
| unix_shell = ('/system/bin/sh' if |
| hasattr(sys, 'getandroidapilevel') else '/bin/sh') |
| args = [unix_shell, "-c"] + args |
| if executable: |
| args[0] = executable |
| |
| if executable is None: |
| executable = args[0] |
| orig_executable = executable |
| |
| # For transferring possible exec failure from child to parent. |
| # Data format: "exception name:hex errno:description" |
| # Pickle is not used; it is complex and involves memory allocation. |
| errpipe_read, errpipe_write = os.pipe() |
| # errpipe_write must not be in the standard io 0, 1, or 2 fd range. |
| low_fds_to_close = [] |
| while errpipe_write < 3: |
| low_fds_to_close.append(errpipe_write) |
| errpipe_write = os.dup(errpipe_write) |
| for low_fd in low_fds_to_close: |
| os.close(low_fd) |
| try: |
| try: |
| # We must avoid complex work that could involve |
| # malloc or free in the child process to avoid |
| # potential deadlocks, thus we do all this here. |
| # and pass it to fork_exec() |
| |
| if env is not None: |
| env_list = [] |
| for k, v in env.items(): |
| k = os.fsencode(k) |
| if b'=' in k: |
| raise ValueError("illegal environment variable name") |
| env_list.append(k + b'=' + os.fsencode(v)) |
| else: |
| env_list = None # Use execv instead of execve. |
| executable = os.fsencode(executable) |
| if os.path.dirname(executable): |
| executable_list = (executable,) |
| else: |
| # This matches the behavior of os._execvpe(). |
| executable_list = tuple( |
| os.path.join(os.fsencode(dir), executable) |
| for dir in os.get_exec_path(env)) |
| fds_to_keep = set(pass_fds) |
| fds_to_keep.add(errpipe_write) |
| self.pid = _posixsubprocess.fork_exec( |
| args, executable_list, |
| close_fds, tuple(sorted(map(int, fds_to_keep))), |
| cwd, env_list, |
| p2cread, p2cwrite, c2pread, c2pwrite, |
| errread, errwrite, |
| errpipe_read, errpipe_write, |
| restore_signals, start_new_session, preexec_fn) |
| self._child_created = True |
| finally: |
| # be sure the FD is closed no matter what |
| os.close(errpipe_write) |
| |
| # self._devnull is not always defined. |
| devnull_fd = getattr(self, '_devnull', None) |
| if p2cread != -1 and p2cwrite != -1 and p2cread != devnull_fd: |
| os.close(p2cread) |
| if c2pwrite != -1 and c2pread != -1 and c2pwrite != devnull_fd: |
| os.close(c2pwrite) |
| if errwrite != -1 and errread != -1 and errwrite != devnull_fd: |
| os.close(errwrite) |
| if devnull_fd is not None: |
| os.close(devnull_fd) |
| # Prevent a double close of these fds from __init__ on error. |
| self._closed_child_pipe_fds = True |
| |
| # Wait for exec to fail or succeed; possibly raising an |
| # exception (limited in size) |
| errpipe_data = bytearray() |
| while True: |
| part = os.read(errpipe_read, 50000) |
| errpipe_data += part |
| if not part or len(errpipe_data) > 50000: |
| break |
| finally: |
| # be sure the FD is closed no matter what |
| os.close(errpipe_read) |
| |
| if errpipe_data: |
| try: |
| pid, sts = os.waitpid(self.pid, 0) |
| if pid == self.pid: |
| self._handle_exitstatus(sts) |
| else: |
| self.returncode = sys.maxsize |
| except ChildProcessError: |
| pass |
| |
| try: |
| exception_name, hex_errno, err_msg = ( |
| errpipe_data.split(b':', 2)) |
| # The encoding here should match the encoding |
| # written in by the subprocess implementations |
| # like _posixsubprocess |
| err_msg = err_msg.decode() |
| except ValueError: |
| exception_name = b'SubprocessError' |
| hex_errno = b'0' |
| err_msg = 'Bad exception data from child: {!r}'.format( |
| bytes(errpipe_data)) |
| child_exception_type = getattr( |
| builtins, exception_name.decode('ascii'), |
| SubprocessError) |
| if issubclass(child_exception_type, OSError) and hex_errno: |
| errno_num = int(hex_errno, 16) |
| child_exec_never_called = (err_msg == "noexec") |
| if child_exec_never_called: |
| err_msg = "" |
| # The error must be from chdir(cwd). |
