注意 This function is not implemented on Windows platforms.
Returns an array of associative arrays. Each
associative array contains
at minimum
the following keys: host, type, class, ttl.
注意 'class' key will always be "IN" indicating an IPv4 resource record.
注意 'ttl' key will contain the TTL remaining since the last time the local nameserver queried the authoritative name server.
hostname
should be a valid DNS hostname such as "www.example.com".
Reverse lookups can be generated using in-addr.arpa notation,
but
gethostbyaddr()
is more suitable for the majority of reverse lookups.
By default,
dns_get_record()
will search for any resource records associated with
hostname
. To limit the query, specify the optional
type
parameter.
type
may be any one of the following:
DNS_A
,
DNS_CNAME
,
DNS_HINFO
,
DNS_MX
,
DNS_NS
,
DNS_PTR
,
DNS_SOA
,
DNS_TXT
,
DNS_ALL
or
DNS_ANY
. The default is
DNS_ANY
.
注意 Because of excentricities in the performance of libresolv between platforms, DNS_ANY will not always return every record, the slower DNS_ALL will collect all records more reliably.
The optional third and fourth arguments to this
function,
authns
and
addtl
are passed by reference and, if given, will be populated with
Resource Records for the
Authoritative Name Servers
, and any
Additional Records
respectively. See the example below.
SOA records are the largest of the returned types.
'mname' contains the name of the machine from which the
resource records originated. 'rname' is the email address of
the administrative contact for this zone. 'serial', 'refresh',
'retry', 'expire', and 'minimum-ttl' give the traditional SOA
zone values one would expect.
注意 Per DNS standards, email addresses are given in user.host format (for example: hostmaster.example.com as opposed to hostmaster@example.com), be sure to check this value and modify if necessary before using it with a functions such as mail() .
A records will contain an 'ip' key providing
their IPv4 address.
MX records will conatin a 'pri' key indicating
priority (preference). It will also have a 'target' key which
lists the FQDN of the mail exchanger. See also
dns_get_mx()
.
CNAME, NS, and PTR records will each contain a
'target' key giving the particular location in the DNS
namespace which they refer to.
TXT records will have a 'txt' key containing the
text data associated with the named resource record.
HINFO records have two parameters: 'cpu' and 'os'
which describe the opperating environment of the specified
host. The values are given as integers, see
RFC
1010
for the meaning of these values.
Since it's very common to want the IP address of
a mail server once the MX record has been resolved,
dns_get_record()
also returns an array in
addtl
which contains associate records.
authns
is returned as well conatining a list of authoritative name
servers.
|
dns_get_mx()
, および
dns_check_record()
も参照してください。