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GeezerVison is showing github.com — doc: add esm examples to node:dns · nodejs/node@e3e2f22

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‎doc/api/dns.md‎

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+118-17Lines changed: 118 additions & 17 deletions
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Original file line numberDiff line numberDiff line change
@@ -15,13 +15,22 @@ facilities to perform name resolution. It may not need to perform any network
1515
communication. To perform name resolution the way other applications on the same
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system do, use [`dns.lookup()`][].
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18-
```js
18+
```mjs
19+
import dns from 'node:dns';
20+
21+
dns.lookup('example.org', (err, address, family) => {
22+
console.log('address: %j family: IPv%s', address, family);
23+
});
24+
// address: "2606:2800:21f:cb07:6820:80da:af6b:8b2c" family: IPv6
25+
```
26+
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```cjs
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const dns = require('node:dns');
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dns.lookup('example.org', (err, address, family) => {
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console.log('address: %j family: IPv%s', address, family);
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});
24-
// address: "93.184.216.34" family: IPv4
33+
// address: "2606:2800:21f:cb07:6820:80da:af6b:8b2c" family: IPv6
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```
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All other functions in the `node:dns` module connect to an actual DNS server to
@@ -30,7 +39,26 @@ queries. These functions do not use the same set of configuration files used by
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[`dns.lookup()`][] (e.g. `/etc/hosts`). Use these functions to always perform
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DNS queries, bypassing other name-resolution facilities.
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33-
```js
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```mjs
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import dns from 'node:dns';
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dns.resolve4('archive.org', (err, addresses) => {
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if (err) throw err;
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48+
console.log(`addresses: ${JSON.stringify(addresses)}`);
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addresses.forEach((a) => {
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dns.reverse(a, (err, hostnames) => {
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if (err) {
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throw err;
54+
}
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console.log(`reverse for ${a}: ${JSON.stringify(hostnames)}`);
56+
});
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});
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});
59+
```
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```cjs
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const dns = require('node:dns');
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dns.resolve4('archive.org', (err, addresses) => {
@@ -64,7 +92,18 @@ the servers used for a resolver using
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[`resolver.setServers()`][`dns.setServers()`] does not affect
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other resolvers:
6694

67-
```js
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```mjs
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import { Resolver } from 'node:dns';
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const resolver = new Resolver();
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resolver.setServers(['4.4.4.4']);
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100+
// This request will use the server at 4.4.4.4, independent of global settings.
101+
resolver.resolve4('example.org', (err, addresses) => {
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// ...
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});
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```
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```cjs
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const { Resolver } = require('node:dns');
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const resolver = new Resolver();
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resolver.setServers(['4.4.4.4']);
@@ -260,21 +299,38 @@ time to consult the [Implementation considerations section][] before using
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261300
Example usage:
262301

263-
```js
302+
```mjs
303+
import dns from 'node:dns';
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const options = {
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family: 6,
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hints: dns.ADDRCONFIG | dns.V4MAPPED,
307+
};
308+
dns.lookup('example.org', options, (err, address, family) =>
309+
console.log('address: %j family: IPv%s', address, family));
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// address: "2606:2800:21f:cb07:6820:80da:af6b:8b2c" family: IPv6
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// When options.all is true, the result will be an Array.
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options.all = true;
314+
dns.lookup('example.org', options, (err, addresses) =>
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console.log('addresses: %j', addresses));
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// addresses: [{"address":"2606:2800:21f:cb07:6820:80da:af6b:8b2c","family":6}]
317+
```
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```cjs
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const dns = require('node:dns');
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const options = {
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family: 6,
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hints: dns.ADDRCONFIG | dns.V4MAPPED,
268324
};
269-
dns.lookup('example.com', options, (err, address, family) =>
325+
dns.lookup('example.org', options, (err, address, family) =>
270326
console.log('address: %j family: IPv%s', address, family));
271-
// address: "2606:2800:220:1:248:1893:25c8:1946" family: IPv6
327+
// address: "2606:2800:21f:cb07:6820:80da:af6b:8b2c" family: IPv6
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273329
// When options.all is true, the result will be an Array.
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options.all = true;
275-
dns.lookup('example.com', options, (err, addresses) =>
331+
dns.lookup('example.org', options, (err, addresses) =>
276332
console.log('addresses: %j', addresses));
277-
// addresses: [{"address":"2606:2800:220:1:248:1893:25c8:1946","family":6}]
333+
// addresses: [{"address":"2606:2800:21f:cb07:6820:80da:af6b:8b2c","family":6}]
278334
```
279335

