mirror of https://github.com/python/cpython
1761 lines
65 KiB
Python
1761 lines
65 KiB
Python
# subprocess - Subprocesses with accessible I/O streams
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#
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# For more information about this module, see PEP 324.
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#
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# Copyright (c) 2003-2005 by Peter Astrand <astrand@lysator.liu.se>
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#
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# Licensed to PSF under a Contributor Agreement.
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# See http://www.python.org/2.4/license for licensing details.
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r"""subprocess - Subprocesses with accessible I/O streams
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This module allows you to spawn processes, connect to their
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input/output/error pipes, and obtain their return codes. This module
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intends to replace several other, older modules and functions, like:
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os.system
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os.spawn*
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Information about how the subprocess module can be used to replace these
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modules and functions can be found below.
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Using the subprocess module
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===========================
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This module defines one class called Popen:
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class Popen(args, bufsize=0, executable=None,
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stdin=None, stdout=None, stderr=None,
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preexec_fn=None, close_fds=True, shell=False,
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cwd=None, env=None, universal_newlines=False,
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startupinfo=None, creationflags=0,
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restore_signals=True, start_new_session=False, pass_fds=()):
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Arguments are:
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args should be a string, or a sequence of program arguments. The
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program to execute is normally the first item in the args sequence or
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string, but can be explicitly set by using the executable argument.
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On POSIX, with shell=False (default): In this case, the Popen class
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uses os.execvp() to execute the child program. args should normally
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be a sequence. A string will be treated as a sequence with the string
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as the only item (the program to execute).
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On POSIX, with shell=True: If args is a string, it specifies the
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command string to execute through the shell. If args is a sequence,
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the first item specifies the command string, and any additional items
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will be treated as additional shell arguments.
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On Windows: the Popen class uses CreateProcess() to execute the child
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program, which operates on strings. If args is a sequence, it will be
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converted to a string using the list2cmdline method. Please note that
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not all MS Windows applications interpret the command line the same
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way: The list2cmdline is designed for applications using the same
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rules as the MS C runtime.
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bufsize, if given, has the same meaning as the corresponding argument
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to the built-in open() function: 0 means unbuffered, 1 means line
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buffered, any other positive value means use a buffer of
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(approximately) that size. A negative bufsize means to use the system
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default, which usually means fully buffered. The default value for
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bufsize is 0 (unbuffered).
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stdin, stdout and stderr specify the executed programs' standard
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input, standard output and standard error file handles, respectively.
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Valid values are PIPE, an existing file descriptor (a positive
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integer), an existing file object, and None. PIPE indicates that a
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new pipe to the child should be created. With None, no redirection
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will occur; the child's file handles will be inherited from the
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parent. Additionally, stderr can be STDOUT, which indicates that the
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stderr data from the applications should be captured into the same
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file handle as for stdout.
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On POSIX, if preexec_fn is set to a callable object, this object will be
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called in the child process just before the child is executed. The use
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of preexec_fn is not thread safe, using it in the presence of threads
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could lead to a deadlock in the child process before the new executable
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is executed.
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If close_fds is true, all file descriptors except 0, 1 and 2 will be
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closed before the child process is executed. The default for close_fds
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varies by platform: Always true on POSIX. True when stdin/stdout/stderr
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are None on Windows, false otherwise.
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pass_fds is an optional sequence of file descriptors to keep open between the
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parent and child. Providing any pass_fds implicitly sets close_fds to true.
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if shell is true, the specified command will be executed through the
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shell.
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If cwd is not None, the current directory will be changed to cwd
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before the child is executed.
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On POSIX, if restore_signals is True all signals that Python sets to
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SIG_IGN are restored to SIG_DFL in the child process before the exec.
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Currently this includes the SIGPIPE, SIGXFZ and SIGXFSZ signals. This
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parameter does nothing on Windows.
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On POSIX, if start_new_session is True, the setsid() system call will be made
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in the child process prior to executing the command.
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If env is not None, it defines the environment variables for the new
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process.
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If universal_newlines is true, the file objects stdout and stderr are
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opened as a text files, but lines may be terminated by any of '\n',
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the Unix end-of-line convention, '\r', the old Macintosh convention or
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'\r\n', the Windows convention. All of these external representations
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are seen as '\n' by the Python program. Note: This feature is only
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available if Python is built with universal newline support (the
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default). Also, the newlines attribute of the file objects stdout,
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stdin and stderr are not updated by the communicate() method.
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The startupinfo and creationflags, if given, will be passed to the
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underlying CreateProcess() function. They can specify things such as
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appearance of the main window and priority for the new process.
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(Windows only)
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This module also defines some shortcut functions:
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call(*popenargs, **kwargs):
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Run command with arguments. Wait for command to complete, then
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return the returncode attribute.
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The arguments are the same as for the Popen constructor. Example:
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>>> retcode = subprocess.call(["ls", "-l"])
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check_call(*popenargs, **kwargs):
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Run command with arguments. Wait for command to complete. If the
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exit code was zero then return, otherwise raise
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CalledProcessError. The CalledProcessError object will have the
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return code in the returncode attribute.
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The arguments are the same as for the Popen constructor. Example:
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>>> subprocess.check_call(["ls", "-l"])
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0
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getstatusoutput(cmd):
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Return (status, output) of executing cmd in a shell.
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Execute the string 'cmd' in a shell with os.popen() and return a 2-tuple
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(status, output). cmd is actually run as '{ cmd ; } 2>&1', so that the
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returned output will contain output or error messages. A trailing newline
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is stripped from the output. The exit status for the command can be
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interpreted according to the rules for the C function wait(). Example:
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>>> subprocess.getstatusoutput('ls /bin/ls')
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(0, '/bin/ls')
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>>> subprocess.getstatusoutput('cat /bin/junk')
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(256, 'cat: /bin/junk: No such file or directory')
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>>> subprocess.getstatusoutput('/bin/junk')
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(256, 'sh: /bin/junk: not found')
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getoutput(cmd):
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Return output (stdout or stderr) of executing cmd in a shell.
