python编写的一个通过多线程扫描端口的代码详解编程语言

#!/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 , p_end, 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()