xenial (3) net_adm.3erl.gz

NAME

       net_adm - Various Erlang Net Administration Routines

DESCRIPTION

       This module contains various network utility functions.

EXPORTS

       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(3erl).

       host_file() -> Hosts | {error, Reason}

              Types:

                 Hosts = [Host :: atom()]
                 Reason =
                     file:posix() |
                     badarg |
                     terminated |
                     system_limit |
                     {Line :: integer(), Mod :: module(), Term :: 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 or the Erlang  terms  on  the  file
              could not be interpreted.

       localhost() -> Name

              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:

                 Host = atom() | string() | inet:ip_address()
                 Name = string()
                 Port = integer() >= 0
                 Reason = address | file:posix()

              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.

              (arne@dunn)1> net_adm:names().
              {ok,[{"arne",40262}]}

       ping(Node) -> pong | pang

              Types:

                 Node = atom()

              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 = verbosity()
                 verbosity() = 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 nodes that were, successfully pinged.

              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 = [atom()]
                 Arg = verbosity()
                 verbosity() = silent | verbose

              As world/0,1, but the hosts are given as argument instead of being read from .hosts.erlang.

FILES

       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)