erl_epmd - Erlang interface towards epmd
Please see following description for synopsis
erl_epmd(3) Erlang Module Definition erl_epmd(3)
NAME
erl_epmd -
Erlang interface towards epmd
DESCRIPTION
This module communicates with the EPMD daemon, see epmd. To implement
your own epmd module please see ERTS User's Guide: How to Implement an
Alternative Node Discovery for Erlang Distribution
EXPORTS
start_link() -> {ok, pid()} | ignore | {error, term()}
This function is invoked as this module is added as a child of
the erl_distribution supervisor.
register_node(Name, Port) -> Result
register_node(Name, Port, Driver) -> Result
Types:
Name = string()
Port = integer() >= 0
Driver = inet_tcp | inet6_tcp | inet | inet6
Creation = integer() >= 0 | -1
Result = {ok, Creation} | {error, already_registered} |
term()
Registers the node with epmd and tells epmd what port will be
used for the current node. It returns a creation number. This
number is incremented on each register to help differentiate a
new node instance connecting to epmd with the same name.
After the node has successfully registered with epmd it will
automatically attempt reconnect to the daemon if the connection
is broken.
port_please(Name, Host) ->
{port, Port, Version} |
noport | closed |
{error, term()}
port_please(Name, Host, Timeout) ->
{port, Port, Version} |
noport | closed |
{error, term()}
Types:
Name = atom() | string()
Host = atom() | string() | inet:ip_address()
Timeout = integer() >= 0 | infinity
Port = Version = integer() >= 0
Requests the distribution port for the given node of an EPMD
instance. Together with the port it returns a distribution pro-
tocol version which has been 5 since Erlang/OTP R6.
listen_port_please(Name, Host) -> {ok, Port}
Types:
Name = atom() | string()
Host = atom() | string() | inet:ip_address()
Port = integer() >= 0
Called by the distribution module to get which port the local
node should listen to when accepting new distribution requests.
address_please(Name, Host, AddressFamily) ->
Success | {error, term()}
Types:
Name = string()
Host = string() | inet:ip_address()
AddressFamily = inet | inet6
Port = Version = integer() >= 0
Success =
{ok, inet:ip_address()} |
{ok, inet:ip_address(), Port, Version}
Called by the distribution module to resolves the Host to an IP
address of a remote node.
As an optimization this function may also return the port and
version of the remote node. If port and version are returned
port_please/3 will not be called.
names(Host) -> {ok, [{Name, Port}]} | {error, Reason}
Types:
Host = atom() | string() | inet:ip_address()
Name = string()
Port = integer() >= 0
Reason = address | file:posix()
Called by net_adm:names/0. Host defaults to the localhost.
Returns the names and associated port numbers of the Erlang
nodes that epmd registered at the specified host. Returns
{error, address} if epmd is not operational.
Example:
(arne@dunn)1> erl_epmd:names(localhost).
{ok,[{"arne",40262}]}
Ericsson AB kernel 8.2 erl_epmd(3)