Here is a simple nice command to figure out how many processors or cores are assigned to a *unix machine.

cat /proc/cpuinfo | grep processor | wc -l


This basically processes the lines containing the processor information and counts them up for you, I got 4.  Try the same commands without the word count (wc) pipe and you can get much more information in detail.

cat /proc/cpuinfo | grep processor


By trying the above I got the following:

processor	: 0
processor	: 1
processor	: 2
processor	: 3


Try it even further without the grep for processor and you get lots of detailed information about your system.  Try it out!

cat /proc/cpuinfo