diff options
Diffstat (limited to 'lib/pexpect/popen_spawn.py')
-rw-r--r-- | lib/pexpect/popen_spawn.py | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/lib/pexpect/popen_spawn.py b/lib/pexpect/popen_spawn.py new file mode 100644 index 0000000..4bb58cf --- /dev/null +++ b/lib/pexpect/popen_spawn.py @@ -0,0 +1,188 @@ +"""Provides an interface like pexpect.spawn interface using subprocess.Popen +""" +import os +import threading +import subprocess +import sys +import time +import signal +import shlex + +try: + from queue import Queue, Empty # Python 3 +except ImportError: + from Queue import Queue, Empty # Python 2 + +from .spawnbase import SpawnBase, PY3 +from .exceptions import EOF +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.setDaemon(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: + timeout = self.timeout + elif timeout is None: + timeout = 1e6 + + t0 = time.time() + while (time.time() - t0) < timeout and size and len(buf) < size: + try: + incoming = self._read_queue.get_nowait() + except Empty: + break + else: + if incoming is None: + self._read_reached_eof = True + break + + buf += self._decoder.decode(incoming, final=False) + + r, self._buf = buf[:size], buf[size:] + + self._log(r, 'read') + return r + + def _read_incoming(self): + """Run in a thread to move output from a pipe to a queue.""" + fileno = self.proc.stdout.fileno() + while 1: + buf = b'' + try: + buf = os.read(fileno, 1024) + except OSError as e: + self._log(e, 'read') + + if not buf: + # This indicates we have reached EOF + self._read_queue.put(None) + return + + self._read_queue.put(buf) + + def write(self, s): + '''This is similar to send() except that there is no return value. + ''' + self.send(s) + + def writelines(self, sequence): + '''This calls write() for each element in the sequence. + + The sequence can be any iterable object producing strings, typically a + list of strings. This does not add line separators. There is no return + value. + ''' + for s in sequence: + self.send(s) + + def send(self, s): + '''Send data to the subprocess' stdin. + + Returns the number of bytes written. + ''' + s = self._coerce_send_string(s) + self._log(s, 'send') + + b = self._encoder.encode(s, final=False) + if PY3: + return self.proc.stdin.write(b) + else: + # On Python 2, .write() returns None, so we return the length of + # bytes written ourselves. This assumes they all got written. + self.proc.stdin.write(b) + return len(b) + + def sendline(self, s=''): + '''Wraps send(), sending string ``s`` to child process, with os.linesep + automatically appended. Returns number of bytes written. ''' + + n = self.send(s) + return n + self.send(self.linesep) + + def wait(self): + '''Wait for the subprocess to finish. + + Returns the exit code. + ''' + status = self.proc.wait() + if status >= 0: + self.exitstatus = status + self.signalstatus = None + else: + self.exitstatus = None + self.signalstatus = -status + self.terminated = True + return status + + def kill(self, sig): + '''Sends a Unix signal to the subprocess. + + Use constants from the :mod:`signal` module to specify which signal. + ''' + if sys.platform == 'win32': + if sig in [signal.SIGINT, signal.CTRL_C_EVENT]: + sig = signal.CTRL_C_EVENT + elif sig in [signal.SIGBREAK, signal.CTRL_BREAK_EVENT]: + sig = signal.CTRL_BREAK_EVENT + else: + sig = signal.SIGTERM + + os.kill(self.proc.pid, sig) + + def sendeof(self): + '''Closes the stdin pipe from the writing end.''' + self.proc.stdin.close() |