net.3erl - Man Page

Network interface.


This module provides an API for the network interface.


There is currently no support for Windows.


The content of this file is only valid if the system has been built with 'socket' (esock) support, which is the default.

Data Types

address_info() = 
    #{family := term(),
      socktype := term(),
      protocol := term(),
      address := term()}
ifaddrs() = 
    #{name := string(),
      flags := [ifaddrs_flag()],
      addr := socket:sockaddr(),
      netmask := socket:sockaddr(),
      broadaddr := socket:sockaddr(),
      dstaddr := socket:sockaddr()}

This type defines all addresses (and flags) associated with the interface.

Not all fields of this map has to be present. The flags field can be used to test for some of the fields. For example broadaddr will only be present if the broadcast flag is present in flags.

ifaddrs_flag() = 
    up | broadcast | debug | loopback | pointopoint | notrailers |
    running | noarp | promisc | master | slave | multicast |
    portsel | automedia | dynamic
ifaddrs_filter() = 
    all | default | inet | inet6 | packet |
    ifaddrs_filter_map() |

All interfaces


Interfaces with address family inetandinet6

inet | inet6 | packet:

Interfaces with only the specified address family

ifaddrs_filter_map() = 
    #{family := default | inet | inet6 | packet | all,
      flags := any | [ifaddrs_flag()]}

The family field can only have the (above) specified values (and not all the values of socket:domain()).

The use of the flags field is that any flag provided must exist for the interface.

For example, if family is set to inet and flags to [broadcast, multicast] only interfaces with address family inet and the flags broadcast and multicast will be listed.

ifaddrs_filter_fun() = fun((ifaddrs()) -> boolean())

For each ifaddrs entry, return either true to keep the entry or false to discard the entry.

For example, to get an interface list which only contains non-loopback inet interfaces:

	net:getifaddrs(fun(#{addr  := #{family := inet},
	                     flags := Flags}) ->
			       not lists:member(loopback, Flags);
			  (_) ->
name_info() = #{host := string(), service := string()}
name_info_flags() = [name_info_flag() | name_info_flag_ext()]
name_info_flag() = 
    namereqd | dgram | nofqdn | numerichost | numericserv
name_info_flag_ext() = idn
network_interface_name() = string()
network_interface_index() = integer() >= 0


gethostname() -> {ok, HostName} | {error, Reason}

HostName = string()
Reason = term()

Returns the name of the current host.

getnameinfo(SockAddr) -> {ok, Info} | {error, Reason}
getnameinfo(SockAddr, Flags) -> {ok, Info} | {error, Reason}

SockAddr = term()
Flags = name_info_flags() | undefined
Info = name_info()
Reason = term()

Address-to-name translation in a protocol-independant manner.

This function is the inverse of getaddrinfo. It converts a socket address to a corresponding host and service.

getaddrinfo(Host) -> {ok, Info} | {error, Reason}
getaddrinfo(Host, Service :: undefined) ->
               {ok, Info} | {error, Reason}
getaddrinfo(Host :: undefined, Service) ->
               {ok, Info} | {error, Reason}
getaddrinfo(Host, Service) -> {ok, Info} | {error, Reason}

Host = Service = string()
Info = [address_info()]
Reason = term()

Network address and service translation.

This function is the inverse of getnameinfo. It converts host and service to a corresponding socket address.

One of the Host and Service may be undefined but not both.

getifaddrs() -> {ok, IfAddrs} | {error, Reason}
getifaddrs(Filter) -> {ok, IfAddrs} | {error, Reason}
getifaddrs(Namespace) -> {ok, IfAddrs} | {error, Reason}
getifaddrs(Filter, Namespace) -> {ok, IfAddrs} | {error, Reason}

Filter = ifaddrs_filter()
Namespace = file:filename_all()
IfAddrs = [ifaddrs()]
Reason = term()

Get interface addresses.

This function is used to get the machines interface addresses, possibly filtered according to Filter.

By default, a filter with the content: #{family => default, flags => any} is used. This will return all interfaces with adresses in the inet and inet6 families.

if_name2index(Name) -> {ok, Idx} | {error, Reason}

Name = network_interface_name()
Idx = network_interface_index()
Reason = term()

Mappings between network interface names and indexes.

if_index2name(Idx) -> {ok, Name} | {error, Reason}

Idx = network_interface_index()
Name = network_interface_name()
Reason = term()

Mappings between network interface index and names.

if_names() -> Names | {error, Reason}

Names = [{Idx, If}]
Idx = network_interface_index()
If = network_interface_name()
Reason = term()

Get network interface names and indexes.


kernel 8.0 Ericsson AB Erlang Module Definition