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Diffstat (limited to 'compat')
| -rw-r--r-- | compat/subprocess.py | 1149 |
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diff --git a/compat/subprocess.py b/compat/subprocess.py deleted file mode 100644 index 6474eab11..000000000 --- a/compat/subprocess.py +++ /dev/null @@ -1,1149 +0,0 @@ -# subprocess - Subprocesses with accessible I/O streams -# -# For more information about this module, see PEP 324. -# -# This module should remain compatible with Python 2.2, see PEP 291. -# -# Copyright (c) 2003-2005 by Peter Astrand <astrand@lysator.liu.se> -# -# Licensed to PSF under a Contributor Agreement. -# See http://www.python.org/2.4/license for licensing details. - -r"""subprocess - Subprocesses with accessible I/O streams - -This module allows you to spawn processes, connect to their -input/output/error pipes, and obtain their return codes. 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, stdout=PIPE) -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, SW_HIDE - from win32pipe import CreatePipe - from win32process import CreateProcess, STARTUPINFO, \ - GetExitCodeProcess, STARTF_USESTDHANDLES, \ - STARTF_USESHOWWINDOW, 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.extend(bs_buf) - 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 not isinstance(bufsize, (int, long)): - 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") - 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 tuple 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 absolute 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) - - # Process startup details - default_startupinfo = STARTUPINFO() - if startupinfo == None: - startupinfo = default_startupinfo - if not None in (p2cread, c2pwrite, errwrite): - startupinfo.dwFlags |= STARTF_USESTDHANDLES - startupinfo.hStdInput = p2cread - startupinfo.hStdOutput = c2pwrite - startupinfo.hStdError = errwrite - - if shell: - default_startupinfo.dwFlags |= STARTF_USESHOWWINDOW - default_startupinfo.wShowWindow = SW_HIDE - 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 - - # 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 tuple 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 != "": - os.waitpid(self.pid, 0) - 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() |