python编写的一个通过多线程扫描端口的代码

#!/usr/bin/env python
import socket
import sys
import threading
import time
 
NORMAL = 0
ERROR = 1
TIMEOUT = 5
 
def ping(ip,port,timeout=TIMEOUT):
    try:
        cs=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
        cs.settimeout(float(timeout))
        address=(str(ip),int(port))
        status = cs.connect_ex((address))
        if status == NORMAL :
            print "%d is NORMAL" %port
    except Exception,e:
        print ERROR
        print "error:%s" %e
        return ERROR
    cs.close()
    return NORMAL
 
  
class Scan(threading.Thread):
    def __init__(self,ip,timeout):
        threading.Thread.__init__(self)
    self.ip = ip
    self.timeout = timeout
 
    def run(self):
        global p_begin,p_end,mutex
        threadname = threading.currentThread().getName()
        while 1:
            mutex.acquire()
            p_begin += 1
            if p_begin >  p_end:
            mutex.release()
            break
            mutex.release()
        ping(self.ip,p_begin,self.timeout)
 
     
  
if __name__ == '__main__':
    if len(sys.argv) < 4:
    print 'format:urlbegin portbegin portend timeout'
 
    urlbegin = str(sys.argv[1])
    portbegin = int(sys.argv[2])
    portend = int(sys.argv[3])
    timeout = float(sys.argv[4])
 
    global p_begin,mutex
    threads = []
    num = 10
    p_begin = portbegin
    p_end = portend
    mutex = threading.Lock()
    for x in xrange(0,num):
        t_scan = Scan(urlbegin,timeout)
    t_scan.setDaemon(True)
        threads.append(t_scan)
    for t in threads:
        t.start()
    for t in threads:
        t.join()