habit

// The watch "habit": it raises when a value leaves its habit for this host, at this hour and on this day
// of the week. It learns the habit first: until then it raises nothing, and says it is learning.
// The collector counts the processes of a Linux, by SSH.
need('protocol:ssh');

output('processes', 'number', array('label' => 'Processes'));

// sensitivity: low, normal or high. floor: under 50 processes it never raises, whatever the habit.
watch.habit('unusual', 'Unusual number of processes', 'processes', array(
    'help'        => 'Warns when the number of processes is far from what this host usually runs at this hour.',
    'sensitivity' => 'low',
    'floor'       => 50,
));

// One line per process, no header.
$read = ssh.run('ps -e -o pid=');
value('processes', list.count(text.lines($read['output'])));