+# subprocess - Subprocesses with accessible I/O streams
+#
+# For more information about this module, see PEP 324.
+#
+# Copyright (c) 2003-2004 by Peter Astrand <astrand@lysator.liu.se>
+#
+# By obtaining, using, and/or copying this software and/or its
+# associated documentation, you agree that you have read, understood,
+# and will comply with the following terms and conditions:
+#
+# Permission to use, copy, modify, and distribute this software and
+# its associated documentation for any purpose and without fee is
+# hereby granted, provided that the above copyright notice appears in
+# all copies, and that both that copyright notice and this permission
+# notice appear in supporting documentation, and that the name of the
+# author not be used in advertising or publicity pertaining to
+# distribution of the software without specific, written prior
+# permission.
+#
+# THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+# INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
+# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
+# WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""subprocess - Subprocesses with accessible I/O streams
+
+This module allows you to spawn processes and connect to their
+input/output/error pipes and obtain their return codes under Unix.
+This module intends to replace several other, older modules and
+functions, like:
+
+os.system
+os.spawn*
+os.popen*
+popen2.*
+commands.*
+
+Information about how the subprocess module can be used to replace these
+modules and functions can be found below.
+
+
+
+Using the subprocess module
+===========================
+This module defines one class called Popen:
+
+class Popen(args, bufsize=0, executable=None,
+ stdin=None, stdout=None, stderr=None,
+ preexec_fn=None, close_fds=False, shell=False,
+ cwd=None, env=None, universal_newlines=False,
+ startupinfo=None, creationflags=0):
+
+
+Arguments are:
+
+args should be a string, or a sequence of program arguments. The
+program to execute is normally the first item in the args sequence or
+string, but can be explicitly set by using the executable argument.
+
+On UNIX, with shell=False (default): In this case, the Popen class
+uses os.execvp() to execute the child program. args should normally
+be a sequence. A string will be treated as a sequence with the string
+as the only item (the program to execute).
+
+On UNIX, with shell=True: If args is a string, it specifies the
+command string to execute through the shell. If args is a sequence,
+the first item specifies the command string, and any additional items
+will be treated as additional shell arguments.
+
+On Windows: the Popen class uses CreateProcess() to execute the child
+program, which operates on strings. If args is a sequence, it will be
+converted to a string using the list2cmdline method. Please note that
+not all MS Windows applications interpret the command line the same
+way: The list2cmdline is designed for applications using the same
+rules as the MS C runtime.
+
+bufsize, if given, has the same meaning as the corresponding argument
+to the built-in open() function: 0 means unbuffered, 1 means line
+buffered, any other positive value means use a buffer of
+(approximately) that size. A negative bufsize means to use the system
+default, which usually means fully buffered. The default value for
+bufsize is 0 (unbuffered).
+
+stdin, stdout and stderr specify the executed programs' standard
+input, standard output and standard error file handles, respectively.
+Valid values are PIPE, an existing file descriptor (a positive
+integer), an existing file object, and None. PIPE indicates that a
+new pipe to the child should be created. With None, no redirection
+will occur; the child's file handles will be inherited from the
+parent. Additionally, stderr can be STDOUT, which indicates that the
+stderr data from the applications should be captured into the same
+file handle as for stdout.
+
+If preexec_fn is set to a callable object, this object will be called
+in the child process just before the child is executed.
+
+If close_fds is true, all file descriptors except 0, 1 and 2 will be
+closed before the child process is executed.
+
+if shell is true, the specified command will be executed through the
+shell.
+
+If cwd is not None, the current directory will be changed to cwd
+before the child is executed.
+
+If env is not None, it defines the environment variables for the new
+process.
+
+If universal_newlines is true, the file objects stdout and stderr are
+opened as a text files, but lines may be terminated by any of '\n',
+the Unix end-of-line convention, '\r', the Macintosh convention or
+'\r\n', the Windows convention. All of these external representations
+are seen as '\n' by the Python program. Note: This feature is only
+available if Python is built with universal newline support (the
+default). Also, the newlines attribute of the file objects stdout,
+stdin and stderr are not updated by the communicate() method.
+
+The startupinfo and creationflags, if given, will be passed to the
+underlying CreateProcess() function. They can specify things such as
+appearance of the main window and priority for the new process.