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Like getstatusoutput(), except the exit status is ignored and the return
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value is a string containing the command's output. Example:
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>>> subprocess.getoutput('ls /bin/ls')
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'/bin/ls'
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check_output(*popenargs, **kwargs):
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Run command with arguments and return its output as a byte string.
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If the exit code was non-zero it raises a CalledProcessError. The
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CalledProcessError object will have the return code in the returncode
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attribute and output in the output attribute.
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The arguments are the same as for the Popen constructor. Example:
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>>> output = subprocess.check_output(["ls", "-l", "/dev/null"])
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Exceptions
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----------
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Exceptions raised in the child process, before the new program has
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started to execute, will be re-raised in the parent. Additionally,
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the exception object will have one extra attribute called
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'child_traceback', which is a string containing traceback information
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from the childs point of view.
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The most common exception raised is OSError. This occurs, for
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example, when trying to execute a non-existent file. Applications
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should prepare for OSErrors.
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A ValueError will be raised if Popen is called with invalid arguments.
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Exceptions defined within this module inherit from SubprocessError.
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check_call() and check_output() will raise CalledProcessError if the
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called process returns a non-zero return code. TimeoutExpired
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be raised if a timeout was specified and expired.
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Security
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--------
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Unlike some other popen functions, this implementation will never call
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/bin/sh implicitly. This means that all characters, including shell
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metacharacters, can safely be passed to child processes.
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Popen objects
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=============
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Instances of the Popen class have the following methods:
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poll()
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Check if child process has terminated. Returns returncode
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attribute.
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wait()
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Wait for child process to terminate. Returns returncode attribute.
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communicate(input=None)
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Interact with process: Send data to stdin. Read data from stdout
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and stderr, until end-of-file is reached. Wait for process to
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terminate. The optional input argument should be a string to be
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sent to the child process, or None, if no data should be sent to
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the child.
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communicate() returns a tuple (stdout, stderr).
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Note: The data read is buffered in memory, so do not use this
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method if the data size is large or unlimited.
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The following attributes are also available:
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stdin
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If the stdin argument is PIPE, this attribute is a file object
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that provides input to the child process. Otherwise, it is None.
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stdout
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If the stdout argument is PIPE, this attribute is a file object
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that provides output from the child process. Otherwise, it is
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None.
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stderr
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If the stderr argument is PIPE, this attribute is file object that
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provides error output from the child process. Otherwise, it is
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None.
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pid
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The process ID of the child process.
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returncode
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The child return code. A None value indicates that the process
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hasn't terminated yet. A negative value -N indicates that the
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child was terminated by signal N (POSIX only).
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Replacing older functions with the subprocess module
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====================================================
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In this section, "a ==> b" means that b can be used as a replacement
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for a.
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Note: All functions in this section fail (more or less) silently if
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the executed program cannot be found; this module raises an OSError
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exception.
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In the following examples, we assume that the subprocess module is
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imported with "from subprocess import *".
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Replacing /bin/sh shell backquote
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---------------------------------
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output=`mycmd myarg`
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==>
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output = Popen(["mycmd", "myarg"], stdout=PIPE).communicate()[0]
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Replacing shell pipe line
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-------------------------
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output=`dmesg | grep hda`
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==>
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p1 = Popen(["dmesg"], stdout=PIPE)
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p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
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output = p2.communicate()[0]
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Replacing os.system()
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---------------------
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sts = os.system("mycmd" + " myarg")
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==>
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p = Popen("mycmd" + " myarg", shell=True)
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pid, sts = os.waitpid(p.pid, 0)
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Note:
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* Calling the program through the shell is usually not required.
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* It's easier to look at the returncode attribute than the
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exitstatus.
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A more real-world example would look like this:
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try:
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retcode = call("mycmd" + " myarg", shell=True)
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if retcode < 0:
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print("Child was terminated by signal", -retcode, file=sys.stderr)
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else:
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print("Child returned", retcode, file=sys.stderr)
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except OSError as e:
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print("Execution failed:", e, file=sys.stderr)
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Replacing os.spawn*
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-------------------
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P_NOWAIT example:
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pid = os.spawnlp(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg")
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==>
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pid = Popen(["/bin/mycmd", "myarg"]).pid
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P_WAIT example:
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retcode = os.spawnlp(os.P_WAIT, "/bin/mycmd", "mycmd", "myarg")
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==>
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retcode = call(["/bin/mycmd", "myarg"])
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Vector example:
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os.spawnvp(os.P_NOWAIT, path, args)
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==>
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Popen([path] + args[1:])
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Environment example:
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os.spawnlpe(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg", env)
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==>
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Popen(["/bin/mycmd", "myarg"], env={"PATH": "/usr/bin"})
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"""
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import sys
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mswindows = (sys.platform == "win32")
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import io
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import os
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import time
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import traceback
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import gc
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import signal
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import builtins
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import warnings
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# Exception classes used by this module.
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class SubprocessError(Exception): pass
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class CalledProcessError(SubprocessError):
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"""This exception is raised when a process run by check_call() or
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check_output() returns a non-zero exit status.
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The exit status will be stored in the returncode attribute;
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check_output() will also store the output in the output attribute.
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"""
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def __init__(self, returncode, cmd, output=None):
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self.returncode = returncode
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self.cmd = cmd
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self.output = output
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def __str__(self):
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return "Command '%s' returned non-zero exit status %d" % (self.cmd, self.returncode)
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class TimeoutExpired(SubprocessError):
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"""This exception is raised when the timeout expires while waiting for a
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child process.
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"""
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def __init__(self, cmd, output=None):
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self.cmd = cmd
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self.output = output
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def __str__(self):
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return ("Command '%s' timed out after %s seconds" %
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(self.cmd, self.timeout))
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if mswindows:
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import threading
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import msvcrt
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import _subprocess
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class STARTUPINFO:
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dwFlags = 0
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hStdInput = None
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hStdOutput = None
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hStdError = None
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wShowWindow = 0
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class pywintypes:
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error = IOError
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else:
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import select
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_has_poll = hasattr(select, 'poll')
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import errno
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import fcntl
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import pickle
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try:
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import _posixsubprocess
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except ImportError:
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_posixsubprocess = None
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warnings.warn("The _posixsubprocess module is not being used. "
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"Child process reliability may suffer if your "
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"program uses threads.", RuntimeWarning)
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# When select or poll has indicated that the file is writable,
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# we can write up to _PIPE_BUF bytes without risk of blocking.
