training_repo/TCP_CLIENT_SERVER/server.c

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

#define PORT 8081
#define BUFFER_SIZE 1024

int main() {
    int server_fd, new_socket;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[BUFFER_SIZE] = {0};

    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("Socket failed");
        exit(EXIT_FAILURE);
    }

    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("Bind failed");
        exit(EXIT_FAILURE);
        }

    if (listen(server_fd, 3) < 0) {
        perror("Listen");
  exit(EXIT_FAILURE);
    }

    printf("Server listening on port %d\n", PORT);

    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
        perror("Accept");
        exit(EXIT_FAILURE);
    }

    while (1) {
        memset(buffer, 0, BUFFER_SIZE);
        int read_size = read(new_socket, buffer, BUFFER_SIZE);
       if (read_size == 0) {
            printf("Client disconnected\n");
            break;
        }
        printf("Received: %s", buffer);

        send(new_socket, buffer, read_size, 0);
        printf("Echoed back: %s", buffer);
    }

    close(new_socket);
    close(server_fd);
    return 0;
}