Class PopenSpawn

pexpect/popen_spawn.py:20–188

from .utils import string_types

class PopenSpawn(SpawnBase):
    def __init__(self, cmd, timeout=30, maxread=2000, searchwindowsize=None,
                 logfile=None, cwd=None, env=None, encoding=None,
                 codec_errors='strict', preexec_fn=None):
        super(PopenSpawn, self).__init__(timeout=timeout, maxread=maxread,
                searchwindowsize=searchwindowsize, logfile=logfile,
                encoding=encoding, codec_errors=codec_errors)

        # Note that `SpawnBase` initializes `self.crlf` to `\r\n`
        # because the default behaviour for a PTY is to convert
        # incoming LF to `\r\n` (see the `onlcr` flag and
        # https://stackoverflow.com/a/35887657/5397009). Here we set
        # it to `os.linesep` because that is what the spawned
        # application outputs by default and `popen` doesn't translate
        # anything.
        if encoding is None:
            self.crlf = os.linesep.encode ("ascii")
        else:
            self.crlf = self.string_type (os.linesep)

        kwargs = dict(bufsize=0, stdin=subprocess.PIPE,
                      stderr=subprocess.STDOUT, stdout=subprocess.PIPE,
                      cwd=cwd, preexec_fn=preexec_fn, env=env)

        if sys.platform == 'win32':
            startupinfo = subprocess.STARTUPINFO()
            startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
            kwargs['startupinfo'] = startupinfo
            kwargs['creationflags'] = subprocess.CREATE_NEW_PROCESS_GROUP

        if isinstance(cmd, string_types) and sys.platform != 'win32':
            cmd = shlex.split(cmd, posix=os.name == 'posix')

        self.proc = subprocess.Popen(cmd, **kwargs)
        self.pid = self.proc.pid
        self.closed = False
        self._buf = self.string_type()

        self._read_queue = Queue()
        self._read_thread = threading.Thread(target=self._read_incoming)
        self._read_thread.daemon = True
        self._read_thread.start()

    _read_reached_eof = False

    def read_nonblocking(self, size, timeout):
        buf = self._buf
        if self._read_reached_eof:
            # We have already finished reading. Use up any buffered data,
            # then raise EOF
            if buf:
                self._buf = buf[size:]
                return buf[:size]
            else:
                self.flag_eof = True
                raise EOF('End Of File (EOF).')

        if timeout == -1: