PopenSocket

This module for python3 creates socket-like object for communication with child process on Windows using WinAPI.

Anonymous pipes don't have async API, so module uses named pipes to read child's stdout.

Installation

Copy dll from release dir to working dir, or to libs dir (<python.exe dir>/Lib)

Peculiarity:

• Timeout is used only for reading, writting is always synchronous.

• This object should be able to be used in select()

• Recieve only from stdout

  stderr redirected to stderr parent process

Example of useage:

from PopenSocket import PopenSocket
from socket import timeout # import from socket exception (used for compability)

sock = PopenSocket("C:\Windows\System32\cmd.exe", "/c echo 1&ping -n 10 127.0.0.1 > null&echo 2") # ping for sleep
sock.settimeout(1) # 1 second timeout
while True:
  try:
    print(sock.recv(1024))
  except timeout:
    print("timeout")
  except ConnectionAbortedError:
    print("END")
    break

Expected output:

b'1\r\n'
timeout
timeout
timeout
timeout
timeout
timeout
timeout
timeout
timeout
b'2\r\n'
b''
END

API

Constructor

PopenSocket(pathToExecutable, args)

Methods

settimeout(seconds)

recv(sizeToRead) Warning Readed message may be smaller than sizeToRead, like in standart socket.

send(bytesToWrite)

close() - Kills child process

Exceptions

socket.timeout - timeout

ConnectionAbortedError - child close stdout or child done

Build

VS Studio compiler is required for build

python.exe .\setup.py build

Result will be available in build\libs

Conclusion

My personal advice

While I was researching this topic I found a forum post from 2005. In that post senior C developer described a problem of absence Async API for anonymous pipe in windows api. This problem has not been solved until now.

My advice: Use Linux instead of Windows. In Linux this functionallity was supported "from the box"