Friday, November 19, 2010

Bouncing Orbs

I recently finished a major milestone for a C++/SDL game development course. It is my first mini-game/animation. It was an awesome programming  experience. It was amazing to learn things like parallax scrolling, creating explosions, save/restore of animation state in Xml(expat). Thank you Dr. Malloy.

Tuesday, November 2, 2010

Python - Writing a traceroute using sockets

I recently learned, how to write a traceroute using socket programming in python. I am sharing it below. I don't take any credit for the code. I may have picked bits and pieces from various different resources on the Internet, as a part of my learning process. It's not very elegant but demonstrates the purpose. Perhaps, some day I can improve it and add few enhancements to it.

import sys
import socket

def traceroute(dest_name):
    dest_addr = socket.gethostbyname(dest_name)
    port = 33434
    max_hops = 30
    print dest_name
    icmp = socket.getprotobyname('icmp')
    udp = socket.getprotobyname('udp')
    ttl = 1
    while True:
        print ttl,
        recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
        send_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
        send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)
        recv_socket.bind(("", port))
        send_socket.sendto("", (dest_name, port))
        curr_addr = None
        curr_name = None
            _, curr_addr = recv_socket.recvfrom(512)
            curr_addr = curr_addr[0]

                curr_name = socket.gethostbyaddr(curr_addr)[0]
            except socket.error:
                curr_name = curr_addr
        except socket.error:

        if curr_addr is not None:
            curr_host = "%s (%s)" % (curr_name, curr_addr)
            curr_host = "*"
        print "%d\t%s" % (ttl, curr_host)

        ttl += 1
        if curr_addr == dest_addr or ttl > max_hops:

if __name__ == "__main__":

Can be executed as -

>sudo ./