+(Windows only)
+
+
+This module also defines two shortcut functions:
+
+call(*args, **kwargs):
+ Run command with arguments. Wait for command to complete, then
+ return the returncode attribute.
+
+ The arguments are the same as for the Popen constructor. Example:
+
+ retcode = call(["ls", "-l"])
+
+
+Exceptions
+----------
+Exceptions raised in the child process, before the new program has
+started to execute, will be re-raised in the parent. Additionally,
+the exception object will have one extra attribute called
+'child_traceback', which is a string containing traceback information
+from the childs point of view.
+
+The most common exception raised is OSError. This occurs, for
+example, when trying to execute a non-existent file. Applications
+should prepare for OSErrors.
+
+A ValueError will be raised if Popen is called with invalid arguments.
+
+
+Security
+--------
+Unlike some other popen functions, this implementation will never call
+/bin/sh implicitly. This means that all characters, including shell
+metacharacters, can safely be passed to child processes.
+
+
+Popen objects
+=============
+Instances of the Popen class have the following methods:
+
+poll()
+ Check if child process has terminated. Returns returncode
+ attribute.
+
+wait()
+ Wait for child process to terminate. Returns returncode attribute.
+
+communicate(input=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 stdin 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).
+
+ Note: The data read is buffered in memory, so do not use this
+ method if the data size is large or unlimited.
+
+The following attributes are also available:
+
+stdin
+ If the stdin argument is PIPE, this attribute is a file object
+ that provides input to the child process. Otherwise, it is None.
+
+stdout
+ If the stdout argument is PIPE, this attribute is a file object
+ that provides output from the child process. Otherwise, it is
+ None.
+
+stderr
+ If the stderr argument is PIPE, this attribute is file object that
+ provides error output from the child process. Otherwise, it is
+ None.
+
+pid
+ The process ID of the child process.
+
+returncode
+ The child return code. A None value indicates that the process
+ hasn't terminated yet. A negative value -N indicates that the
+ child was terminated by signal N (UNIX only).
+
+
+Replacing older functions with the subprocess module
+====================================================
+In this section, "a ==> b" means that b can be used as a replacement
+for a.
+
+Note: All functions in this section fail (more or less) silently if
+the executed program cannot be found; this module raises an OSError
+exception.
+
+In the following examples, we assume that the subprocess module is
+imported with "from subprocess import *".
+
+
+Replacing /bin/sh shell backquote
+---------------------------------
+output=`mycmd myarg`
+==>
+output = Popen(["mycmd", "myarg"], stdout=PIPE).communicate()[0]
+
+
+Replacing shell pipe line
+-------------------------
+output=`dmesg | grep hda`
+==>
+p1 = Popen(["dmesg"], stdout=PIPE)
+p2 = Popen(["grep", "hda"], stdin=p1.stdout)
+output = p2.communicate()[0]
+
+
+Replacing os.system()
+---------------------
+sts = os.system("mycmd" + " myarg")
+==>
+p = Popen("mycmd" + " myarg", shell=True)
+sts = os.waitpid(p.pid, 0)
+
+Note:
+
+* Calling the program through the shell is usually not required.
+
+* It's easier to look at the returncode attribute than the
+ exitstatus.
