Python os.dup2方法代码示例

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def discard_stderr():
    """
    Discards error output of a routine if invoked as:

    with discard_stderr():
        ...
    """
    with open(os.devnull, 'w') as bit_bucket:
        try:
            stderr_fileno = sys.stderr.fileno()
            old_stderr = os.dup(stderr_fileno)
            try:
                os.dup2(bit_bucket.fileno(), stderr_fileno)
                yield
            finally:
                os.dup2(old_stderr, stderr_fileno)
        except AttributeError:
            # On some systems is stderr not a file descriptor but actually a virtual pipeline
            # that can not be copied
            yield 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def daemonize(logfile = None):
    # Fork once
    if os.fork() != 0:
        os._exit(0)
    # Create new session
    os.setsid()
    if os.fork() != 0:
        os._exit(0)
    os.chdir('/')
    fd = os.open('/dev/null', os.O_RDWR)
    os.dup2(fd, sys.__stdin__.fileno())
    if logfile != None:
        fake_stdout = open(logfile, 'a', 1)
        sys.stdout = fake_stdout
        sys.stderr = fake_stdout
        fd = fake_stdout.fileno()
    os.dup2(fd, sys.__stdout__.fileno())
    os.dup2(fd, sys.__stderr__.fileno())
    if logfile == None:
        os.close(fd) 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def start(self):
        try:
            os.fstat(self._savefd)
        except OSError:
            raise ValueError("saved filedescriptor not valid, "
                "did you call start() twice?")
        if self.targetfd == 0 and not self.tmpfile:
            fd = os.open(devnullpath, os.O_RDONLY)
            os.dup2(fd, 0)
            os.close(fd)
            if hasattr(self, '_oldsys'):
                setattr(sys, patchsysdict[self.targetfd], DontReadFromInput())
        else:
            os.dup2(self.tmpfile.fileno(), self.targetfd)
            if hasattr(self, '_oldsys'):
                setattr(sys, patchsysdict[self.targetfd], self.tmpfile) 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def reopen_files(self):
        if self.cfg.capture_output and self.cfg.errorlog != "-":
            for stream in sys.stdout, sys.stderr:
                stream.flush()

            with self.lock:
                if self.logfile is not None:
                    self.logfile.close()
                self.logfile = open(self.cfg.errorlog, 'a+')
                os.dup2(self.logfile.fileno(), sys.stdout.fileno())
                os.dup2(self.logfile.fileno(), sys.stderr.fileno())


        for log in loggers():
            for handler in log.handlers:
                if isinstance(handler, logging.FileHandler):
                    handler.acquire()
                    try:
                        if handler.stream:
                            handler.stream.close()
                            handler.stream = open(handler.baseFilename,
                                    handler.mode)
                    finally:
                        handler.release() 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def stdchannel_redirected(stdchannel, dest_filename):
    """
    A context manager to temporarily redirect stdout or stderr

    e.g.:

    with stdchannel_redirected(sys.stderr, os.devnull):
        if compiler.has_function('clock_gettime', libraries=['rt']):
            libraries.append('rt')
    """

    try:
        oldstdchannel = os.dup(stdchannel.fileno())
        dest_file = open(dest_filename, 'w')
        os.dup2(dest_file.fileno(), stdchannel.fileno())
        yield
    finally:
        if oldstdchannel is not None:
            os.dup2(oldstdchannel, stdchannel.fileno())
        if dest_file is not None:
            dest_file.close() 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def __exit__(self, exc_type, exc_value, traceback):
    os.dup2(self.prevfd, self.fd)


################################################################################
# LOG_MEMORY_PARSING
################################################################################
# Until https://github.com/tensorflow/tensorflow/issues/6716 is resolved, the
# reliable way to get access to tensor deallocation information is to parse
# __LOG_MEMORY__ from VLOG print statements. This is sensitive to print order
# run unbuffered to prevent interleaving:
#   python -u script.py

