Ruff 1.6.0 Documentation
Table of Contents
DNS#
The dns
module contains functions to perform name resolution.
dns.lookup(hostname[, options], callback)#
Resolves a hostname (e.g. 'nanchao.org'
) into the first found A (IPv4) record.
options
can be an object or integer. If options
is not provided, then IPv4 is
valid. If options
is an integer, then it must be 4
.
Alternatively, options
can be an object containing these properties:
family
{Number} - The record family. If present, must be the integer4
. If not provided, IP v4 is accepted.all
: {Boolean} - Whentrue
, the callback returns all resolved addresses in an array, otherwise returns a single address. Defaults tofalse
.
All properties are optional. An example usage of options is shown below.
{
family: 4,
all: false
}
The callback
function has arguments (err, address, family)
. address
is a
string representation of an IPv4. family
is the integer 4
and denotes the family
of address
(not necessarily the value initially passed to lookup
).
With the all
option set to true
, the arguments change to
(err, addresses)
, with addresses
being an array of objects with the
properties address
and family
.
On error, err
is an [Error
][] object, where err.code
is the error code.