| err_filename = cwd |
| else: |
| err_filename = orig_executable |
| if errno_num != 0: |
| err_msg = os.strerror(errno_num) |
| if errno_num == errno.ENOENT: |
| err_msg += ': ' + repr(err_filename) |
| raise child_exception_type(errno_num, err_msg, err_filename) |
| raise child_exception_type(err_msg) |
| |
| |
| def _handle_exitstatus(self, sts, _WIFSIGNALED=os.WIFSIGNALED, |
| _WTERMSIG=os.WTERMSIG, _WIFEXITED=os.WIFEXITED, |
| _WEXITSTATUS=os.WEXITSTATUS, _WIFSTOPPED=os.WIFSTOPPED, |
| _WSTOPSIG=os.WSTOPSIG): |
| """All callers to this function MUST hold self._waitpid_lock.""" |
| # This method is called (indirectly) by __del__, so it cannot |
| # refer to anything outside of its local scope. |
| if _WIFSIGNALED(sts): |
| self.returncode = -_WTERMSIG(sts) |
| elif _WIFEXITED(sts): |
| self.returncode = _WEXITSTATUS(sts) |
| elif _WIFSTOPPED(sts): |
| self.returncode = -_WSTOPSIG(sts) |
| else: |
| # Should never happen |
| raise SubprocessError("Unknown child exit status!") |
| |
| |
| def _internal_poll(self, _deadstate=None, _waitpid=os.waitpid, |
| _WNOHANG=os.WNOHANG, _ECHILD=errno.ECHILD): |
| """Check if child process has terminated. Returns returncode |
| attribute. |
| |
| This method is called by __del__, so it cannot reference anything |
| outside of the local scope (nor can any methods it calls). |
| |
| """ |
| if self.returncode is None: |
| if not self._waitpid_lock.acquire(False): |
| # Something else is busy calling waitpid. Don't allow two |
| # at once. We know nothing yet. |
| return None |
| try: |
| if self.returncode is not None: |
| return self.returncode # Another thread waited. |
| pid, sts = _waitpid(self.pid, _WNOHANG) |
| if pid == self.pid: |
| self._handle_exitstatus(sts) |
| except OSError as e: |
| if _deadstate is not None: |
| self.returncode = _deadstate |
| elif e.errno == _ECHILD: |
| # This happens if SIGCLD is set to be ignored or |
| # waiting for child processes has otherwise been |
| # disabled for our process. This child is dead, we |
| # can't get the status. |
| # http://bugs.python.org/issue15756 |
| self.returncode = 0 |
| finally: |
| self._waitpid_lock.release() |
| return self.returncode |
| |
| |
| def _try_wait(self, wait_flags): |
| """All callers to this function MUST hold self._waitpid_lock.""" |
| try: |
| (pid, sts) = os.waitpid(self.pid, wait_flags) |
| except ChildProcessError: |
| # This happens if SIGCLD is set to be ignored or waiting |
| # for child processes has otherwise been disabled for our |
| # process. This child is dead, we can't get the status. |
| pid = self.pid |
| sts = 0 |
| return (pid, sts) |
| |
| |
| def _wait(self, timeout): |
| """Internal implementation of wait() on POSIX.""" |
| if self.returncode is not None: |
| return self.returncode |
| |
| if timeout is not None: |
| endtime = _time() + timeout |
| # Enter a busy loop if we have a timeout. This busy loop was |
| # cribbed from Lib/threading.py in Thread.wait() at r71065. |
| delay = 0.0005 # 500 us -> initial delay of 1 ms |
| while True: |
| if self._waitpid_lock.acquire(False): |
| try: |
| if self.returncode is not None: |
| break # Another thread waited. |
| (pid, sts) = self._try_wait(os.WNOHANG) |
| assert pid == self.pid or pid == 0 |
| if pid == self.pid: |
| self._handle_exitstatus(sts) |
| break |
| finally: |
| self._waitpid_lock.release() |
| remaining = self._remaining_time(endtime) |
| if remaining <= 0: |
| raise TimeoutExpired(self.args, timeout) |
| delay = min(delay * 2, remaining, .05) |
| time.sleep(delay) |
| else: |
| while self.returncode is None: |
| with self._waitpid_lock: |
| if self.returncode is not None: |
| break # Another thread waited. |
| (pid, sts) = self._try_wait(0) |
| # Check the pid and loop as waitpid has been known to |
| # return 0 even without WNOHANG in odd situations. |
| # http://bugs.python.org/issue14396. |