# Regex'es to parse __LOG_MEMORY__ statements
# Each regex is preceded by an example of line it's meant to pass

# I 5143420588.000000 file tensorflow/core/framework/log_memory.cc:41] __LOG_MEMORY__ MemoryLogTensorAllocation { step_id: -6 kernel_name: "Unknown (from Proto)" tensor { dtype: DT_INT32 shape { dim { size: 3 } } allocation_description { requested_bytes: 12 allocated_bytes: 12 allocator_name: "cpu" allocation_id: 3 has_single_reference: true ptr: 29496256 } } } 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def __init__(self, cmd, bufsize=-1):
        _cleanup()
        self.cmd = cmd
        p2cread, p2cwrite = os.pipe()
        c2pread, c2pwrite = os.pipe()
        self.pid = os.fork()
        if self.pid == 0:
            # Child
            os.dup2(p2cread, 0)
            os.dup2(c2pwrite, 1)
            os.dup2(c2pwrite, 2)
            self._run_child(cmd)
        os.close(p2cread)
        self.tochild = os.fdopen(p2cwrite, 'w', bufsize)
        os.close(c2pwrite)
        self.fromchild = os.fdopen(c2pread, 'r', bufsize) 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def test_large_fd_transfer(self):
        # With fd > 256 (issue #11657)
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"bar", True))
        p.daemon = True
        p.start()
        self.addCleanup(support.unlink, support.TESTFN)
        with open(support.TESTFN, "wb") as f:
            fd = f.fileno()
            for newfd in range(256, MAXFD):
                if not self._is_fd_assigned(newfd):
                    break
            else:
                self.fail("could not find an unassigned large file descriptor")
            os.dup2(fd, newfd)
            try:
                reduction.send_handle(conn, newfd, p.pid)
            finally:
                os.close(newfd)
        p.join()
        with open(support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"bar") 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def redirect_io(log_file='/dev/null'):
    # Always redirect stdin.
    in_fd = os.open('/dev/null', os.O_RDONLY)
    try:
        os.dup2(in_fd, 0)
    finally:
        os.close(in_fd)

    out_fd = os.open(log_file, os.O_WRONLY | os.O_CREAT)
    try:
        os.dup2(out_fd, 2)
        os.dup2(out_fd, 1)
    finally:
        os.close(out_fd)

    sys.stdin = os.fdopen(0, 'r')
    sys.stdout = os.fdopen(1, 'w')
    sys.stderr = os.fdopen(2, 'w') 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def __init__(self, args, close_stderr=False):
    pid, fd = pty.fork()
    if pid == 0:
      # We're the child. Transfer control to command.
      if close_stderr:
        dev_null = os.open('/dev/null', 0)
        os.dup2(dev_null, 2)
      os.execvp(args[0], args)
    else:
      # Disable echoing.
      attr = termios.tcgetattr(fd)
      attr[3] = attr[3] & ~termios.ECHO
      termios.tcsetattr(fd, termios.TCSANOW, attr)
      # Set up a file()-like interface to the child process
      self.r = os.fdopen(fd, 'r', 1)
      self.w = os.fdopen(os.dup(fd), 'w', 1) 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def test_large_fd_transfer(self):
        # With fd > 256 (issue #11657)
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"bar", True))
        p.daemon = True
        p.start()
        with open(test_support.TESTFN, "wb") as f:
            fd = f.fileno()
            for newfd in range(256, MAXFD):
                if not self._is_fd_assigned(newfd):
                    break
            else:
                self.fail("could not find an unassigned large file descriptor")
            os.dup2(fd, newfd)
            try:
                reduction.send_handle(conn, newfd, p.pid)
            finally:
                os.close(newfd)
        p.join()
        with open(test_support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"bar") 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def reopen(logfile):
    print('Signal %d received, reopening logs' % signum)
    if logfile == None:
        return
    fake_stdout = open(logfile, 'a', 1)
    sys.stdout = fake_stdout
    sys.stderr = fake_stdout
    fd = fake_stdout.fileno()
    os.dup2(fd, sys.__stdout__.fileno())
    os.dup2(fd, sys.__stderr__.fileno()) 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def __enter__(self):
        sys.stdout.flush()
        self._contents = None
        self.old_stdout_fileno = sys.stdout.fileno()
        self.bak_stdout_fd = os.dup(self.old_stdout_fileno)
        self.ftmp = tempfile.NamedTemporaryFile(dir=param.TMPDIR)
        os.dup2(self.ftmp.file.fileno(), self.old_stdout_fileno)
        return self 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def __exit__(self, type, value, traceback):
        sys.stdout.flush()
        self.ftmp.file.seek(0)
        self._contents = self.ftmp.file.read()
        self.ftmp.close()
        os.dup2(self.bak_stdout_fd, self.old_stdout_fileno)
        os.close(self.bak_stdout_fd) 

# 需要导入模块: import os [as 别名]
# 或者: from os import dup2 [as 别名]
def done(self):
        """ unpatch and clean up, returns the self.tmpfile (file object)
        """
        os.dup2(self._savefd, self.targetfd)
        os.close(self._savefd)
        if self.targetfd != 0:
            self.tmpfile.seek(0)
        if hasattr(self, '_oldsys'):
            setattr(sys, patchsysdict[self.targetfd], self._oldsys)
        return self.tmpfile