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# POSIX defines PIPE_BUF as >= 512.
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_PIPE_BUF = getattr(select, 'PIPE_BUF', 512)
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_FD_CLOEXEC = getattr(fcntl, 'FD_CLOEXEC', 1)
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def _set_cloexec(fd, cloexec):
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old = fcntl.fcntl(fd, fcntl.F_GETFD)
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if cloexec:
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fcntl.fcntl(fd, fcntl.F_SETFD, old | _FD_CLOEXEC)
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else:
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fcntl.fcntl(fd, fcntl.F_SETFD, old & ~_FD_CLOEXEC)
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if _posixsubprocess:
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_create_pipe = _posixsubprocess.cloexec_pipe
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else:
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def _create_pipe():
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fds = os.pipe()
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_set_cloexec(fds[0], True)
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_set_cloexec(fds[1], True)
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return fds
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__all__ = ["Popen", "PIPE", "STDOUT", "call", "check_call", "getstatusoutput",
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"getoutput", "check_output", "CalledProcessError"]
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if mswindows:
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from _subprocess import CREATE_NEW_CONSOLE, CREATE_NEW_PROCESS_GROUP
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__all__.extend(["CREATE_NEW_CONSOLE", "CREATE_NEW_PROCESS_GROUP"])
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try:
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MAXFD = os.sysconf("SC_OPEN_MAX")
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except:
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MAXFD = 256
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_active = []
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def _cleanup():
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for inst in _active[:]:
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res = inst._internal_poll(_deadstate=sys.maxsize)
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if res is not None and res >= 0:
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try:
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_active.remove(inst)
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except ValueError:
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# This can happen if two threads create a new Popen instance.
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# It's harmless that it was already removed, so ignore.
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pass
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PIPE = -1
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STDOUT = -2
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def _eintr_retry_call(func, *args):
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while True:
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try:
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return func(*args)
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except OSError as e:
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if e.errno == errno.EINTR:
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continue
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raise
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def call(*popenargs, timeout=None, **kwargs):
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"""Run command with arguments. Wait for command to complete or
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timeout, then return the returncode attribute.
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The arguments are the same as for the Popen constructor. Example:
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retcode = call(["ls", "-l"])
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"""
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p = Popen(*popenargs, **kwargs)
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try:
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return p.wait(timeout=timeout)
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except TimeoutExpired:
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p.kill()
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p.wait()
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raise
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def check_call(*popenargs, **kwargs):
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"""Run command with arguments. Wait for command to complete. If
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the exit code was zero then return, otherwise raise
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CalledProcessError. The CalledProcessError object will have the
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return code in the returncode attribute.
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The arguments are the same as for the call function. Example:
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check_call(["ls", "-l"])
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"""
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retcode = call(*popenargs, **kwargs)
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if retcode:
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cmd = kwargs.get("args")
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if cmd is None:
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cmd = popenargs[0]
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raise CalledProcessError(retcode, cmd)
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return 0
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def check_output(*popenargs, timeout=None, **kwargs):
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r"""Run command with arguments and return its output as a byte string.
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If the exit code was non-zero it raises a CalledProcessError. The
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CalledProcessError object will have the return code in the returncode
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attribute and output in the output attribute.
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The arguments are the same as for the Popen constructor. Example:
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>>> check_output(["ls", "-l", "/dev/null"])
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b'crw-rw-rw- 1 root root 1, 3 Oct 18 2007 /dev/null\n'
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The stdout argument is not allowed as it is used internally.
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To capture standard error in the result, use stderr=STDOUT.
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>>> check_output(["/bin/sh", "-c",
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... "ls -l non_existent_file ; exit 0"],
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... stderr=STDOUT)
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b'ls: non_existent_file: No such file or directory\n'
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"""
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if 'stdout' in kwargs:
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raise ValueError('stdout argument not allowed, it will be overridden.')
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process = Popen(*popenargs, stdout=PIPE, **kwargs)
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try:
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output, unused_err = process.communicate(timeout=timeout)
|
|
except TimeoutExpired:
|
|
process.kill()
|
|
output, unused_err = process.communicate()
|
|
raise TimeoutExpired(process.args, output=output)
|
|
retcode = process.poll()
|
|
if retcode:
|
|
raise CalledProcessError(retcode, process.args, output=output)
|
|
return output
|
|
|
|
|
|
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.
|
|
#
|
|
# NB This only works (and is only relevant) for POSIX.
|
|
|
|
def getstatusoutput(cmd):
|
|
"""Return (status, output) of executing cmd in a shell.
|
|
|
|
Execute the string 'cmd' in a shell with os.popen() and return a 2-tuple
|
|
(status, output). cmd is actually run as '{ cmd ; } 2>&1', so that the
|
|
returned output will contain output or error messages. A trailing newline
|
|
is stripped from the output. The exit status for the command can be
|
|
interpreted according to the rules for the C function wait(). Example:
|
|
|
|
>>> import subprocess
|
|
>>> subprocess.getstatusoutput('ls /bin/ls')
|
|
(0, '/bin/ls')
|
|
>>> subprocess.getstatusoutput('cat /bin/junk')
|
|
(256, 'cat: /bin/junk: No such file or directory')
|
|
>>> subprocess.getstatusoutput('/bin/junk')
|
|
(256, 'sh: /bin/junk: not found')
|
|
"""
|
|
pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r')
|
|
text = pipe.read()
|
|
sts = pipe.close()
|
|
if sts is None: sts = 0
|
|
if text[-1:] == '\n': text = text[:-1]
|
|
return sts, text
|
|
|
|
|
|
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]
|
|
|
|
|
|
_PLATFORM_DEFAULT_CLOSE_FDS = object()
|
|
|
|
|
|
class Popen(object):
|
|
def __init__(self, args, bufsize=0, executable=None,
|
|
stdin=None, stdout=None, stderr=None,
|
|
preexec_fn=None, close_fds=_PLATFORM_DEFAULT_CLOSE_FDS,
|
|
shell=False, cwd=None, env=None, universal_newlines=False,
|
|
startupinfo=None, creationflags=0,
|
|
restore_signals=True, start_new_session=False,
|
|
pass_fds=()):
|
|
"""Create new Popen instance."""
