IPython notebook: Can I check if there is a server active for a particular directory?

Question

Before I open an IPython notebook, I'd like to check whether it is in a directory that is already being served by a server process. The goal is to connect to that server instead of launching yet another server for the same directory.

Background: I often work with IPython notebooks in several different directories, and since one server can only handle one directory hierarchy, I have to launch several separate notebook servers. As far as I know this cannot be avoided unless I move all my notebooks into the same directory hierarchy, right? But at least I want to avoid launching more servers than necessary. If I could check for the existence of a suitable server (and get the connection ID), I could connect to it instead of launching a new one.

Answer 1

Running ipython notebook help or ipython notebook -h gives the answer. Who knew?

Subcommands

Subcommands are launched as ipython-script.py cmd [args]. For information on using subcommand 'cmd', do: ipython cmd -h.

list  
    List currently running notebook servers in this profile.

Curiously the above list is both incomplete (the subcommand help is not mentioned) and incorrect: The correct invocation is ipython notebook list, not ipython list.

% ipython notebook list