+
+A more real-world example would look like this:
+
+try:
+ retcode = call("mycmd" + " myarg", shell=True)
+ if retcode < 0:
+ print >>sys.stderr, "Child was terminated by signal", -retcode
+ else:
+ print >>sys.stderr, "Child returned", retcode
+except OSError, e:
+ print >>sys.stderr, "Execution failed:", e
+
+
+Replacing os.spawn*
+-------------------
+P_NOWAIT example:
+
+pid = os.spawnlp(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg")
+==>
+pid = Popen(["/bin/mycmd", "myarg"]).pid
+
+
+P_WAIT example:
+
+retcode = os.spawnlp(os.P_WAIT, "/bin/mycmd", "mycmd", "myarg")
+==>
+retcode = call(["/bin/mycmd", "myarg"])
+
+
+Vector example:
+
+os.spawnvp(os.P_NOWAIT, path, args)
+==>
+Popen([path] + args[1:])
+
+
+Environment example:
+
+os.spawnlpe(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg", env)
+==>
+Popen(["/bin/mycmd", "myarg"], env={"PATH": "/usr/bin"})
+
+
+Replacing os.popen*
+-------------------
+pipe = os.popen(cmd, mode='r', bufsize)
+==>
+pipe = Popen(cmd, shell=True, bufsize=bufsize, stdout=PIPE).stdout
+
+pipe = os.popen(cmd, mode='w', bufsize)
+==>
+pipe = Popen(cmd, shell=True, bufsize=bufsize, stdin=PIPE).stdin
+
+
+(child_stdin, child_stdout) = os.popen2(cmd, mode, bufsize)
+==>
+p = Popen(cmd, shell=True, bufsize=bufsize,
+ stdin=PIPE, stdout=PIPE, close_fds=True)
+(child_stdin, child_stdout) = (p.stdin, p.stdout)
+
+
+(child_stdin,
+ child_stdout,
+ child_stderr) = os.popen3(cmd, mode, bufsize)
+==>
+p = Popen(cmd, shell=True, bufsize=bufsize,
+ stdin=PIPE, stdout=PIPE, stderr=PIPE, close_fds=True)
+(child_stdin,
+ child_stdout,
+ child_stderr) = (p.stdin, p.stdout, p.stderr)
+
+
+(child_stdin, child_stdout_and_stderr) = os.popen4(cmd, mode, bufsize)
+==>
+p = Popen(cmd, shell=True, bufsize=bufsize,
+ stdin=PIPE, stdout=PIPE, stderr=STDOUT, close_fds=True)
+(child_stdin, child_stdout_and_stderr) = (p.stdin, p.stdout)
+
+
+Replacing popen2.*
+------------------
+Note: If the cmd argument to popen2 functions is a string, the command
+is executed through /bin/sh. If it is a list, the command is directly
+executed.
+
+(child_stdout, child_stdin) = popen2.popen2("somestring", bufsize, mode)
+==>
+p = Popen(["somestring"], shell=True, bufsize=bufsize
+ stdin=PIPE, stdout=PIPE, close_fds=True)
+(child_stdout, child_stdin) = (p.stdout, p.stdin)
+
+
+(child_stdout, child_stdin) = popen2.popen2(["mycmd", "myarg"], bufsize, mode)
+==>
+p = Popen(["mycmd", "myarg"], bufsize=bufsize,
+ stdin=PIPE, stdout=PIPE, close_fds=True)
+(child_stdout, child_stdin) = (p.stdout, p.stdin)
+
+The popen2.Popen3 and popen3.Popen4 basically works as subprocess.Popen,
+except that:
+
+* subprocess.Popen raises an exception if the execution fails
+* the capturestderr argument is replaced with the stderr argument.
+* stdin=PIPE and stdout=PIPE must be specified.
+* popen2 closes all filedescriptors by default, but you have to specify
+ close_fds=True with subprocess.Popen.
+
+
+"""
+
+import sys
+mswindows = (sys.platform == "win32")
+
+import os
+import types
+import traceback
+
+if mswindows:
+ import threading
+ import msvcrt
+ if 0: # <-- change this to use pywin32 instead of the _subprocess driver
+ import pywintypes
+ from win32api import GetStdHandle, STD_INPUT_HANDLE, \
+ STD_OUTPUT_HANDLE, STD_ERROR_HANDLE
+ from win32api import GetCurrentProcess, DuplicateHandle, \
+ GetModuleFileName, GetVersion
+ from win32con import DUPLICATE_SAME_ACCESS
+ from win32pipe import CreatePipe
+ from win32process import CreateProcess, STARTUPINFO, \
+ GetExitCodeProcess, STARTF_USESTDHANDLES, \
+ CREATE_NEW_CONSOLE
+ from win32event import WaitForSingleObject, INFINITE, WAIT_OBJECT_0
+ else:
+ from _subprocess import *
+ class STARTUPINFO:
+ dwFlags = 0
+ hStdInput = None
+ hStdOutput = None
+ hStdError = None
+ class pywintypes:
+ error = IOError
+else:
+ import select
+ import errno
+ import fcntl
+ import pickle
+
+__all__ = ["Popen", "PIPE", "STDOUT", "call"]
+
+try:
+ MAXFD = os.sysconf("SC_OPEN_MAX")
+except:
+ MAXFD = 256
+
+# True/False does not exist on 2.2.0
+try:
+ False
+except NameError:
+ False = 0
+ True = 1
+
+_active = []
+
+def _cleanup():
+ for inst in _active[:]:
+ inst.poll()
+
+PIPE = -1
+STDOUT = -2
+
+
+def call(*args, **kwargs):
+ """Run command with arguments. Wait for command to complete, then
+ return the returncode attribute.