|
|
_cleanup()
|
|
|
|
self._child_created = False
|
|
self._input = None
|
|
self._communication_started = False
|
|
if bufsize is None:
|
|
bufsize = 0 # 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")
|
|
any_stdio_set = (stdin is not None or stdout is not None or
|
|
stderr is not None)
|
|
if close_fds is _PLATFORM_DEFAULT_CLOSE_FDS:
|
|
if any_stdio_set:
|
|
close_fds = False
|
|
else:
|
|
close_fds = True
|
|
elif close_fds and any_stdio_set:
|
|
raise ValueError(
|
|
"close_fds is not supported on Windows platforms"
|
|
" if you redirect stdin/stdout/stderr")
|
|
else:
|
|
# POSIX
|
|
if close_fds is _PLATFORM_DEFAULT_CLOSE_FDS:
|
|
close_fds = True
|
|
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.universal_newlines = universal_newlines
|
|
|
|
# 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)
|
|
|
|
if bufsize == 0:
|
|
bufsize = 1 # Nearly unbuffered (XXX for now)
|
|
if p2cwrite != -1:
|
|
self.stdin = io.open(p2cwrite, 'wb', bufsize)
|
|
if self.universal_newlines:
|
|
self.stdin = io.TextIOWrapper(self.stdin)
|
|
if c2pread != -1:
|
|
self.stdout = io.open(c2pread, 'rb', bufsize)
|
|
if universal_newlines:
|
|
self.stdout = io.TextIOWrapper(self.stdout)
|
|
if errread != -1:
|
|
self.stderr = io.open(errread, 'rb', bufsize)
|
|
if universal_newlines:
|
|
self.stderr = io.TextIOWrapper(self.stderr)
|
|
|
|
try:
|
|
self._execute_child(args, executable, preexec_fn, close_fds,
|
|
pass_fds, cwd, env, universal_newlines,
|
|
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 EnvironmentError:
|
|
# Ignore EBADF or other errors
|
|
pass
|
|
raise
|
|
|
|
|
|
def _translate_newlines(self, data, encoding):
|
|
data = data.replace(b"\r\n", b"\n").replace(b"\r", b"\n")
|
|
return data.decode(encoding)
|
|
|
|
def __enter__(self):
|
|
return self
|
|
|
|
def __exit__(self, type, value, traceback):
|
|
if self.stdout:
|
|
self.stdout.close()
|
|
if self.stderr:
|
|
self.stderr.close()
|
|
if self.stdin:
|
|
self.stdin.close()
|
|
|
|
def __del__(self, _maxsize=sys.maxsize, _active=_active):
|
|
if not self._child_created:
|
|
# We didn't get to successfully create a child process.
|
|
return
|
|
# 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 communicate(self, input=None, timeout=None):
|
|
"""Interact with process: Send data to stdin. Read data from
|
|
stdout and stderr, until end-of-file is reached. Wait for
|
|
process to terminate. The optional input argument should be a
|
|
string to be sent to the child process, or None, if no data
|
|
should be sent to the child.
|
|
|
|
communicate() returns a tuple (stdout, stderr)."""
|
|
|
|
if self._communication_started and input:
|
|
raise ValueError("Cannot send input after starting communication")
|
|
|
|
if timeout is not None:
|
|
endtime = time.time() + timeout
|
|
else:
|
|
endtime = None
|
|
|
|
# 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 (endtime is None and not self._communication_started and
|
|
[self.stdin, self.stdout, self.stderr].count(None) >= 2):
|
|
stdout = None
|
|
stderr = None
|
|
if self.stdin:
|
|
if input:
|
|
self.stdin.write(input)
|
|
self.stdin.close()
|
|
elif self.stdout:
|
|
stdout = self.stdout.read()
|
|
self.stdout.close()
|
|
elif self.stderr:
|
|
stderr = self.stderr.read()
|
|
self.stderr.close()
|
|
self.wait()
|
|
return (stdout, stderr)
|
|
|
|
try:
|
|
stdout, stderr = self._communicate(input, endtime)
|
|
finally:
|
|
self._communication_started = True
|
|
|
|
sts = self.wait(timeout=self._remaining_time(endtime))
|
|
|
|
return (stdout, stderr)
|
|
|
|
|
|
def poll(self):
|
|
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.time()
|
|
|
|
|
|
def _check_timeout(self, endtime):
|
|
"""Convenience for checking if a timeout has expired."""
|
|
if endtime is None:
|
|
return
|
|
if time.time() > endtime:
|
|
raise TimeoutExpired(self.args)
|
|
|
|
|
|
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 = _subprocess.GetStdHandle(_subprocess.STD_INPUT_HANDLE)
|
|
if p2cread is None:
|
|
p2cread, _ = _subprocess.CreatePipe(None, 0)
|
|
elif stdin == PIPE:
|
|
p2cread, p2cwrite = _subprocess.CreatePipe(None, 0)
|
|
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 = _subprocess.GetStdHandle(_subprocess.STD_OUTPUT_HANDLE)
|
|
if c2pwrite is None:
|
|
_, c2pwrite = _subprocess.CreatePipe(None, 0)
|
|
elif stdout == PIPE:
|
|
c2pread, c2pwrite = _subprocess.CreatePipe(None, 0)
|
|
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 = _subprocess.GetStdHandle(_subprocess.STD_ERROR_HANDLE)
|
|
if errwrite is None:
|
|
_, errwrite = _subprocess.CreatePipe(None, 0)
|
|
elif stderr == PIPE:
|
|
errread, errwrite = _subprocess.CreatePipe(None, 0)
|
|
elif stderr == STDOUT:
|
|
errwrite = c2pwrite
|
|
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"""
|
|
return _subprocess.DuplicateHandle(_subprocess.GetCurrentProcess(),
|
|
handle, _subprocess.GetCurrentProcess(), 0, 1,
|
|
_subprocess.DUPLICATE_SAME_ACCESS)
|
|
|
|
|
|
def _find_w9xpopen(self):
|
|
"""Find and return absolut path to w9xpopen.exe"""
|
|
w9xpopen = os.path.join(
|
|
os.path.dirname(_subprocess.GetModuleFileName(0)),
|
|
"w9xpopen.exe")
|
|
if not os.path.exists(w9xpopen):
|
|
# Eeek - file-not-found - possibly an embedding
|
|
# situation - see if we can locate it in sys.exec_prefix
|
|
w9xpopen = os.path.join(os.path.dirname(sys.exec_prefix),
|
|
"w9xpopen.exe")
|
|
if not os.path.exists(w9xpopen):
|
|
raise RuntimeError("Cannot locate w9xpopen.exe, which is "
|
|
"needed for Popen to work with your "
|
|
"shell or platform.")
