cl-epmd

Version: 0.2.0

cl-epmd is a Common Lisp library including an EPMD (Erlang Port Mapper Daemon) client and server.

How to install

Use Quicklisp to install cl-epmd.

> (ql:quickload :epmd)

Dependencies

• binary-data
• usocket

Optional dependencies:

• FiveAM (unit-tests)
• FLEXI-STREAMS (for testing)

How to run the unit-tests

> (ql:quickload :epmd-test)
...
> (epmd-test:run-all-tests)

Server API

[Function]
start host => nil

Start an EPMD server listening on host. This function will not return until the server is stopped.

Client API

Requests

[Function]
lookup-node node-name &optional host => node-info

Requests node information and distribution port for the node node-name registered at the EPMD server running at host.

The default value of host is "localhost".

lookup-node returns a node-info object if a node with the requested name is registered on the server, otherwise nil is returned.

[Function]
print-all-registered-nodes &optional host stream => t

Requests a list of all registered nodes on EPMD server at host and prints them to stream.

The default value of host is "localhost". The default stream is standard output.

[Function]
publish node-name listening-port => epmd-connection

Register at the EPMD server running at localhost. The node will be registered as node-name listening to listening-port.

publish returns an epmd-connection object that the application must keep as long as it is registered on the server.

Node info

[Standard class]
node-info

An object of this type is returned by lookup-node containing information about another node. The most interesting part of this object is node-port which is needed to connect to the corresponding node.

[Accessors]
node-name
node-host
node-port
node-type
node-protocol
node-highest-version
node-lowest-version
node-extra-field

EPMD connection

[Standard class]
epmd-connection

An object of this type is returned by publish after a successful registration. The application must keep track of this object as long as it is registered on the EPMD server.

[Accessors]
published-node-name
published-node-port

[Function]
published-p epmd-connection => boolean

This functions returns true if the connection to the EPMD server is still open, which indicates that the node is registered and published.

[Function]
unpublish epmd-connection => boolean

This functions closes the connection to the EPMD server and unregisters the node.