+
+ The arguments are the same as for the Popen constructor. Example:
+
+ retcode = call(["ls", "-l"])
+ """
+ return Popen(*args, **kwargs).wait()
+
+
+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/library/en-us/vccelng/htm/progs_12.asp
+ 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)
+ 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 backspaces.
+ 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 backspaces, if any.
+ if bs_buf:
+ result.extend(bs_buf)
+
+ if needquote:
+ result.append('"')
+
+ return ''.join(result)
+
+
+class Popen(object):
+ def __init__(self, args, bufsize=0, executable=None,
+ stdin=None, stdout=None, stderr=None,
+ preexec_fn=None, close_fds=False, shell=False,
+ cwd=None, env=None, universal_newlines=False,
+ startupinfo=None, creationflags=0):
+ """Create new Popen instance."""
+ _cleanup()
+
+ if mswindows:
+ if preexec_fn is not None:
+ raise ValueError("preexec_fn is not supported on Windows "
+ "platforms")
+ if close_fds:
+ raise ValueError("close_fds is not supported on Windows "
+ "platforms")
+ else:
+ # POSIX
+ 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.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 None when not using PIPEs. The child objects are None
+ # when not redirecting.
+
+ (p2cread, p2cwrite,
+ c2pread, c2pwrite,
+ errread, errwrite) = self._get_handles(stdin, stdout, stderr)
+
+ self._execute_child(args, executable, preexec_fn, close_fds,
+ cwd, env, universal_newlines,
+ startupinfo, creationflags, shell,
+ p2cread, p2cwrite,
+ c2pread, c2pwrite,
+ errread, errwrite)
+
+ if p2cwrite:
+ self.stdin = os.fdopen(p2cwrite, 'wb', bufsize)
+ if c2pread:
+ if universal_newlines:
+ self.stdout = os.fdopen(c2pread, 'rU', bufsize)
+ else:
+ self.stdout = os.fdopen(c2pread, 'rb', bufsize)
+ if errread:
+ if universal_newlines:
+ self.stderr = os.fdopen(errread, 'rU', bufsize)
+ else:
+ self.stderr = os.fdopen(errread, 'rb', bufsize)
+
+ _active.append(self)
+
+
+ def _translate_newlines(self, data):
+ data = data.replace("\r\n", "\n")
+ data = data.replace("\r", "\n")
+ return data
+
+
+ if mswindows:
+ #
+ # Windows methods
+ #
+ def _get_handles(self, stdin, stdout, stderr):
+ """Construct and return tupel with IO objects:
+ p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite
+ """
+ if stdin == None and stdout == None and stderr == None:
+ return (None, None, None, None, None, None)
+
+ p2cread, p2cwrite = None, None
+ c2pread, c2pwrite = None, None
+ errread, errwrite = None, None
+
+ if stdin == None:
+ p2cread = GetStdHandle(STD_INPUT_HANDLE)
+ elif stdin == PIPE:
+ p2cread, p2cwrite = CreatePipe(None, 0)
+ # Detach and turn into fd
+ p2cwrite = p2cwrite.Detach()
+ p2cwrite = msvcrt.open_osfhandle(p2cwrite, 0)
+ elif type(stdin) == types.IntType:
+ p2cread = msvcrt.get_osfhandle(stdin)
+ else:
+ # Assuming file-like object
+ p2cread = msvcrt.get_osfhandle(stdin.fileno())
+ p2cread = self._make_inheritable(p2cread)
+
+ if stdout == None:
+ c2pwrite = GetStdHandle(STD_OUTPUT_HANDLE)
+ elif stdout == PIPE:
+ c2pread, c2pwrite = CreatePipe(None, 0)
+ # Detach and turn into fd
+ c2pread = c2pread.Detach()
+ c2pread = msvcrt.open_osfhandle(c2pread, 0)
+ elif type(stdout) == types.IntType:
+ c2pwrite = msvcrt.get_osfhandle(stdout)
+ else:
+ # Assuming file-like object
+ c2pwrite = msvcrt.get_osfhandle(stdout.fileno())
+ c2pwrite = self._make_inheritable(c2pwrite)
+
+ if stderr == None:
+ errwrite = GetStdHandle(STD_ERROR_HANDLE)
+ elif stderr == PIPE:
+ errread, errwrite = CreatePipe(None, 0)
