This gem wraps the ps program, so you can get process information inside a ruby program.
The gem ships with a command called psgraph. You can use it to view a auto-refreshed ps, that can notify about cpu hungry programs. For sake of simplicity and to become more easy to test, "hungry programs" are every program that become using more than 15% of CPU in some single ps-snapshot. In Mac you could easy achieve that scrolling throught Activity Monitor.
Growl must be installed in system, since the application sends growl notifications. Requires “Listen for incoming notifications” to be enabled (in preferences pane).
To get access to processes, just use a new instance of Status class.
require 'process_status'
status = Status.new
processes = status.processes
Each process has pid, user, cpu usage and command. The library also has some helpers to deal with the process list: History, that deals with ranking processes (according with its cpu usage) and Graph, for nice History output:
history = History.new(processes)
# returns if that process (by pid) has been ranked up or down
history.process_rank(processes.first.pid)
# returns all processes with cpu usage above the Hungry Thereshold
history.hungry_processes
# gets a nice formating for history
graph = Graph.new(history)
puts graph