Command line to generate URL to embed kibana's dashboard

Is there a way to generate the URL to embed the dashboard to a website without having to go to Kibana's UI and clicking on the "generate short URL" button?

At the moment the only way you might be able to do this is by querying elasticsearch directly. This could be a cool API for us to add to Kibana though, I'd encourage you to submit a ticket for it on our Github repo: https://github.com/elastic/kibana

Any idea of the syntax to do the query?

Ah I think I misread your question initially, I didn't see you were looking for a short url. There's no way to generate those without going through the UI at the moment.