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()
                 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)