How do I get the first unused display in X? [closed]

Question

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.

---

Questions concerning problems with code you've written must describe the specific problem — and include valid code to reproduce it — in the question itself. See SSCCE.org for guidance.

Closed 8 years ago.

Improve this question

How do I get the first unused X display in either Python (Don't think there's a way) or {,ba,z}sh? It could return <number>, :<number>, or $(hostname):<number>).

For example:

• X session at :0, 1 returned.
• X session at :0, VNC at :1, 2 returned.
• X session at :0, QEMU at :2, 1 returned.

Answer 1

There is no good way. The least bad way I am aware of is to inspect the contents of /tmp/.X11-unix; this will contain Unix domain sockets named X0 for :0, X1 for :1, and so on. If you want a TCP socket instead, attempt to connect to port 6000 and up until you get ECONNREFUSED. Beware that both of these approaches have inherent race conditions which are AFAIK unfixable.