Port scanner in bash (TCP)

First, source the functions:

. scanner

Execute the scan with the following syntax:

scan <host> <port, ports, port-range>

Examples:

scan google.com 80

scan google.com 78-82

scan google.com 25,80,443

user@host:~/bash-port-scanner$ . scanner
user@host:~/bash-port-scanner$ scan google.com 78-82
78/tcp closed
79/tcp closed
80/tcp open
81/tcp closed
82/tcp closed
user@host:~/bash-port-scanner$ scan google.com 25,80,443
25/tcp closed
80/tcp open
443/tcp open

Original concept found here: http://www.catonmat.net/blog/tcp-port-scanner-in-bash/

I made a couple tweaks in the formatting. I plan to abstract it a little further to incorporate UDP.