280336
If this method is invoked as its [`util.promisify()`][]ed version, and `all`
@@ -331,7 +387,15 @@ will be thrown.
331387

332388
On an error, `err` is an [`Error`][] object, where `err.code` is the error code.
333389

334-
```js
390+
```mjs
391+
import dns from 'node:dns';
392+
dns.lookupService('127.0.0.1', 22, (err, hostname, service) => {
393+
console.log(hostname, service);
394+
// Prints: localhost ssh
395+
});
396+
```
397+
398+
```cjs
335399
const dns = require('node:dns');
336400
dns.lookupService('127.0.0.1', 22, (err, hostname, service) => {
337401
console.log(hostname, service);
@@ -898,7 +962,16 @@ the servers used for a resolver using
898962
[`resolver.setServers()`][`dnsPromises.setServers()`] does not affect
899963
other resolvers:
900964

901-
```js
965+
```mjs
966+
import { Resolver } from 'node:dns/promises';
967+
const resolver = new Resolver();
968+
resolver.setServers(['4.4.4.4']);
969+
970+
// This request will use the server at 4.4.4.4, independent of global settings.
971+
const addresses = await resolver.resolve4('example.org');
972+
```
973+
974+
```cjs
902975
const { Resolver } = require('node:dns').promises;
903976
const resolver = new Resolver();
904977
resolver.setServers(['4.4.4.4']);
@@ -1028,24 +1101,45 @@ using `dnsPromises.lookup()`.
10281101

10291102
Example usage:
10301103

1031-
```js
1104+
```mjs
1105+
import dns from 'node:dns';
1106+
const dnsPromises = dns.promises;
1107+
const options = {
1108+
family: 6,
1109+
hints: dns.ADDRCONFIG | dns.V4MAPPED,
1110+
};
1111+
1112+
await dnsPromises.lookup('example.org', options).then((result) => {
1113+
console.log('address: %j family: IPv%s', result.address, result.family);
1114+
// address: "2606:2800:21f:cb07:6820:80da:af6b:8b2c" family: IPv6
1115+
});
1116+
1117+
// When options.all is true, the result will be an Array.
1118+
options.all = true;
1119+
await dnsPromises.lookup('example.org', options).then((result) => {
1120+
console.log('addresses: %j', result);
1121+
// addresses: [{"address":"2606:2800:21f:cb07:6820:80da:af6b:8b2c","family":6}]
1122+
});
1123+
```
1124+
1125+
```cjs
10321126
const dns = require('node:dns');
10331127
const dnsPromises = dns.promises;
10341128
const options = {
10351129
family: 6,
10361130
hints: dns.ADDRCONFIG | dns.V4MAPPED,
10371131
};
10381132

1039-
dnsPromises.lookup('example.com', options).then((result) => {
1133+
dnsPromises.lookup('example.org', options).then((result) => {
10401134
console.log('address: %j family: IPv%s', result.address, result.family);
1041-
// address: "2606:2800:220:1:248:1893:25c8:1946" family: IPv6
1135+
// address: "2606:2800:21f:cb07:6820:80da:af6b:8b2c" family: IPv6
10421136
});
10431137

10441138
// When options.all is true, the result will be an Array.
10451139
options.all = true;
1046-
dnsPromises.lookup('example.com', options).then((result) => {
1140+
dnsPromises.lookup('example.org', options).then((result) => {
10471141
console.log('addresses: %j', result);
1048-
// addresses: [{"address":"2606:2800:220:1:248:1893:25c8:1946","family":6}]
1142+
// addresses: [{"address":"2606:2800:21f:cb07:6820:80da:af6b:8b2c","family":6}]
10491143
});
10501144
```
10511145

@@ -1068,7 +1162,14 @@ will be thrown.
10681162
On error, the `Promise` is rejected with an [`Error`][] object, where `err.code`
10691163
is the error code.
10701164

1071-
```js
1165+
```mjs
1166+
import dnsPromises from 'node:dns/promises';
1167+
const result = await dnsPromises.lookupService('127.0.0.1', 22);
1168+
1169+
console.log(result.hostname, result.service); // Prints: localhost ssh
1170+
```
1171+
1172+
```cjs
10721173
const dnsPromises = require('node:dns').promises;
10731174
dnsPromises.lookupService('127.0.0.1', 22).then((result) => {
10741175
console.log(result.hostname, result.service);

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