import random
import shlex
import socket
import subprocess
[docs]def unused_port(range=None):
if range:
return __unused_port_on_range(range)
else:
return __unused_port_rangeless()
def __unused_port_rangeless():
# TODO: Allow ranges (though then need to guess and check)...
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('localhost', 0))
addr, port = s.getsockname()
s.close()
return port
def __unused_port_on_range(range):
assert range[0] and range[1]
# Find all ports that are already occupied
cmd_netstat = shlex.split("netstat tuln")
p1 = subprocess.Popen(cmd_netstat, stdout=subprocess.PIPE)
occupied_ports = set()
for line in p1.stdout.read().split('\n'):
if line.startswith('tcp') or line.startswith('tcp6'):
col = line.split()
local_address = col[3]
local_port = local_address.split(':')[1]
occupied_ports.add(int(local_port))
# Generate random free port number.
while True:
port = random.randrange(range[0], range[1])
if port not in occupied_ports:
break
return port