|
|
return w9xpopen
|
|
|
|
|
|
def _execute_child(self, args, executable, preexec_fn, close_fds,
|
|
pass_fds, cwd, env, universal_newlines,
|
|
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()
|
|
if -1 not in (p2cread, c2pwrite, errwrite):
|
|
startupinfo.dwFlags |= _subprocess.STARTF_USESTDHANDLES
|
|
startupinfo.hStdInput = p2cread
|
|
startupinfo.hStdOutput = c2pwrite
|
|
startupinfo.hStdError = errwrite
|
|
|
|
if shell:
|
|
startupinfo.dwFlags |= _subprocess.STARTF_USESHOWWINDOW
|
|
startupinfo.wShowWindow = _subprocess.SW_HIDE
|
|
comspec = os.environ.get("COMSPEC", "cmd.exe")
|
|
args = '{} /c "{}"'.format (comspec, args)
|
|
if (_subprocess.GetVersion() >= 0x80000000 or
|
|
os.path.basename(comspec).lower() == "command.com"):
|
|
# Win9x, or using command.com on NT. We need to
|
|
# use the w9xpopen intermediate program. For more
|
|
# information, see KB Q150956
|
|
# (http://web.archive.org/web/20011105084002/http://support.microsoft.com/support/kb/articles/Q150/9/56.asp)
|
|
w9xpopen = self._find_w9xpopen()
|
|
args = '"%s" %s' % (w9xpopen, args)
|
|
# Not passing CREATE_NEW_CONSOLE has been known to
|
|
# cause random failures on win9x. Specifically a
|
|
# dialog: "Your program accessed mem currently in
|
|
# use at xxx" and a hopeful warning about the
|
|
# stability of your system. Cost is Ctrl+C won't
|
|
# kill children.
|
|
creationflags |= _subprocess.CREATE_NEW_CONSOLE
|
|
|
|
# Start the process
|
|
try:
|
|
hp, ht, pid, tid = _subprocess.CreateProcess(executable, args,
|
|
# no special security
|
|
None, None,
|
|
int(not close_fds),
|
|
creationflags,
|
|
env,
|
|
cwd,
|
|
startupinfo)
|
|
except pywintypes.error as e:
|
|
# Translate pywintypes.error to WindowsError, which is
|
|
# a subclass of OSError. FIXME: We should really
|
|
# translate errno using _sys_errlist (or simliar), but
|
|
# how can this be done from Python?
|
|
raise WindowsError(*e.args)
|
|
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()
|
|
|
|
# Retain the process handle, but close the thread handle
|
|
self._child_created = True
|
|
self._handle = hp
|
|
self.pid = pid
|
|
ht.Close()
|
|
|
|
def _internal_poll(self, _deadstate=None,
|
|
_WaitForSingleObject=_subprocess.WaitForSingleObject,
|
|
_WAIT_OBJECT_0=_subprocess.WAIT_OBJECT_0,
|
|
_GetExitCodeProcess=_subprocess.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=None):
|
|
"""Wait for child process to terminate. Returns returncode
|
|
attribute."""
|
|
if timeout is None:
|
|
timeout = _subprocess.INFINITE
|
|
else:
|
|
timeout = int(timeout * 1000)
|
|
if self.returncode is None:
|
|
result = _subprocess.WaitForSingleObject(self._handle, timeout)
|
|
if result == _subprocess.WAIT_TIMEOUT:
|
|
raise TimeoutExpired(self.args)
|
|
self.returncode = _subprocess.GetExitCodeProcess(self._handle)
|
|
return self.returncode
|
|
|
|
|
|
def _readerthread(self, fh, buffer):
|
|
buffer.append(fh.read())
|
|
fh.close()
|
|
|
|
|
|
def _communicate(self, input, endtime):
|
|
# 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:
|
|
if input is not None:
|
|
self.stdin.write(input)
|
|
self.stdin.close()
|
|
|
|
# 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.isAlive():
|
|
raise TimeoutExpired(self.args)
|
|
if self.stderr is not None:
|
|
self.stderr_thread.join(self._remaining_time(endtime))
|
|
if self.stderr_thread.isAlive():
|
|
raise TimeoutExpired(self.args)
|
|
|
|
# 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
|
|
"""
|
|
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
|
|
"""
|
|
_subprocess.TerminateProcess(self._handle, 1)
|
|
|
|
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 = _create_pipe()
|
|
elif isinstance(stdin, int):
|
|
p2cread = stdin
|
|
else:
|
|
# Assuming file-like object
|
|
p2cread = stdin.fileno()
|
|
|
|
if stdout is None:
|
|
pass
|
|
elif stdout == PIPE:
|
|
c2pread, c2pwrite = _create_pipe()
|
|
elif isinstance(stdout, int):
|
|
c2pwrite = stdout
|
|
else:
|
|
# Assuming file-like object
|
|
c2pwrite = stdout.fileno()
|
|
|
|
if stderr is None:
|
|
pass
|
|
elif stderr == PIPE:
|
|
errread, errwrite = _create_pipe()
|
|
elif stderr == STDOUT:
|
|
errwrite = c2pwrite
|
|
elif isinstance(stderr, int):
|
|
errwrite = stderr
|
|
else:
|
|
# Assuming file-like object
|
|
errwrite = stderr.fileno()
|
|
|
|
return (p2cread, p2cwrite,
|
|
c2pread, c2pwrite,
|
|
errread, errwrite)
|
|
|
|
|
|
def _close_fds(self, fds_to_keep):
|
|
start_fd = 3
|
|
for fd in sorted(fds_to_keep):
|
|
if fd >= start_fd:
|
|
os.closerange(start_fd, fd)
|
|
start_fd = fd + 1
|
|
if start_fd <= MAXFD:
|
|
os.closerange(start_fd, MAXFD)
|
|
|
|
|
|
def _execute_child(self, args, executable, preexec_fn, close_fds,
|
|
pass_fds, cwd, env, universal_newlines,
|
|
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:
|
|
args = ["/bin/sh", "-c"] + args
|
|
if executable:
|
|
args[0] = executable
|
|
|
|
if executable is None:
|
|
executable = args[0]
|
|
|
|
# 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 = _create_pipe()
|
|
try:
|
|
try:
|
|
|
|
if _posixsubprocess:
|
|
# 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:
|
|
env_list = [os.fsencode(k) + b'=' + os.fsencode(v)
|
|
for k, v in env.items()]
|
|
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, sorted(fds_to_keep), cwd, env_list,
|
|
p2cread, p2cwrite, c2pread, c2pwrite,
|
|
errread, errwrite,
|
|
errpipe_read, errpipe_write,
|
|
restore_signals, start_new_session, preexec_fn)
|
|
else:
|
|
# Pure Python implementation: It is not thread safe.
|
|
# This implementation may deadlock in the child if your
|
|
# parent process has any other threads running.
|
|
|
|
gc_was_enabled = gc.isenabled()
|
|
# Disable gc to avoid bug where gc -> file_dealloc ->
|
|
# write to stderr -> hang. See issue1336
|
|
gc.disable()
|
|
try:
|
|
self.pid = os.fork()
|
|
except:
|
|
if gc_was_enabled:
|
|
gc.enable()
|
|
raise
|
|
self._child_created = True
|
|
if self.pid == 0:
|
|
# Child
|
|
try:
|
|
# Close parent's pipe ends
|
|
if p2cwrite != -1:
|
|
os.close(p2cwrite)
|
|
if c2pread != -1:
|
|
os.close(c2pread)
|
|
if errread != -1:
|
|
os.close(errread)
|
|
os.close(errpipe_read)
|
|
|
|
# Dup fds for child
|
|
def _dup2(a, b):
|
|
# dup2() removes the CLOEXEC flag but
|
|
# we must do it ourselves if dup2()
|
|
# would be a no-op (issue #10806).
|
|
if a == b:
|
|
_set_cloexec(a, False)
|
|
elif a != -1:
|
|
os.dup2(a, b)
|
|
_dup2(p2cread, 0)
|
|
_dup2(c2pwrite, 1)
|
|
_dup2(errwrite, 2)
|
|
|
|
# Close pipe fds. Make sure we don't close the
|
|
# same fd more than once, or standard fds.
|
|
closed = set()
|
|
for fd in [p2cread, c2pwrite, errwrite]:
|
|
if fd > 2 and fd not in closed:
|
|
os.close(fd)
|
|
closed.add(fd)
|
|
|
|
# Close all other fds, if asked for
|
|
if close_fds:
|
|
fds_to_keep = set(pass_fds)
|
|
fds_to_keep.add(errpipe_write)
|
|
self._close_fds(fds_to_keep)
|
|
|
|
|
|
if cwd is not None:
|
|
os.chdir(cwd)
|
|
|
|
# This is a copy of Python/pythonrun.c
|
|
# _Py_RestoreSignals(). If that were exposed
|
|
# as a sys._py_restoresignals func it would be
|
|
# better.. but this pure python implementation
|
|
# isn't likely to be used much anymore.
|
|
if restore_signals:
|
|
signals = ('SIGPIPE', 'SIGXFZ', 'SIGXFSZ')
|
|
for sig in signals:
|
|
if hasattr(signal, sig):
|
|
signal.signal(getattr(signal, sig),
|
|
signal.SIG_DFL)
|
|
|
|
if start_new_session and hasattr(os, 'setsid'):
|
|
os.setsid()
|
|
|
|
if preexec_fn:
|
|
preexec_fn()
|
|
|
|
if env is None:
|
|
os.execvp(executable, args)
|
|
else:
|
|
os.execvpe(executable, args, env)
|
|
|
|
except:
|
|
try:
|
|
exc_type, exc_value = sys.exc_info()[:2]
|
|
if isinstance(exc_value, OSError):
|
|
errno_num = exc_value.errno
|
|
else:
|
|
errno_num = 0
|
|
message = '%s:%x:%s' % (exc_type.__name__,
|
|
errno_num, exc_value)
|
|
message = message.encode(errors="surrogatepass")
|
|
os.write(errpipe_write, message)
|
|
except Exception:
|
|
# We MUST not allow anything odd happening
|
|
# above to prevent us from exiting below.
|
|
pass
|
|
|
|
# This exitcode won't be reported to applications
|
|
# so it really doesn't matter what we return.
|
|
os._exit(255)
|
|
|
|
# Parent
|
|
if gc_was_enabled:
|
|
gc.enable()
|
|
finally:
|
|
# be sure the FD is closed no matter what
|
|
os.close(errpipe_write)
|
|
|
|
if p2cread != -1 and p2cwrite != -1:
|
|
os.close(p2cread)
|
|
if c2pwrite != -1 and c2pread != -1:
|
|
os.close(c2pwrite)
|
|
if errwrite != -1 and errread != -1:
|
|
os.close(errwrite)
|
|
|
|
# Wait for exec to fail or succeed; possibly raising an
|
|
# exception (limited in size)
|
|
data = bytearray()
|
|
while True:
|
|
part = _eintr_retry_call(os.read, errpipe_read, 50000)
|
|
data += part
|
|
if not part or len(data) > 50000:
|
|
break
|
|
finally:
|
|
# be sure the FD is closed no matter what
|
|
os.close(errpipe_read)
|
|
|
|
if data:
|
|
try:
|
|
_eintr_retry_call(os.waitpid, self.pid, 0)
|
|
except OSError as e:
|
|
if e.errno != errno.ECHILD:
|
|
raise
|
|
try:
|
|
exception_name, hex_errno, err_msg = data.split(b':', 2)
|
|
except ValueError:
|
|
print('Bad exception data:', repr(data))
|
|
exception_name = b'RuntimeError'
|
|
hex_errno = b'0'
|
|
err_msg = b'Unknown'
|
|
child_exception_type = getattr(
|
|
builtins, exception_name.decode('ascii'),
|
|
RuntimeError)
|
|
for fd in (p2cwrite, c2pread, errread):
|
|
if fd != -1:
|
|
os.close(fd)
|
|
err_msg = err_msg.decode(errors="surrogatepass")
|
|
if issubclass(child_exception_type, OSError) and hex_errno:
|
|
errno_num = int(hex_errno, 16)
|
|
if errno_num != 0:
|
|
err_msg = os.strerror(errno_num)
|
|
if errno_num == errno.ENOENT:
|
|
err_msg += ': ' + repr(args[0])
|
|
raise child_exception_type(errno_num, err_msg)
|
|
raise child_exception_type(err_msg)
|
|
|
|
|
|
def _handle_exitstatus(self, sts, _WIFSIGNALED=os.WIFSIGNALED,
|
|
_WTERMSIG=os.WTERMSIG, _WIFEXITED=os.WIFEXITED,
|
|
_WEXITSTATUS=os.WEXITSTATUS):
|
|
# 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)
|
|
else:
|
|
# Should never happen
|
|
raise RuntimeError("Unknown child exit status!")
|
|
|
|
|
|
def _internal_poll(self, _deadstate=None, _waitpid=os.waitpid,
|
|
_WNOHANG=os.WNOHANG, _os_error=os.error):
|
|
"""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:
|
|
try:
|
|
pid, sts = _waitpid(self.pid, _WNOHANG)
|
|
if pid == self.pid:
|
|
self._handle_exitstatus(sts)
|
|
except _os_error:
|
|
if _deadstate is not None:
|
|
self.returncode = _deadstate
|
|
return self.returncode
|
|
|
|
|
|
def _try_wait(self, wait_flags):
|
|
try:
|
|
(pid, sts) = _eintr_retry_call(os.waitpid, self.pid, wait_flags)
|
|
except OSError as e:
|
|
if e.errno != errno.ECHILD:
|
|
raise
|
|
# 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=None, endtime=None):
|
|
"""Wait for child process to terminate. Returns returncode
|
|
attribute."""
|
|
# If timeout was passed but not endtime, compute endtime in terms of
|
|
# timeout.
|
|
if endtime is None and timeout is not None:
|
|
endtime = time.time() + timeout
|
|
if self.returncode is not None:
|
|
return self.returncode
|
|
elif endtime is not None:
|
|
# 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:
|
|
(pid, sts) = self._try_wait(os.WNOHANG)
|
|
assert pid == self.pid or pid == 0
|
|
if pid == self.pid:
|
|
self._handle_exitstatus(sts)
|
|
break
|
|
remaining = self._remaining_time(endtime)
|
|
if remaining <= 0:
|
|
raise TimeoutExpired(self.args)
|
|
delay = min(delay * 2, remaining, .05)
|
|
time.sleep(delay)
|
|
elif self.returncode is None:
|
|
(pid, sts) = self._try_wait(0)
|
|
self._handle_exitstatus(sts)
|
|
return self.returncode
|
|
|
|
|
|
def _communicate(self, input, endtime):
|
|
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.
|
|
self.stdin.flush()
|
|
if not input:
|
|
self.stdin.close()
|
|
|
|
if _has_poll:
|
|
stdout, stderr = self._communicate_with_poll(input, endtime)
|
|
else:
|
|
stdout, stderr = self._communicate_with_select(input, endtime)
|
|
|
|
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.universal_newlines:
|
|
if stdout is not None:
|
|
stdout = self._translate_newlines(stdout,
|
|
self.stdout.encoding)
|
|
if stderr is not None:
|
|
stderr = self._translate_newlines(stderr,
|
|
self.stderr.encoding)
|
|
|
|
return (stdout, stderr)
|
|
|
|
|
|
def _communicate_with_poll(self, input, endtime):
|
|
stdout = None # Return
|
|
stderr = None # Return
|
|
|
|
if not self._communication_started:
|
|
self._fd2file = {}
|
|
|
|
poller = select.poll()
|
|
def register_and_append(file_obj, eventmask):
|
|
poller.register(file_obj.fileno(), eventmask)
|
|
self._fd2file[file_obj.fileno()] = file_obj
|
|
|
|
def close_unregister_and_remove(fd):
|
|
poller.unregister(fd)
|
|
self._fd2file[fd].close()
|
|
self._fd2file.pop(fd)
|
|
|
|
if self.stdin and input:
|
|
register_and_append(self.stdin, select.POLLOUT)
|
|
|
|
# Only create this mapping if we haven't already.
|
|
if not self._communication_started:
|
|
self._fd2output = {}
|
|
if self.stdout:
|
|
self._fd2output[self.stdout.fileno()] = []
|
|
if self.stderr:
|
|
self._fd2output[self.stderr.fileno()] = []
|
|
|
|
select_POLLIN_POLLPRI = select.POLLIN | select.POLLPRI
|
|
if self.stdout:
|
|
register_and_append(self.stdout, select_POLLIN_POLLPRI)
|
|
stdout = self._fd2output[self.stdout.fileno()]
|
|
if self.stderr:
|
|
register_and_append(self.stderr, select_POLLIN_POLLPRI)
|
|
stderr = self._fd2output[self.stderr.fileno()]
|
|
|
|
# Save the input here 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 self.universal_newlines:
|
|
self._input = self._input.encode(self.stdin.encoding)
|
|
|
|
while self._fd2file:
|
|
try:
|
|
ready = poller.poll(self._remaining_time(endtime))
|
|
except select.error as e:
|
|
if e.args[0] == errno.EINTR:
|
|
continue
|
|
raise
|
|
self._check_timeout(endtime)
