To receive data over a socket in C++, you need to perform the following steps:

1. Create a buffer to store the received data. The buffer can be a character array or a string.

   TEXT/X-C++SRC

   1#include <iostream>
   2const int bufferSize = 1024;
   3char buffer[bufferSize];

2. Use the recv() function to receive data. Pass the socket descriptor, the buffer, the size of the buffer, any additional flags (usually 0), and any necessary error handling.

   TEXT/X-C++SRC

   1int bytesReceived = recv(sockfd, buffer, bufferSize, 0);
   2if (bytesReceived == -1) {
   3  std::cout << "Error receiving data" << std::endl;
   4  return 1;
   5}

3. Check the value of bytesReceived to determine if data was successfully received. If bytesReceived is 0, it means the connection has been closed by the other side.

   TEXT/X-C++SRC

   1if (bytesReceived == 0) {
   2  std::cout << "Connection closed" << std::endl;
   3}

4. Process the received data stored in the buffer as needed.

   TEXT/X-C++SRC

   1std::cout << "Received data: " << buffer << std::endl;

5. Repeat the receive process as necessary to receive additional data.

   TEXT/X-C++SRC

   1bytesReceived = recv(sockfd, buffer, bufferSize, 0);
   2// Process additional received data

Here's an example code that demonstrates how to receive data over a socket in C++:

1#include <iostream>
2#include <sys/socket.h>
3
4int main() {
5  // Create a socket
6  int sockfd = socket(AF_INET, SOCK_STREAM, 0);
7  if (sockfd == -1) {
8    std::cout << "Failed to create socket" << std::endl;
9    return 1;
10  }
11
12  // ... Set up server address and connect to server ...
13
14  // Receive data
15  const int bufferSize = 1024;
16  char buffer[bufferSize];
17  int bytesReceived = recv(sockfd, buffer, bufferSize, 0);
18  if (bytesReceived == -1) {
19    std::cout << "Error receiving data" << std::endl;
20    return 1;
21  }
22
23  if (bytesReceived == 0) {
24    std::cout << "Connection closed" << std::endl;
25  }
26
27  std::cout << "Received data: " << buffer << std::endl;
28
29  // Close the socket
30  close(sockfd);
31
32  return 0;
33}