Start implementing a Pexpect spawn class based on Popen

Initial implementation copied from https://gist.github.com/blink1073/9a0ea82efc84cb9216d0

1 files changed, 83 insertions, 0 deletions

diff --git a/pexpect/popen_spawn.py b/pexpect/popen_spawn.py
new file mode 100644
index 0000000..b3b02bd
--- /dev/null
+++ b/pexpect/popen_spawn.py
@@ -0,0 +1,83 @@
+"""Spawn interface using subprocess.Popen
+"""
+import os
+import threading
+import subprocess
+import sys
+
+try:
+    from queue import Queue  # Python 3
+except ImportError:
+    from Queue import Queue  # Python 2
+
+from .spawnbase import SpawnBase
+
+class PopenSpawn(SpawnBase):
+    def __init__(self, cmd, timeout=30, maxread=2000, searchwindowsize=None,
+                 logfile=None, **kwargs):
+        super(PopenSpawn, self).__init__(timeout=timeout, maxread=maxread,
+                searchwindowsize=searchwindowsize, logfile=logfile)
+                
+        kwargs.update(dict(bufsize=0, stdin=subprocess.PIPE,
+                           stderr=subprocess.STDOUT,
+                           stdout=subprocess.PIPE))
+
+        if sys.platform == 'win32':
+            startupinfo = subprocess.STARTUPINFO()
+            startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
+            kwargs['startupinfo'] = startupinfo
+            kwargs['creationflags'] = subprocess.CREATE_NEW_PROCESS_GROUP
+
+        self.proc = subprocess.Popen(cmd, **kwargs)
+        self._buf = ''
+
+        self._read_queue = Queue()
+        self._read_thread = threading.Thread(target=self._read_incoming)
+        self._read_thread.setDaemon(True)
+        self._read_thread.start()
+
+    def read_nonblocking(self, n):
+        orig = len(self._buf)
+        while 1:
+            try:
+                self._buf += self._read_queue.get_nowait()
+            except Queue.Empty:
+                return
+            else:
+                if len(self._buf) - orig >= n:
+                    return
+
+    def _read_incoming(self):
+        """Run in a thread to move output from a pipe to a queue."""
+        while 1:
+            buf = os.read(self.proc.stdout.fileno(), 1024)
+            self._read_queue.put(buf)
+
+    def readline(self):
+        while not '\n' in self._buf:
+            self.read_nonblocking(1024)
+            ind = self._buf.index('\n')
+            ret, self._buf = self._buf[:ind], self._buf[ind:]
+            return ret
+
+    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):
+        self._log(s, 'send')
+        return self.proc.stdin.write(s)
+
+    def sendline(self, line):
+        return self.send(line + '\n')