| if pid == self.pid: |
| self._handle_exitstatus(sts) |
| return self.returncode |
| |
| |
| def _communicate(self, input, endtime, orig_timeout): |
| if self.stdin and not self._communication_started: |
| # Flush stdio buffer. This might block, if the user has |
| # been writing to .stdin in an uncontrolled fashion. |
| try: |
| self.stdin.flush() |
| except BrokenPipeError: |
| pass # communicate() must ignore BrokenPipeError. |
| if not input: |
| try: |
| self.stdin.close() |
| except BrokenPipeError: |
| pass # communicate() must ignore BrokenPipeError. |
| |
| stdout = None |
| stderr = None |
| |
| # Only create this mapping if we haven't already. |
| if not self._communication_started: |
| self._fileobj2output = {} |
| if self.stdout: |
| self._fileobj2output[self.stdout] = [] |
| if self.stderr: |
| self._fileobj2output[self.stderr] = [] |
| |
| if self.stdout: |
| stdout = self._fileobj2output[self.stdout] |
| if self.stderr: |
| stderr = self._fileobj2output[self.stderr] |
| |
| self._save_input(input) |
| |
| if self._input: |
| input_view = memoryview(self._input) |
| |
| with _PopenSelector() as selector: |
| if self.stdin and input: |
| selector.register(self.stdin, selectors.EVENT_WRITE) |
| if self.stdout: |
| selector.register(self.stdout, selectors.EVENT_READ) |
| if self.stderr: |
| selector.register(self.stderr, selectors.EVENT_READ) |
| |
| while selector.get_map(): |
| timeout = self._remaining_time(endtime) |
| if timeout is not None and timeout < 0: |
| raise TimeoutExpired(self.args, orig_timeout) |
| |
| ready = selector.select(timeout) |
| self._check_timeout(endtime, orig_timeout) |
| |
| # XXX Rewrite these to use non-blocking I/O on the file |
| # objects; they are no longer using C stdio! |
| |
| for key, events in ready: |
| if key.fileobj is self.stdin: |
| chunk = input_view[self._input_offset : |
| self._input_offset + _PIPE_BUF] |
| try: |
| self._input_offset += os.write(key.fd, chunk) |
| except BrokenPipeError: |
| selector.unregister(key.fileobj) |
| key.fileobj.close() |
| else: |
| if self._input_offset >= len(self._input): |
| selector.unregister(key.fileobj) |
| key.fileobj.close() |
| elif key.fileobj in (self.stdout, self.stderr): |
| data = os.read(key.fd, 32768) |
| if not data: |
| selector.unregister(key.fileobj) |
| key.fileobj.close() |
| self._fileobj2output[key.fileobj].append(data) |
| |
| self.wait(timeout=self._remaining_time(endtime)) |
| |
| # All data exchanged. Translate lists into strings. |
| if stdout is not None: |
| stdout = b''.join(stdout) |
| if stderr is not None: |
| stderr = b''.join(stderr) |
| |
| # Translate newlines, if requested. |
| # This also turns bytes into strings. |
| if self.text_mode: |
| if stdout is not None: |
| stdout = self._translate_newlines(stdout, |
| self.stdout.encoding, |
| self.stdout.errors) |
| if stderr is not None: |
| stderr = self._translate_newlines(stderr, |
| self.stderr.encoding, |
| self.stderr.errors) |
| |
| return (stdout, stderr) |
| |
| |
| def _save_input(self, input): |
| # This method is called from the _communicate_with_*() methods |
| # so that if we time out while communicating, we can continue |
| # sending input if we retry. |
| if self.stdin and self._input is None: |
| self._input_offset = 0 |
| self._input = input |
| if input is not None and self.text_mode: |
| self._input = self._input.encode(self.stdin.encoding, |
| self.stdin.errors) |
| |
| |
| def send_signal(self, sig): |
| """Send a signal to the process.""" |
| # Skip signalling a process that we know has already died. |
| if self.returncode is None: |
| os.kill(self.pid, sig) |
| |
| def terminate(self): |
| """Terminate the process with SIGTERM |
| """ |
| self.send_signal(signal.SIGTERM) |
| |
| def kill(self): |
| """Kill the process with SIGKILL |
| """ |
| self.send_signal(signal.SIGKILL) |
