"""This is like :mod:`pexpect`, but it will work with any socket that you
pass it. You are responsible for opening and closing the socket.
PEXPECT LICENSE
This license is approved by the OSI and FSF as GPL-compatible.
http://opensource.org/licenses/isc-license.txt
Copyright (c) 2012, Noah Spurrier <noah@noah.org>
PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY
PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE
COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES.
THE SOFTWARE IS PROVIDED "AS IS" AND 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, DIRECT, 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.
"""
import socket
from contextlib import contextmanager
from .exceptions import TIMEOUT, EOF
from .spawnbase import SpawnBase
__all__ = ["SocketSpawn"]
[docs]class SocketSpawn(SpawnBase):
"""This is like :mod:`pexpect.fdpexpect` but uses the cross-platform python socket api,
rather than the unix-specific file descriptor api. Thus, it works with
remote connections on both unix and windows."""
[docs] def __init__(
self,
socket: socket.socket,
args=None,
timeout=30,
maxread=2000,
searchwindowsize=None,
logfile=None,
encoding=None,
codec_errors="strict",
use_poll=False,
):
"""This takes an open socket."""
self.args = None
self.command = None
SpawnBase.__init__(
self,
timeout,
maxread,
searchwindowsize,
logfile,
encoding=encoding,
codec_errors=codec_errors,
)
self.socket = socket
self.child_fd = socket.fileno()
self.closed = False
self.name = "<socket %s>" % socket
self.use_poll = use_poll
[docs] def close(self):
"""Close the socket.
Calling this method a second time does nothing, but if the file
descriptor was closed elsewhere, :class:`OSError` will be raised.
"""
if self.child_fd == -1:
return
self.flush()
self.socket.shutdown(socket.SHUT_RDWR)
self.socket.close()
self.child_fd = -1
self.closed = True
[docs] def isalive(self):
""" Alive if the fileno is valid """
return self.socket.fileno() >= 0
def send(self, s) -> int:
"""Write to socket, return number of bytes written"""
s = self._coerce_send_string(s)
self._log(s, "send")
b = self._encoder.encode(s, final=False)
self.socket.sendall(b)
return len(b)
def sendline(self, s) -> int:
"""Write to socket with trailing newline, return number of bytes written"""
s = self._coerce_send_string(s)
return self.send(s + self.linesep)
def write(self, s):
"""Write to socket, return None"""
self.send(s)
def writelines(self, sequence):
"Call self.write() for each item in sequence"
for s in sequence:
self.write(s)
@contextmanager
def _timeout(self, timeout):
saved_timeout = self.socket.gettimeout()
try:
self.socket.settimeout(timeout)
yield
finally:
self.socket.settimeout(saved_timeout)
def read_nonblocking(self, size=1, timeout=-1):
"""
Read from the file descriptor and return the result as a string.
The read_nonblocking method of :class:`SpawnBase` assumes that a call
to os.read will not block (timeout parameter is ignored). This is not
the case for POSIX file-like objects such as sockets and serial ports.
Use :func:`select.select`, timeout is implemented conditionally for
POSIX systems.
:param int size: Read at most *size* bytes.
:param int timeout: Wait timeout seconds for file descriptor to be
ready to read. When -1 (default), use self.timeout. When 0, poll.
:return: String containing the bytes read
"""
if timeout == -1:
timeout = self.timeout
try:
with self._timeout(timeout):
s = self.socket.recv(size)
if s == b'':
self.flag_eof = True
raise EOF("Socket closed")
return s
except socket.timeout:
raise TIMEOUT("Timeout exceeded.")