How to change command line for execution

Question

I wrote a simple code for a chat client and chat server (a separate code for the client and one for the server). My server currently executes with the command line

python chatserve.py <port number>

Just found out that class requirement is that the program starts with the following command line:

./chatclient <portnumber>

How do I convert? I would greatly appreciate any tips/help. Thank you!

(To clarify any confusion, the execution of my chat client also needs a ./chatclient in its command line, but since that part of the code was written in C, I was able to figure out how to get it to execute with specific command lines. I'm not as familiar with Python unfortunately.)

Here is the code:

#!/bin/python

from socket import *
import sys

#initiate chat with client
def chat(connectionsocket, clientname, username):
    to_send = ""
    while 1:    # continue chat until break
        # get characters from the user
        received = connectionsocket.recv(501)[0:-1]

        # if we received nothing, print close message and break
        if received == "":
            print "Closed connection.  Wait for new connection..."
            break

        # print client username and message
        print "{}> {}".format(clientname, received)

        # get server input and send to client
        to_send = ""
        while len(to_send) == 0 or len(to_send) > 500:
            to_send = raw_input("{}> ".format(username))

        # special "\quit" message 
        if to_send == "\quit":
            print "Closed connection.  Wait for new connection..."
            break
        connectionsocket.send(to_send)

#initiate handshake with client
def handshake(connectionsocket, username):
    # get the client username
    clientname = connectionsocket.recv(1024)

    # send server username to the client
    connectionsocket.send(username)

    return clientname

#execution
if __name__ == "__main__":

    # If wrong number of arguments, print error message and exit
    if len(sys.argv) != 2:
        print "Error: no port number input"
        exit(1)

    # get port number and create TCP socket
    serverport = sys.argv[1]
    serversocket = socket(AF_INET, SOCK_STREAM)

    # bind socket to port
    serversocket.bind(('', int(serverport)))

    # listen on port for incoming messages
    serversocket.listen(1)

    # get username
    username = ""
    while len(username) == 0 or len(username) > 10:
        username = raw_input("Enter username (10 characters or less): ")
        print "Receiving incoming messages..."

    # continue receiving incoming messages until close
    while 1:
        # create new socket for incoming connection
        connectionsocket, address = serversocket.accept()

        # print connection message 
        print "Receiving connection on address {}".format(address)

        # initiate handshake and chat with incoming connection
        chat(connectionsocket, handshake(connectionsocket, username),     username)

        # close connection
        connectionsocket.close()

Answer 1

Follow these steps:

1. Rename the filename to: chatserve
2. Add the following command in the first line of your code: #!/usr/bin/python or #!/usr/bin/python2 or #!/usr/bin/python3
3. Give him permission to execute: chmod +x chatserve