Journalctl

This is a module for accessing the all mighty Systemd Journal and its handy dandy key-value store hidden behind every log line. In the background it spawns a journalctl process with the output format json and parses the serialised object stream.

API

Require the module and create a new instance:

``js
const Journalctl = require('journalctl');
const journalctl = new Journalctl([opts]);
`

The optional object opts can have the following properties:
* identifier: Just output logs of the given syslog identifier (cf. man journalctl, option '-t')
* unit: Just output logs originated from the given unit file (cf. man journalctl, option '-u')
* filter: An array of matches to filter by (cf. man journalctl, matches)
* all: Show all fields in full, even if they include unprintable characters or are very long. (cf. man journalctl, option '-a')
* lines: Show the most recent journal events and limit the number of events shown (cf. man journalctl, option '-n')
* since: Start showing entries on or newer than the specified date (cf. man journalctl, option '-S')

$3

`js
journalctl.on('event', (event) => {});
`

Is fired on every log event and hands over the object event describing the event. (Oh boy ... so many events in one sentence ...)

$3

`js
journalctl.stop([callback]);
`

Stops journalctl and calls the optional callback` once everything has been killed.