Module dgram

dgram is one of the basic modules, mainly used to implement UDP data packet socket encapsulation.

Steps for usage:

1. First, introduce the dgram module through the following statement.

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   var dgram = require('dgram');
   

2. Create a UDP packet socket instance.

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   var sock = dgram.createSocket('udp4');
   

3. Register the data reception event message callback function for the UDP packet socket.

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   sock.on('message', function (msg, rinfo) {
   // process received message
   });
   

4. Sends a UDP packet message to the specified destination address.

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   var msg = ...; // message to send
   var port = ...; // destination port
   var host = ...; // destination host
   var bytes = sock.send(msg, 0, msg.length, port, host);
   console.log('UDP message sent to ' + host + ':' + port);
   

object

Socket

dgram.SocketThe object is a package function that encapsulates the functionEventEmitter. SeeDgramSocket

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DgramSocket dgram.Socket;

dgram.SocketInstance is given bydgram.createSocket() created. createdgram.SocketInstances do not need to use the new keyword.

static function

createSocket

Createdgram.Socketobject

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static DgramSocket dgram.createSocket(Object opts);

Call parameters:

• opts: Object,

Return results:

• DgramSocket, returns the createdSocketobject

Options allowed by opts are:

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{
    "type": "udp4" | "udp6", // socket type
    "reuseAddr": true | false, // reuse address, default is false
    "ipv6Only": true | false, // only accept IPv6 packets, default is false
    "recvBufferSize": 1024, // specify the size of the receive buffer
    "sendBufferSize": 1024 // specify the size of the send buffer
}

---

Createdgram.Socketobject

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static DgramSocket dgram.createSocket(Object opts,
    Function callback);

Call parameters:

• opts: Object,
• callback: Function, adds a listener for the 'message' event.

Return results:

• DgramSocket, returns the createdSocketobject

Options allowed by opts are:

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{
    "type": "udp4" | "udp6", // socket type
    "reuseAddr": true | false, // reuse address, default is false
    "ipv6Only": true | false, // only accept IPv6 packets, default is false
    "recvBufferSize": 1024, // specify the size of the receive buffer
    "sendBufferSize": 1024 // specify the size of the send buffer
}

---

Createdgram.Socketobject

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static DgramSocket dgram.createSocket(String type);

Call parameters:

• type: String, socket family, 'udp4' or 'udp6'.

Return results:

• DgramSocket, returns the createdSocketobject

---

Createdgram.Socketobject

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static DgramSocket dgram.createSocket(String type,
    Function callback);

Call parameters:

• type: String, socket family, 'udp4' or 'udp6'.
• callback: Function, adds a listener for the 'message' event.

Return results:

• DgramSocket, returns the createdSocketobject