-spec encode_file([dns:rr()], file:filename()) -> ok | {error, term()}.

Equivalent to encode_file(Records, Filename, #{}).

-spec encode_file([dns:rr()], file:filename(), encode_options()) -> ok | {error, term()}.

Encode a list of DNS resource records and write to a zone file with options.

-spec encode_rdata(dns:type(), dns:rrdata()) -> iodata().

Equivalent to encode_rdata(Type, RData, #{}).

-spec encode_rdata(dns:type(), dns:rrdata(), encode_options()) -> iodata().

Encode RDATA (record data) to zone file format with options.

Options (all optional):

• origin => Domain - Origin domain for relative name calculation (default: <<>>)
• relative_names => boolean() - Use @ and relative names (default: true)
• separator => binary() - Separator between fields (default: ~" ")

Examples

% Encode an MX record RDATA with custom separator
RData = #dns_rrdata_mx{preference = 10, exchange = ~"mail.example.com."},
RDataStr = dns_zone:encode_rdata(?DNS_TYPE_MX, RData, #{separator => ~"\t"}).
% Returns: "10\tmail.example.com."

% Encode an NS record RDATA with relative names
RData = #dns_rrdata_ns{dname = ~"ns1.example.com."},
RDataStr = dns_zone:encode_rdata(?DNS_TYPE_NS, RData, #{
    origin => ~"example.com.",
    relative_names => true
}).
% Returns: "ns1" (if ns1 is under example.com.)

-spec encode_rr(dns:rr()) -> iodata().

Encode a single DNS resource record to zone file format.

Returns a string representing the record in zone file format.

Examples

RR = #dns_rr{
    name = ~"www.example.com.",
    type = ?DNS_TYPE_A,
    class = ?DNS_CLASS_IN,
    ttl = 3600,
    data = #dns_rrdata_a{ip = {192, 0, 2, 1}}
},
Line = dns_zone:encode_rr(RR).
% Returns: "www.example.com. 3600 IN A 192.0.2.1"

-spec encode_rr(dns:rr(), encode_options()) -> iodata().

Encode a single DNS resource record to zone file format with options.

Options (all optional):

• origin => Domain - Origin domain for relative name calculation
• relative_names => boolean() - Use @ and relative names (default: true)

• ttl_format => seconds | units - TTL format: 3600 or 1h (default: seconds)

• omit_class => boolean() - Omit IN class (default: false)

Examples

RR = #dns_rr{
    name = ~"www.example.com.",
    type = ?DNS_TYPE_A,
    class = ?DNS_CLASS_IN,
    ttl = 3600,
    data = #dns_rrdata_a{ip = {192, 0, 2, 1}}
},
Line = dns_zone:encode_rr(RR, #{origin => ~"example.com.", relative_names => true}).
% Returns: "www 3600 IN A 192.0.2.1"

-spec encode_string([dns:rr()]) -> iodata().

Equivalent to encode_string(Records, #{}).

-spec encode_string([dns:rr()], encode_options()) -> iodata().

Encode a list of DNS resource records to zone file format with options.

Examples

Records = [...],
ZoneData = dns_zone:encode_string(Records, #{
    origin => ~"example.com",
    default_ttl => 3600,
    relative_names => true
}).

-spec format_error(error_detail()) -> iolist().

Format a parse error into a human-readable string.

Takes an error from parse_file/1,2 or parse_string/1,2 and returns a formatted string suitable for display to users.

Examples

case dns_zone:parse_file("bad.zone") of
    {ok, Records} -> ok;
    {error, Error} ->
        io:format("~s", [dns_zone:format_error(Error)])
end.

-spec parse_file(file:filename()) -> {ok, [dns:rr()]} | {error, error_detail()}.

Parse a zone file from disk.

Returns {ok, Records} where Records is a list of #dns_rr{} records, or {error, Reason} if parsing fails.

Examples

{ok, Records} = dns_zone:parse_file("/path/to/zone.db").

-spec parse_file(file:filename(), parse_options()) -> {ok, [dns:rr()]} | {error, error_detail()}.

Parse a zone file from disk with options.

Options (all optional):

• origin => Domain - Set the initial $ORIGIN
• default_ttl => TTL - Set the default TTL
• default_class => Class - Set the default class (defaults to IN)
• base_dir => Dir - Set base directory for $INCLUDE directives

Examples

{ok, Records} = dns_zone:parse_file("zone.db", #{origin => ~"example.com."}).

{ok, Records} = dns_zone:parse_file("zone.db", #{
    origin => ~"example.com.",
    default_ttl => 3600
}).

-spec parse_string(binary() | string()) -> {ok, [dns:rr()]} | {error, error_detail()}.

Parse zone file content from a string or binary.

Examples

ZoneData = ~"example.com. IN A 192.0.2.1",
{ok, Records} = dns_zone:parse_string(ZoneData).

-spec parse_string(binary() | string(), parse_options()) -> {ok, [dns:rr()]} | {error, error_detail()}.

Parse zone file content from a string or binary with options.