training_repo/select/client_tcp_select.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/select.h>

#define BUFFER_SIZE 256

void error(const char *msg) {
        perror(msg);
            exit(1);
}
int main()
{
    int client_fd;
    struct sockaddr_in server;
    fd_set readfds;
    char buffer[BUFFER_SIZE];
    // Create a TCP socket
    client_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (client_fd < 0)
    {
        error("Error opening socket.");
    }
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = inet_addr("127.0.0.1"); // Change this to server's IP address
    server.sin_port = htons(5000);
     // Connect to the server
    if (connect(client_fd, (struct sockaddr *)&server, sizeof(server)) < 0)
    {
            error("Connection error");
    }
    printf("Connected to the server.\n");
    while (1)
    {
        // Clear the socket set and add client socket to it
        FD_ZERO(&readfds);
        FD_SET(client_fd, &readfds);
        FD_SET(STDIN_FILENO, &readfds); // Add standard input to readfds
        // Wait for an activity on one of the sockets
        int activity = select(client_fd + 1, &readfds, NULL, NULL, NULL);
        if (activity < 0)
        {
            error("Select error");
        }
        //If data is received from the server
        if (FD_ISSET(client_fd, &readfds))
        {
            int valread = read(client_fd, buffer, sizeof(buffer));
            if (valread > 0)
            {
                buffer[valread] = '\0'; // Null-terminate the received string
                printf("Broadcast from server: %s\n", buffer);
            }
        }
        // If input is available from the console
        if (FD_ISSET(STDIN_FILENO, &readfds))
        {
            fgets(buffer, BUFFER_SIZE, stdin);
            buffer[strcspn(buffer, "\n")] = 0; // Remove trailing newline character
            send(client_fd, buffer, strlen(buffer), 0);
        }
    }
        close(client_fd);
        return 0;
}