htop is an awesome and interactive system-monitor process-viewer. It acts as an alternative to the FreeBSD program top. It is a text-mode application and latest version works on FreeBSD based pfsense firewall too.
Install htop 2.x on pfSense
How do I use htop on pfSense firewall?
Simply type htop at the shell prompt (you may need to type rehash for the first time):
How do I show only processes of a given user?
To see only processes of a given user (say nixcraft), enter:
htop -u nixcraft
How do I show only the given PIDs?
The syntax is:
htop -p PID,[,PID,PID...]
htop -p 31151,24721
How do I disable color scheme?
To see a monochrome color scheme, enter:
See htop man page for more information: