C++ TCP Examples

client.cpp

#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>

#include <iostream>
using namespace std;
// Defining Port, Note that port is same on which server is listening and on
// which we want to connect
#define PORT 9000
/*
 * This method will create server socket, bind and listen to incomming requests
 * Parameters
 * @argc: Number of command line args passed
 * @*argv[]: Character array containing command line args
 */
int main(int argc, char const *argv[]) {
  int sock = 0, input;
  struct sockaddr_in serverAddress;  // structure for storing address char *msg
                                     // = "Hello Server. Its Ninja here";
  char buffer[2048] = {0};
  if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
    cout << ("Failed To Create Socket\n");
    return -1;
  }
  // configuring Address
  serverAddress.sin_family = AF_INET;
  serverAddress.sin_port = htons(PORT);
  // now we will Convert IPv4 and IPv6 addresses from text to binary form
  if (inet_pton(AF_INET, "127.0.0.1", &serverAddress.sin_addr) <= 0) {
    cout << ("Invalid address, its not supported");
    return -1;
  }
  if (connect(sock, (struct sockaddr *)&serverAddress, sizeof(serverAddress)) <
      0) {
    cout << ("\nConnection with server is Failed \n");
    return -1;
  }
  cout << "Message sent to server from client";
    char *msg = "Hello Ninja. Its Client here";
  send(sock, msg, strlen(msg), 0);
  // now we will read message
  input = read(sock, buffer, 2048);
  // printing Buffer
  cout << ("%s\n", buffer);
  return 0;
}

server.cpp

#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>

#include <iostream>

using namespace std;  // Defining Port

#define PORT 9000
/*
* This method will create server socket, bind and listen to incomming
requests
* Parameters
* @argc: Number of command line args passed
* @*argv[]: Character array containing command line args */
int main(int argc, char const *argv[]) {
  int serverFileDescriptor, SOCKET, input;
  struct sockaddr_in address;
  int opt = 1;
  int addrlen = sizeof(address);
  char buffer[1024] = {0};
  char *msg = "Hello Ninja. Its Server here";
  // Creating socket file descriptor
  if ((serverFileDescriptor = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
    perror("Failed to create socket");
    exit(EXIT_FAILURE);
  }
  // No we will attach socket to the port 9000
  if (setsockopt(serverFileDescriptor, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT,
                 &opt, sizeof(opt))) {
    perror("Failed to set socket options");
    exit(EXIT_FAILURE);
  }
  // Configuring Address
  address.sin_family = AF_INET;
  address.sin_addr.s_addr = INADDR_ANY;
  address.sin_port = htons(PORT);
  // Forcefully attaching socket to the port 8080
  if (bind(serverFileDescriptor, (struct sockaddr *)&address, sizeof(address)) <
      0) {
    perror("Server BINDING Failed");
    exit(EXIT_FAILURE);
  }
  // Now we will listen to incoming requests
  if (listen(serverFileDescriptor, 3) < 0) {
    perror("Failed when listening...");

    exit(EXIT_FAILURE);
  }
  if ((SOCKET = accept(serverFileDescriptor, (struct sockaddr *)&address,
                       (socklen_t *)&addrlen)) < 0) {
    perror("Failed to accept incoming request");
    exit(EXIT_FAILURE);
  }
  input = read(SOCKET, buffer, 1024);
  cout << buffer << endl;
  cout << "Sending Message to clients...";
  send(SOCKET, msg, strlen(msg), 0);
  return 0;
}

tcp_client.cpp

// https://simpledevcode.wordpress.com/2016/06/16/client-server-chat-in-c-using-sockets/

#include <arpa/inet.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <unistd.h>

