![[Ericsson AB]](min_head.gif)
This module contains various network utility functions.
dns_hostname(Host) -> {ok, Name} | {error, Host}
Types:
Host = atom() | string()
Name = string()
Returns the official name of Host, or
{error, Host} if no such name is found. See also
inet(3).
host_file() -> Hosts | {error, Reason}
Types:
Hosts = [Host]
Host = atom()
Reason = term()
Reads the .hosts.erlang file, see the section
Files below. Returns the hosts in this file as a
list, or returns {error, Reason} if the file could not
be read. See file(3) for possible values of
Reason.
Types:
Name = string()
Returns the name of the local host. If Erlang was started
with the -name command line flag, Name is
the fully qualified name.
names() -> {ok, [{Name, Port}]} | {error, Reason}
names(Host) -> {ok, [{Name, Port}]} | {error, Reason}
Types:
Name = string()
Port = int()
Reason = address | term()
Similar to epmd -names, see epmd(1).
Host defaults to the local host. Returns the names and
associated port numbers of the Erlang nodes that epmd
at the specified host has registered.
Returns {error, address} if epmd is not
running. See inet(3) for other possible values of
Reason.
(arne@dunn)1> net_adm:names().
{ok,[{"arne",40262}]}
Types:
Node = node()
Tries to set up a connection to Node. Returns
pang if it fails, or pong if it is successful.
world() -> [node()]
world(Arg) -> [node()]
Types:
Arg = silent | verbose
This function calls names(Host) for all hosts which
are specified in the Erlang host file .hosts.erlang,
collects the replies and then evaluates ping(Node) on
all those nodes. Returns the list of all found nodes,
regardless of the return value of ping(Node).
Arg defaults to silent. If Arg ==
verbose, the function writes information about which
nodes it is pinging to stdout.
This function can be useful when a node is started, and the names of the other nodes in the network are not initially known.
Failure: {error, Reason} if host_file()
returns {error, Reason}.
world_list(Hosts) -> [node()]
world_list(Hosts, Arg) -> [node()]
Types:
Hosts = [Host]
Host = atom()
Arg = silent | verbose
As world/0,1, but the hosts are given as argument
instead of being read from .hosts.erlang.
The .hosts.erlang file consists of a number of host names
written as Erlang terms. It is looked for in the current work
directory, the user's home directory, and $OTP_ROOT
(the root directory of Erlang/OTP), in that order.
The format of the .hosts.erlang file must be one host
name per line. The host names must be within quotes as shown in
the following example:
'super.eua.ericsson.se'.
'renat.eua.ericsson.se'.
'grouse.eua.ericsson.se'.
'gauffin1.eua.ericsson.se'.
^ (new line)