[python] port scanner

import optparse
from socket import *
from threading import *

screenLock = Semaphore(value=1)
def connScan(tgtHost, tgtPort):
    try:
        connSkt = socket(AF_INET, SOCK_STREAM)
        connSkt.connect(tgtHost, tgtPort)
        connSkt.send('ViolentPython\r\n')
        results = connSkt.recv(100)
        screenLock.acquire()
        print ('[+] %d/tcp open'% tgtPort)
        print ('[+] '+str(results))
    except:
        screenLock.acquire()
        print ('[-] %d/tcp closed'% tgtPort)
    finally:
        screenLock.acquire()
        connSkt.close()

def portScan(tgtHost, tgtPorts):
    try:
        tgtIP = gethostbyname(tgtHost)
    except:
        print ("[-] Cannet resolve '%s': Unknown host'"% tgtHost)
        return
    try:
        tgtName = gethostbyaddr(tgtIP)
        print ("\n[+] Scan Results for: "+tgtName[0])
    except:
        print ("\n[+] Scan Results for: "+tgtIP)
    setdefaulttimeout(1)
    for tgtPort in tgtPorts:
        t = Thread(target=connScan, args=(tgtHost, int(tgtPort)))
        t.start()
        print ("Scanning Port "+ tgtPort)

def main():
    parser = optparse.OptionParser('usage %prog -H -p ')
    parser.add_option('-H', dest='tgtHost', type='string', help='specify target host')
    parser.add_option('-p', dest='tgtPort', type='string', help='specify target port')
    (options, args) = parser.parse_args()
    tgtHost = options.tgtHost
    tgtPorts = str(options.tgtPort).split(',')
    if (tgtHost == None) | (tgtPorts[0] == None):
        print (parser.usage)
        exit(0)
    portScan(tgtHost, tgtPorts)

if __name__ == '__main__':
    main()

#'print (tgtHost+', '+str(tgtPort))
 
'''
c:\Python34\python.exe port_scanner.py -H localhost -p 135,136
'''