lists

Lists

Building and reading arrays, and the tools of the list domain, on the TCP ports a Linux listens on, against those expected.

How to read it

• $ports = array();: an empty array. An array is a value: passing it to a function or another variable copies it.
• $ports[$m[2]][$m[1]] = true;: writing under a key that is missing creates it, and what is missing above it. The variable itself must exist first.
• list.count: the number of elements. list.has($ports, $port): is there an element under this key. list.get($closed, 0, ''): the element, or the default when the key is missing.
• list.add($closed, $port): the list with one more element at its end. $a[] = $x does not exist in Keen.
• A key is a text: $ports[22] and $ports['22'] are the same element.

To adapt it

• foreach ($ports as $port => $addresses) goes over the keys and the values (see examples/watches/deviate).
• To return one value per port, declare a per (see examples/mechanics/selection).