#include <fstream>
#include <iostream>
#include <string>
using namespace std;
// Client side
int main(int argc, char *argv[]) {
  // we need 2 things: ip address and port number, in that order
  if (argc != 3) {
    cerr << "Usage: ip_address port" << endl;
    exit(0);
  }  // grab the IP address and port number
  char *serverIp = argv[1];
  int port = atoi(argv[2]);
  // create a message buffer
  char msg[1500];
  // setup a socket and connection tools
  struct hostent *host = gethostbyname(serverIp);
  sockaddr_in sendSockAddr;
  bzero((char *)&sendSockAddr, sizeof(sendSockAddr));
  sendSockAddr.sin_family = AF_INET;
  sendSockAddr.sin_addr.s_addr =
      inet_addr(inet_ntoa(*(struct in_addr *)*host->h_addr_list));
  sendSockAddr.sin_port = htons(port);
  int clientSd = socket(AF_INET, SOCK_STREAM, 0);
  // try to connect...
  int status =
      connect(clientSd, (sockaddr *)&sendSockAddr, sizeof(sendSockAddr));
  if (status < 0) {
    cout << "Error connecting to socket!" << endl;
    return EXIT_FAILURE;
  }
  cout << "Connected to the server!" << endl;
  int bytesRead, bytesWritten = 0;
  struct timeval start1, end1;
  gettimeofday(&start1, NULL);
  while (1) {
    cout << ">";
    string data;
    getline(cin, data);
    memset(&msg, 0, sizeof(msg));  // clear the buffer
    strcpy(msg, data.c_str());
    if (data == "exit") {
      send(clientSd, (char *)&msg, strlen(msg), 0);
      break;
    }
    bytesWritten += send(clientSd, (char *)&msg, strlen(msg), 0);
    cout << "Awaiting server response..." << endl;
    memset(&msg, 0, sizeof(msg));  // clear the buffer
    bytesRead += recv(clientSd, (char *)&msg, sizeof(msg), 0);
    if (!strcmp(msg, "exit")) {
      cout << "Server has quit the session" << endl;
      break;
    }
    cout << "Server: " << msg << endl;
  }
  gettimeofday(&end1, NULL);
  close(clientSd);
  cout << "********Session********" << endl;
  cout << "Bytes written: " << bytesWritten << " Bytes read: " << bytesRead
       << endl;
  cout << "Elapsed time: " << (end1.tv_sec - start1.tv_sec) << " secs" << endl;
  cout << "Connection closed" << endl;
  return 0;
}

tcp_server.cpp

// https://simpledevcode.wordpress.com/2016/06/16/client-server-chat-in-c-using-sockets/

#include <arpa/inet.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <unistd.h>

#include <fstream>
#include <iostream>
#include <string>
using namespace std;
// Server side
int main(int argc, char *argv[]) {
  // for the server, we only need to specify a port number
  if (argc != 2) {
    cerr << "Usage: port" << endl;
    exit(0);
  }
  // grab the port number
  int port = atoi(argv[1]);
  // buffer to send and receive messages with
  char msg[1500];

  // setup a socket and connection tools
  sockaddr_in servAddr;
  bzero((char *)&servAddr, sizeof(servAddr));
  servAddr.sin_family = AF_INET;
  servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  servAddr.sin_port = htons(port);

  // open stream oriented socket with internet address
  // also keep track of the socket descriptor
  int serverSd = socket(AF_INET, SOCK_STREAM, 0);
  if (serverSd < 0) {
    cerr << "Error establishing the server socket" << endl;
    exit(0);
  }
  // bind the socket to its local address
  int bindStatus =
      bind(serverSd, (struct sockaddr *)&servAddr, sizeof(servAddr));
  if (bindStatus < 0) {
    cerr << "Error binding socket to local address" << endl;
    exit(0);
  }
  cout << "Waiting for a client to connect..." << endl;
  // listen for up to 5 requests at a time
  listen(serverSd, 5);
  // receive a request from client using accept
  // we need a new address to connect with the client
  sockaddr_in newSockAddr;
  socklen_t newSockAddrSize = sizeof(newSockAddr);
  // accept, create a new socket descriptor to
  // handle the new connection with client
  int newSd = accept(serverSd, (sockaddr *)&newSockAddr, &newSockAddrSize);
  if (newSd < 0) {
    cerr << "Error accepting request from client!" << endl;
    exit(1);
  }
  cout << "Connected with client!" << endl;
  // lets keep track of the session time
  struct timeval start1, end1;
  gettimeofday(&start1, NULL);
  // also keep track of the amount of data sent as well
  int bytesRead, bytesWritten = 0;
  while (1) {
    // receive a message from the client (listen)
    cout << "Awaiting client response..." << endl;
    memset(&msg, 0, sizeof(msg));  // clear the buffer
    bytesRead += recv(newSd, (char *)&msg, sizeof(msg), 0);
    if (!strcmp(msg, "exit")) {
      cout << "Client has quit the session" << endl;
      break;
    }
    cout << "Client: " << msg << endl;
    cout << ">";
    string data;
    getline(cin, data);
    memset(&msg, 0, sizeof(msg));  // clear the buffer
    strcpy(msg, data.c_str());
    if (data == "exit") {
      // send to the client that server has closed the connection
      send(newSd, (char *)&msg, strlen(msg), 0);
      break;
    }
    // send the message to client
    bytesWritten += send(newSd, (char *)&msg, strlen(msg), 0);
  }
  // we need to close the socket descriptors after we're all done
  gettimeofday(&end1, NULL);
  close(newSd);
  close(serverSd);
  cout << "********Session********" << endl;
  cout << "Bytes written: " << bytesWritten << " Bytes read: " << bytesRead
       << endl;
  cout << "Elapsed time: " << (end1.tv_sec - start1.tv_sec) << " secs" << endl;
  cout << "Connection closed..." << endl;
  return 0;
}