tcp-scanner.py

from socket import * #importing everything from bluit in python module socket
import optparse      #importing optparse library for accepting arguments
import threading     # threading library for simultaneous execution of program or functions
import time
def portScan(host, port):
    try:
        s = socket(AF_INET, SOCK_STREAM) #creating an object of class socket AF_INET for ipv4 and AF_INET6 for ipv6
                                         #SOCK_STREAM is for tcp(protocol) and SOCK_DGRAM id for udp(protocol)
        s.connect((host, int(port)))     # connecting to the socket with target host and port
        print(host + " tcp/" + str(port) + " open")
        s.close()
        
    except:
        print(host + " tcp/" + str(port) + " closed") # print this if unable to connect (meaning port closed)
        
        
def main():
    
    parser = optparse.OptionParser("uasge%prog " + "-H <specify target host> -p <specify ports separated by ',' > ")
    parser.add_option("-H" , '--host' , dest = 'targethost' , type = 'string' , help = 'specify target hsot')
    parser.add_option("-p", "--ports", dest = 'targetports', type = 'string', help = 'specify target ports separated by "," ')
    
    option ,  args = parser.parse_args() # this functions returns the arguments received inside object options
    
    thost = option.targethost # accessing arguments 
    tports = str(option.targetports).split(",")
    
    if thost ==  None or tports[0] == None:
        print(parser.usage)        #prints the usage defined inside the OptionParser class Above as string
        exit(0) 
    
    
    setdefaulttimeout(1)           # close connection if no response is received 
    host_ip = gethostbyname(thost) # get the target ip using target domain 
    
    for port in tports:
        t = threading.Thread(target=portScan, args=(thost,port)) # creating a portScann Function thread for each port in port list
        t.start() #Starting the thread
        
main()
time.sleep(4)