+ # Detach and turn into fd
+ errread = errread.Detach()
+ errread = msvcrt.open_osfhandle(errread, 0)
+ elif stderr == STDOUT:
+ errwrite = c2pwrite
+ elif type(stderr) == types.IntType:
+ 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 DuplicateHandle(GetCurrentProcess(), handle,
+ GetCurrentProcess(), 0, 1,
+ DUPLICATE_SAME_ACCESS)
+
+
+ def _find_w9xpopen(self):
+ """Find and return absolut path to w9xpopen.exe"""
+ w9xpopen = os.path.join(os.path.dirname(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,
+ cwd, env, universal_newlines,
+ startupinfo, creationflags, shell,
+ p2cread, p2cwrite,
+ c2pread, c2pwrite,
+ errread, errwrite):
+ """Execute program (MS Windows version)"""
+
+ if not isinstance(args, types.StringTypes):
+ args = list2cmdline(args)
+
+ if shell:
+ comspec = os.environ.get("COMSPEC", "cmd.exe")
+ args = comspec + " /c " + args
+ if (GetVersion() >= 0x80000000L 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 wont
+ # kill children.
+ creationflags |= CREATE_NEW_CONSOLE
+
+ # Process startup details
+ if startupinfo == None:
+ startupinfo = STARTUPINFO()
+ if not None in (p2cread, c2pwrite, errwrite):
+ startupinfo.dwFlags |= STARTF_USESTDHANDLES
+ startupinfo.hStdInput = p2cread
+ startupinfo.hStdOutput = c2pwrite
+ startupinfo.hStdError = errwrite
+
+ # Start the process
+ try:
+ hp, ht, pid, tid = CreateProcess(executable, args,
+ # no special security
+ None, None,
+ # must inherit handles to pass std
+ # handles
+ 1,
+ creationflags,
+ env,
+ cwd,
+ startupinfo)
+ except pywintypes.error, 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)
+
+ # Retain the process handle, but close the thread handle
+ self._handle = hp
+ self.pid = pid
+ ht.Close()
+
+ # 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 != None:
+ p2cread.Close()
+ if c2pwrite != None:
+ c2pwrite.Close()
+ if errwrite != None:
+ errwrite.Close()
+
+
+ def poll(self):
+ """Check if child process has terminated. Returns returncode
+ attribute."""
+ if self.returncode == None:
+ if WaitForSingleObject(self._handle, 0) == WAIT_OBJECT_0:
+ self.returncode = GetExitCodeProcess(self._handle)
+ _active.remove(self)
+ return self.returncode
+
+
+ def wait(self):
+ """Wait for child process to terminate. Returns returncode
+ attribute."""
+ if self.returncode == None:
+ obj = WaitForSingleObject(self._handle, INFINITE)
+ self.returncode = GetExitCodeProcess(self._handle)
+ _active.remove(self)
+ return self.returncode
+
+
+ def _readerthread(self, fh, buffer):
+ buffer.append(fh.read())
+
+
+ def communicate(self, input=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)."""
+ stdout = None # Return
+ stderr = None # Return
+
+ if self.stdout:
+ stdout = []
+ stdout_thread = threading.Thread(target=self._readerthread,
+ args=(self.stdout, stdout))
+ stdout_thread.setDaemon(True)
+ stdout_thread.start()
+ if self.stderr:
+ stderr = []
+ stderr_thread = threading.Thread(target=self._readerthread,
+ args=(self.stderr, stderr))
+ stderr_thread.setDaemon(True)
+ stderr_thread.start()
+
+ if self.stdin:
+ if input != None:
+ self.stdin.write(input)
+ self.stdin.close()
+
+ if self.stdout:
+ stdout_thread.join()
+ if self.stderr:
+ stderr_thread.join()
+
+ # All data exchanged. Translate lists into strings.
+ if stdout != None:
+ stdout = stdout[0]
+ if stderr != None:
+ stderr = stderr[0]
+
+ # Translate newlines, if requested. We cannot let the file
+ # object do the translation: It is based on stdio, which is
+ # impossible to combine with select (unless forcing no
+ # buffering).
