1net_adm(3)                 Erlang Module Definition                 net_adm(3)
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3
4

NAME

6       net_adm - Various Erlang net administration routines.
7

DESCRIPTION

9       This module contains various network utility functions.
10

EXPORTS

12       dns_hostname(Host) -> {ok, Name} | {error, Host}
13
14              Types:
15
16                 Host = atom() | string()
17                 Name = string()
18
19              Returns  the  official name of Host, or {error, Host} if no such
20              name is found. See also inet(3).
21
22       host_file() -> Hosts | {error, Reason}
23
24              Types:
25
26                 Hosts = [Host :: atom()]
27                 Reason =
28                     file:posix() |
29                     badarg | terminated | system_limit |
30                     {Line :: integer(), Mod :: module(), Term :: term()}
31
32              Reads file .hosts.erlang, see section Files. Returns  the  hosts
33              in this file as a list. Returns {error, Reason} if the file can‐
34              not be read or the Erlang terms on the  file  cannot  be  inter‐
35              preted.
36
37       localhost() -> Name
38
39              Types:
40
41                 Name = string()
42
43              Returns  the  name of the local host. If Erlang was started with
44              command-line flag -name, Name is the fully qualified name.
45
46       names() -> {ok, [{Name, Port}]} | {error, Reason}
47
48       names(Host) -> {ok, [{Name, Port}]} | {error, Reason}
49
50              Types:
51
52                 Host = atom() | string() | inet:ip_address()
53                 Name = string()
54                 Port = integer() >= 0
55                 Reason = address | file:posix()
56
57              Similar to epmd -names, see erts:epmd(1). Host defaults  to  the
58              local host. Returns the names and associated port numbers of the
59              Erlang nodes that epmd registered at the specified host. Returns
60              {error, address} if epmd is not operational.
61
62              Example:
63
64              (arne@dunn)1> net_adm:names().
65              {ok,[{"arne",40262}]}
66
67       ping(Node) -> pong | pang
68
69              Types:
70
71                 Node = atom()
72
73              Sets  up a connection to Node. Returns pong if it is successful,
74              otherwise pang.
75
76       world() -> [node()]
77
78       world(Arg) -> [node()]
79
80              Types:
81
82                 Arg = verbosity()
83                 verbosity() = silent | verbose
84
85              Calls names(Host) for all hosts that are specified in the Erlang
86              host  file  .hosts.erlang, collects the replies, and then evalu‐
87              ates ping(Node) on all those nodes.  Returns  the  list  of  all
88              nodes that are successfully pinged.
89
90              Arg  defaults  to silent. If Arg == verbose, the function writes
91              information about which nodes it is pinging to stdout.
92
93              This function can be useful when a  node  is  started,  and  the
94              names of the other network nodes are not initially known.
95
96              Returns {error, Reason} if host_file() returns {error, Reason}.
97
98       world_list(Hosts) -> [node()]
99
100       world_list(Hosts, Arg) -> [node()]
101
102              Types:
103
104                 Hosts = [atom()]
105                 Arg = verbosity()
106                 verbosity() = silent | verbose
107
108              Same  as  world/0,1, but the hosts are specified as argument in‐
109              stead of being read from .hosts.erlang.
110

FILES

112       File .hosts.erlang consists of a number of host names written as Erlang
113       terms.  It is looked for in the current work directory, the user's home
114       directory, and $OTP_ROOT (the root directory of  Erlang/OTP),  in  that
115       order.
116
117       The  format  of  file .hosts.erlang must be one host name per line. The
118       host names must be within quotes.
119
120       Example:
121
122       ^ (new line)
123
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125
126Ericsson AB                      kernel 8.1.3                       net_adm(3)