|
|
|
|
# XXX Rewrite these to use non-blocking I/O on the
|
|
# file objects; they are no longer using C stdio!
|
|
|
|
for fd, mode in ready:
|
|
if mode & select.POLLOUT:
|
|
chunk = self._input[self._input_offset :
|
|
self._input_offset + _PIPE_BUF]
|
|
self._input_offset += os.write(fd, chunk)
|
|
if self._input_offset >= len(self._input):
|
|
close_unregister_and_remove(fd)
|
|
elif mode & select_POLLIN_POLLPRI:
|
|
data = os.read(fd, 4096)
|
|
if not data:
|
|
close_unregister_and_remove(fd)
|
|
self._fd2output[fd].append(data)
|
|
else:
|
|
# Ignore hang up or errors.
|
|
close_unregister_and_remove(fd)
|
|
|
|
return (stdout, stderr)
|
|
|
|
|
|
def _communicate_with_select(self, input, endtime):
|
|
if not self._communication_started:
|
|
self._read_set = []
|
|
self._write_set = []
|
|
if self.stdin and input:
|
|
self._write_set.append(self.stdin)
|
|
if self.stdout:
|
|
self._read_set.append(self.stdout)
|
|
if self.stderr:
|
|
self._read_set.append(self.stderr)
|
|
|
|
if self.stdin and self._input is None:
|
|
self._input_offset = 0
|
|
self._input = input
|
|
if self.universal_newlines:
|
|
self._input = self._input.encode(self.stdin.encoding)
|
|
|
|
stdout = None # Return
|
|
stderr = None # Return
|
|
|
|
if self.stdout:
|
|
if not self._communication_started:
|
|
self._stdout_buff = []
|
|
stdout = self._stdout_buff
|
|
if self.stderr:
|
|
if not self._communication_started:
|
|
self._stderr_buff = []
|
|
stderr = self._stderr_buff
|
|
|
|
while self._read_set or self._write_set:
|
|
try:
|
|
(rlist, wlist, xlist) = \
|
|
select.select(self._read_set, self._write_set, [],
|
|
self._remaining_time(endtime))
|
|
except select.error as e:
|
|
if e.args[0] == errno.EINTR:
|
|
continue
|
|
raise
|
|
|
|
# According to the docs, returning three empty lists indicates
|
|
# that the timeout expired.
|
|
if not (rlist or wlist or xlist):
|
|
raise TimeoutExpired(self.args)
|
|
# We also check what time it is ourselves for good measure.
|
|
self._check_timeout(endtime)
|
|
|
|
# XXX Rewrite these to use non-blocking I/O on the
|
|
# file objects; they are no longer using C stdio!
|
|
|
|
if self.stdin in wlist:
|
|
chunk = self._input[self._input_offset :
|
|
self._input_offset + _PIPE_BUF]
|
|
bytes_written = os.write(self.stdin.fileno(), chunk)
|
|
self._input_offset += bytes_written
|
|
if self._input_offset >= len(self._input):
|
|
self.stdin.close()
|
|
self._write_set.remove(self.stdin)
|
|
|
|
if self.stdout in rlist:
|
|
data = os.read(self.stdout.fileno(), 1024)
|
|
if not data:
|
|
self.stdout.close()
|
|
self._read_set.remove(self.stdout)
|
|
stdout.append(data)
|
|
|
|
if self.stderr in rlist:
|
|
data = os.read(self.stderr.fileno(), 1024)
|
|
if not data:
|
|
self.stderr.close()
|
|
self._read_set.remove(self.stderr)
|
|
stderr.append(data)
|
|
|
|
return (stdout, stderr)
|
|
|
|
|
|
def send_signal(self, sig):
|
|
"""Send a signal to the process
|
|
"""
|
|
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)
|
|
|
|
|
|
def _demo_posix():
|
|
#
|
|
# Example 1: Simple redirection: Get process list
|
|
#
|
|
plist = Popen(["ps"], stdout=PIPE).communicate()[0]
|
|
print("Process list:")
|
|
print(plist)
|
|
|
|
#
|
|
# Example 2: Change uid before executing child
|
|
#
|
|
if os.getuid() == 0:
|
|
p = Popen(["id"], preexec_fn=lambda: os.setuid(100))
|
|
p.wait()
|
|
|
|
#
|
|
# Example 3: Connecting several subprocesses
|
|
#
|
|
print("Looking for 'hda'...")
|
|
p1 = Popen(["dmesg"], stdout=PIPE)
|
|
p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
|
|
print(repr(p2.communicate()[0]))
|
|
|
|
#
|
|
# Example 4: Catch execution error
|
|
#
|
|
print()
|
|
print("Trying a weird file...")
|
|
try:
|
|
print(Popen(["/this/path/does/not/exist"]).communicate())
|
|
except OSError as e:
|
|
if e.errno == errno.ENOENT:
|
|
print("The file didn't exist. I thought so...")
|
|
print("Child traceback:")
|
|
print(e.child_traceback)
|
|
else:
|
|
print("Error", e.errno)
|
|
else:
|
|
print("Gosh. No error.", file=sys.stderr)
|
|
|
|
|
|
def _demo_windows():
|
|
#
|
|
# Example 1: Connecting several subprocesses
|
|
#
|
|
print("Looking for 'PROMPT' in set output...")
|
|
p1 = Popen("set", stdout=PIPE, shell=True)
|
|
p2 = Popen('find "PROMPT"', stdin=p1.stdout, stdout=PIPE)
|
|
print(repr(p2.communicate()[0]))
|
|
|
|
#
|
|
# Example 2: Simple execution of program
|
|
#
|
|
print("Executing calc...")
|
|
p = Popen("calc")
|
|
p.wait()
|
|
|
|
|
|
if __name__ == "__main__":
|
|
if mswindows:
|
|
_demo_windows()
|
|
else:
|
|
_demo_posix()
|