+ if self.universal_newlines and hasattr(open, 'newlines'):
+ if stdout:
+ stdout = self._translate_newlines(stdout)
+ if stderr:
+ stderr = self._translate_newlines(stderr)
+
+ self.wait()
+ return (stdout, stderr)
+
+ else:
+ #
+ # POSIX methods
+ #
+ def _get_handles(self, stdin, stdout, stderr):
+ """Construct and return tupel with IO objects:
+ p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite
+ """
+ p2cread, p2cwrite = None, None
+ c2pread, c2pwrite = None, None
+ errread, errwrite = None, None
+
+ if stdin == None:
+ pass
+ elif stdin == PIPE:
+ p2cread, p2cwrite = os.pipe()
+ elif type(stdin) == types.IntType:
+ p2cread = stdin
+ else:
+ # Assuming file-like object
+ p2cread = stdin.fileno()
+
+ if stdout == None:
+ pass
+ elif stdout == PIPE:
+ c2pread, c2pwrite = os.pipe()
+ elif type(stdout) == types.IntType:
+ c2pwrite = stdout
+ else:
+ # Assuming file-like object
+ c2pwrite = stdout.fileno()
+
+ if stderr == None:
+ pass
+ elif stderr == PIPE:
+ errread, errwrite = os.pipe()
+ elif stderr == STDOUT:
+ errwrite = c2pwrite
+ elif type(stderr) == types.IntType:
+ errwrite = stderr
+ else:
+ # Assuming file-like object
+ errwrite = stderr.fileno()
+
+ return (p2cread, p2cwrite,
+ c2pread, c2pwrite,
+ errread, errwrite)
+
+
+ def _set_cloexec_flag(self, fd):
+ try:
+ cloexec_flag = fcntl.FD_CLOEXEC
+ except AttributeError:
+ cloexec_flag = 1
+
+ old = fcntl.fcntl(fd, fcntl.F_GETFD)
+ fcntl.fcntl(fd, fcntl.F_SETFD, old | cloexec_flag)
+
+
+ def _close_fds(self, but):
+ for i in range(3, MAXFD):
+ if i == but:
+ continue
+ try:
+ os.close(i)
+ except:
+ pass
+
+
+ def _execute_child(self, args, executable, preexec_fn, close_fds,
+ cwd, env, universal_newlines,
+ startupinfo, creationflags, shell,
+ p2cread, p2cwrite,
+ c2pread, c2pwrite,
+ errread, errwrite):
+ """Execute program (POSIX version)"""
+
+ if isinstance(args, types.StringTypes):
+ args = [args]
+
+ if shell:
+ args = ["/bin/sh", "-c"] + args
+
+ if executable == None:
+ executable = args[0]
+
+ # For transferring possible exec failure from child to parent
+ # The first char specifies the exception type: 0 means
+ # OSError, 1 means some other error.
+ errpipe_read, errpipe_write = os.pipe()
+ self._set_cloexec_flag(errpipe_write)
+
+ self.pid = os.fork()
+ if self.pid == 0:
+ # Child
+ try:
+ # Close parent's pipe ends
+ if p2cwrite:
+ os.close(p2cwrite)
+ if c2pread:
+ os.close(c2pread)
+ if errread:
+ os.close(errread)
+ os.close(errpipe_read)
+
+ # Dup fds for child
+ if p2cread:
+ os.dup2(p2cread, 0)
+ if c2pwrite:
+ os.dup2(c2pwrite, 1)
+ if errwrite:
+ os.dup2(errwrite, 2)
+
+ # Close pipe fds. Make sure we doesn't close the same
+ # fd more than once.
+ if p2cread:
+ os.close(p2cread)
+ if c2pwrite and c2pwrite not in (p2cread,):
+ os.close(c2pwrite)
+ if errwrite and errwrite not in (p2cread, c2pwrite):
+ os.close(errwrite)
+
+ # Close all other fds, if asked for
+ if close_fds:
+ self._close_fds(but=errpipe_write)
+
+ if cwd != None:
+ os.chdir(cwd)
+
+ if preexec_fn:
+ apply(preexec_fn)
+
+ if env == None:
+ os.execvp(executable, args)
+ else:
+ os.execvpe(executable, args, env)
+
+ except:
+ exc_type, exc_value, tb = sys.exc_info()
+ # Save the traceback and attach it to the exception object
+ exc_lines = traceback.format_exception(exc_type,
+ exc_value,
+ tb)
+ exc_value.child_traceback = ''.join(exc_lines)
+ os.write(errpipe_write, pickle.dumps(exc_value))
+
+ # This exitcode won't be reported to applications, so it
+ # really doesn't matter what we return.
