Home / References / ESP32 Library / WiFiClientSecure
Description
The remotePort
method in the ESP32 WiFiClient Library returns the port number of the remote server or peer to which the client is currently connected. This method is invaluable for confirming the destination port of a connection, aiding in debugging, or logging network interactions in your projects.
Syntax and Usage
The remotePort
method is invoked on a WiFiClient
object to retrieve the remote server’s port number. Below is the syntax and a code snippet demonstrating its usage:
uint16_t port = client.remotePort();
Here’s how this method can be used:
- Without Arguments: Call the method on an active
WiFiClient
instance to obtain the remote port number as an integer.
For practical applications and examples of this method, please consult the “Example Code” section on this page. This section provides comprehensive guidance to help you better understand and apply the method effectively.
Argument(s)
This method does not require any arguments. It relies entirely on the current connection state of the WiFiClient
object.
Return Value
The remotePort
method returns an unsigned 16-bit integer (uint16_t
) representing the port number of the remote server. If the client is not connected, it typically returns 0.
Example Codes
Below is an example demonstrating how to use the remotePort
method in a practical scenario. This corresponds to the usage outlined in Section 2.
Example: Retrieving and Displaying the Remote Port Number
This example connects an ESP32 to www.httpbin.org
on port 80, retrieves the remote server’s port number using remotePort
, and prints it to the Serial Monitor for confirmation.
/*
* Author: Avant Maker
* Date: February 24, 2025
* Version: 1.0
*
* Description: This example connects an ESP32 to
* www.httpbin.org on port 80, retrieves the remote
* server’s port number using ESP32 WiFiClient Library's
* remotePort, and prints it to the Serial Monitor for
* confirmation.
*
* License: MIT
*
* Code Source: This example code is sourced from the Comprehensive
* Guide to the ESP32 Arduino Core Library, accessible on
* AvantMaker.com. For additional code examples and in-depth
* documentation related to the ESP32 Arduino Core Library,
* please visit:
*
* https://avantmaker.com/references/esp32-arduino-core-index/
*
* AvantMaker.com, your premier destination for all things
* DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated
* to empowering makers, learners, and enthusiasts with the resources
* they need to bring their innovative ideas to life.
*/
#include <WiFi.h>
const char* ssid = "your-SSID"; // Replace with your Wi-Fi SSID
const char* password = "your-PASSWORD"; // Replace with your Wi-Fi password
const char* host = "www.httpbin.org";
const int port = 80;
void setup() {
Serial.begin(115200);
// Connect to WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("\nConnected to WiFi");
// Create a WiFiClient instance
WiFiClient client;
// Connect to the server
if (client.connect(host, port)) {
Serial.println("Connected to server");
// Get the remote port number
uint16_t remotePortNum = client.remotePort();
Serial.print("Remote Port Number: ");
Serial.println(remotePortNum);
// Send HTTP GET request
client.println("GET /get HTTP/1.1");
client.println("Host: www.httpbin.org");
client.println("Connection: close");
client.println();
// Wait for server response
while (client.connected()) {
if (client.available()) {
String line = client.readStringUntil('\n');
Serial.println(line);
}
}
client.stop();
Serial.println("Disconnected");
} else {
Serial.println("Connection failed");
}
}
void loop() {
// Nothing to do here
}
Explanation: The ESP32 connects to a WiFi network and establishes a TCP connection to www.httpbin.org
on port 80. The remotePort
method retrieves the server’s port number (expected to be 80), which is then printed to the Serial Monitor. This allows makers to verify the connection’s destination port before sending an HTTP request and processing the response.
ESP32 Library Index
- ESP32 WiFi Library
- ESP32 HTTPClient Library
- ESP32 WiFiClientSecure Library
- ESP32 WebServer Library
- ESP32 WiFiClient Library
- Connection
- Send Data
- Receive Data
- Config
- Status
- Which ESP32 Boards are Recommended for Learners
- How to Copy Codes from AvantMaker.com
- What is SPIFFS and how to upload files to it?
- What is LIttleFS and how to upload files to it?
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