Michael Cotterell mepcotterell

Fun with `tcpdump` and `hexdump`

Here is some information that I've found/discovered from playing around with packets. The following is presented in an adhoc tutorial style. Hopepully you find it interesting.

`tcpdump`

Something that I found useful was the ability to actually capture the raw UDP packet using tcpdump utility. In the following example, we'll capture a DNS query packet and save it to a file.

Open up two terminal windows. In one window, type the following:

Assume the following:

include "range.h"

using namespace mepcotterell;

Then you can do cool stuff like this:

Git Examples

Configuration

The first thing you'll want to do is configure git on your nike account.

$ git config --global user.name "Your Name Here"
$ git config --global user.email "[email protected]"
$ git config --global --add color.ui true

Pass by Value in Java

Variable Declaration and Memory

When you declare a variable of any type (including class/reference types), some space is reserved in memory in order to hold the value of the variable. The variable is just a symbolic name for this value in memory.

Let's say we declare a long.

long x;

	object Combinatorics {

	/** Computes the multinomial coefficient (n; k_1, .., k_m)
	* where n = the sum of k_1, .., k_m.
	*
	* This is a variadic convenience function that allows
	* someone to invoke <code>multi</code> without using an
	* array. Note, however, that the variadic parameter is
	* transformed into an array when this version of
	* <code>multi</code> is invoked.

	import java.awt.Dimension;

	import javax.swing.JFrame;
	import javax.swing.JLabel;
	import javax.swing.JPanel;
	import javax.swing.UIManager;

	public class Driver {

	public static void createAndShowGUI() {

	import java.awt.Dimension;
	import java.awt.GridLayout;

	import javax.swing.JFrame;
	import javax.swing.JLabel;
	import javax.swing.JPanel;
	import javax.swing.JTextField;

	public class Form {

	#!/usr/bin/env python3

	'''
	subnet -- phatty tools for dealing with subnets

	@author: Michael E. Cotterell <[email protected]>
	'''

	import struct
	import sys

	*.class
	*~
	\#*\#
	semantic.cache

	/**
	* Linear Congruential Generator
	*
	* This implementation allows you to grab an individual number by its index. It
	* also provides a stats object for displaying statistics about the lcg.
	*
	* @see http://en.wikipedia.org/wiki/Linear_congruential_generator
	* @author Michael E. Cotterell <[email protected]>
	* @param a the multiplier
	* @param c the increment