Using Python to check if remote port is open and accessible.

README.md

Using Python to check if remote port is open and accessible.

Taken from http://snipplr.com/view/19639/test-if-an-ipport-is-open/

Usage:

• Open a Python prompt
• Run the script in is_port_open.py
• Call isOpen with a host and a port parameter. Example: isOpen("www.google.com", 80)

is_port_open.py

import socket
def isOpen(ip,port):
   s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
   try:
      s.connect((ip, int(port)))
      s.shutdown(2)
      return True
   except:
      return False

Small note, this can be sped up by using connect_ex instead of connect. The first call will not raise any exceptions (except for No host found, but that's standard) and is faster than the second one. Example:

Thanks for sharing this Oscar.

An async version:

async def wait_host_port(host, port, duration=10, delay=2):
    """Repeatedly try if a port on a host is open until duration seconds passed
    
    Parameters
    ----------
    host : str
        host ip address or hostname
    port : int
        port number
    duration : int, optional
        Total duration in seconds to wait, by default 10
    delay : int, optional
        delay in seconds between each try, by default 2
    
    Returns
    -------
    awaitable bool
    """
    tmax = time.time() + duration
    while time.time() < tmax:
        try:
            _reader, writer = await asyncio.wait_for(asyncio.open_connection(host, port), timeout=5)
            writer.close()
            await writer.wait_closed()
            return True
        except:
            if delay:
                await asyncio.sleep(delay)
    return False

Thank you for the code. It works, but in python3.6, I get an exception like this 'StreamWriter' object has no attribute 'wait_closed'. Could you tell me how to fix it. Please

the .wait_closed() method was added in python 3.7