+ os._exit(255)
+
+ # Parent
+ os.close(errpipe_write)
+ if p2cread and p2cwrite:
+ os.close(p2cread)
+ if c2pwrite and c2pread:
+ os.close(c2pwrite)
+ if errwrite and errread:
+ os.close(errwrite)
+
+ # Wait for exec to fail or succeed; possibly raising exception
+ data = os.read(errpipe_read, 1048576) # Exceptions limited to 1 MB
+ os.close(errpipe_read)
+ if data != "":
+ child_exception = pickle.loads(data)
+ raise child_exception
+
+
+ def _handle_exitstatus(self, sts):
+ if os.WIFSIGNALED(sts):
+ self.returncode = -os.WTERMSIG(sts)
+ elif os.WIFEXITED(sts):
+ self.returncode = os.WEXITSTATUS(sts)
+ else:
+ # Should never happen
+ raise RuntimeError("Unknown child exit status!")
+
+ _active.remove(self)
+
+
+ def poll(self):
+ """Check if child process has terminated. Returns returncode
+ attribute."""
+ if self.returncode == None:
+ try:
+ pid, sts = os.waitpid(self.pid, os.WNOHANG)
+ if pid == self.pid:
+ self._handle_exitstatus(sts)
+ except os.error:
+ pass
+ return self.returncode
+
+
+ def wait(self):
+ """Wait for child process to terminate. Returns returncode
+ attribute."""
+ if self.returncode == None:
+ pid, sts = os.waitpid(self.pid, 0)
+ self._handle_exitstatus(sts)
+ return self.returncode
+
+
+ def communicate(self, input=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)."""
+ read_set = []
+ write_set = []
+ stdout = None # Return
+ stderr = None # Return
+
+ if self.stdin:
+ # Flush stdio buffer. This might block, if the user has
+ # been writing to .stdin in an uncontrolled fashion.
+ self.stdin.flush()
+ if input:
+ write_set.append(self.stdin)
+ else:
+ self.stdin.close()
+ if self.stdout:
+ read_set.append(self.stdout)
+ stdout = []
+ if self.stderr:
+ read_set.append(self.stderr)
+ stderr = []
+
+ while read_set or write_set:
+ rlist, wlist, xlist = select.select(read_set, write_set, [])
+
+ if self.stdin in wlist:
+ # When select has indicated that the file is writable,
+ # we can write up to PIPE_BUF bytes without risk
+ # blocking. POSIX defines PIPE_BUF >= 512
+ bytes_written = os.write(self.stdin.fileno(), input[:512])
+ input = input[bytes_written:]
+ if not input:
+ self.stdin.close()
+ write_set.remove(self.stdin)
+
+ if self.stdout in rlist:
+ data = os.read(self.stdout.fileno(), 1024)
+ if data == "":
+ self.stdout.close()
+ read_set.remove(self.stdout)
+ stdout.append(data)
+
+ if self.stderr in rlist:
+ data = os.read(self.stderr.fileno(), 1024)
+ if data == "":
+ self.stderr.close()
+ read_set.remove(self.stderr)
+ stderr.append(data)
+
+ # All data exchanged. Translate lists into strings.
+ if stdout != None:
+ stdout = ''.join(stdout)
+ if stderr != None:
+ stderr = ''.join(stderr)
+
+ # Translate newlines, if requested. We cannot let the file
+ # object do the translation: It is based on stdio, which is
+ # impossible to combine with select (unless forcing no
+ # buffering).
+ if self.universal_newlines and hasattr(open, 'newlines'):
+ if stdout:
+ stdout = self._translate_newlines(stdout)
+ if stderr:
+ stderr = self._translate_newlines(stderr)
+
+ self.wait()
+ return (stdout, stderr)
+
+
+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, 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 >>sys.stderr, "Gosh. No error."
+
+
+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()
projects / wxWidgets.git / commitdiff
