To capture TCP Packets in Mac OS X

In Terminal  use the below command:

sudo tcpdump -s0 -n -il0 -w l0.cap

This will dump the packet info in the user’s home directory. This can be viewed using Wireshark. 

Viewing Cookie Values in Mozilla

There's an easy way to see cookie values in Mozilla Firefox [I'm trying this in Mozilla Firefox 25.0 now] :

1. Go to Tools-> Options -> Privacy
2. Under the 'History' section, there are two options to delete the cookies: 
      i.  Clear your recent history or 
      ii. Remove individual cookies

Choose the second option, which lists all the cookies. You can select the host and under each host, the cookies are listed. Once you select a cookie, its value(content) will be displayed at the bottom

That's where quickr.com stores my preferred city as bangalore. Caught Him red-handed!!! :)

Getting the next multiple of 4

To get the integer which is the next multiple of 4:

(x+3) &~0x03

If x is a multiple of 4, it will give x itself, otherwise the closest integer greater than x which is a multiple of 4.