Experiment 3 socket programming in tcp client and tcp server udp server

 Server.c

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <arpa/inet.h>

int main(){

  char *ip = "127.0.0.1";

  int port = 5566;

  int server_sock, client_sock;

  struct sockaddr_in server_addr, client_addr;

  socklen_t addr_size;

  char buffer[1024];

  int n;

  server_sock = socket(AF_INET, SOCK_STREAM, 0);

  if (server_sock < 0){

    perror("[-]Socket error");

    exit(1);

  }

  printf("[+]TCP server socket created.\n");

  memset(&server_addr, '\0', sizeof(server_addr));

  server_addr.sin_family = AF_INET;

  server_addr.sin_port = port;

  server_addr.sin_addr.s_addr = inet_addr(ip);

  n = bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr));

  if (n < 0){

    perror("[-]Bind error");

    exit(1);

  }

  printf("[+]Bind to the port number: %d\n", port);

  listen(server_sock, 5);

  printf("Listening...\n");

  while(1){

    addr_size = sizeof(client_addr);

    client_sock = accept(server_sock, (struct sockaddr*)&client_addr, &addr_size);

    printf("[+]Client connected.\n");

    bzero(buffer, 1024);

    recv(client_sock, buffer, sizeof(buffer), 0);

    printf("Client: %s\n", buffer);

    bzero(buffer, 1024);

    strcpy(buffer, "HI, THIS IS SERVER. HAVE A NICE DAY!!!");

    printf("Server: %s\n", buffer);

    send(client_sock, buffer, strlen(buffer), 0);

    close(client_sock);

    printf("[+]Client disconnected.\n\n");

  }

  return 0;

}             

---------------------------------------------------------------------client.c

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <arpa/inet.h>

int main(){

  char *ip = "127.0.0.1";

  int port = 5566;

  int sock;

  struct sockaddr_in addr;

  socklen_t addr_size;

  char buffer[1024];

  int n;

  sock = socket(AF_INET, SOCK_STREAM, 0);

  if (sock < 0){

    perror("[-]Socket error");

    exit(1);

  }

  printf("[+]TCP server socket created.\n");

  memset(&addr, '\0', sizeof(addr));

  addr.sin_family = AF_INET;

  addr.sin_port = port;

  addr.sin_addr.s_addr = inet_addr(ip);

  connect(sock, (struct sockaddr*)&addr, sizeof(addr));

  printf("Connected to the server.\n");

  bzero(buffer, 1024);

  strcpy(buffer, "HELLO, THIS IS CLIENT.");

  printf("Client: %s\n", buffer);

  send(sock, buffer, strlen(buffer), 0);

  bzero(buffer, 1024);

  recv(sock, buffer, sizeof(buffer), 0);

  printf("Server: %s\n", buffer);

  close(sock);

  printf("Disconnected from the server.\n");

  return 0;

}

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Outputs