#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>

#define PORT 8080

int main(void)
{
        int master_sock;
        int sock;
        struct sockaddr_in address;
        int opt = 1;
        int addrlen = sizeof(address);
        char str[4096] = {0};

        // allocating socket
        if (!(master_sock = socket(AF_INET, SOCK_STREAM, 0))) {
                perror("\nERROR: SOCKET ALLOCATION FAILED\n");
                return 1;
        }

        // attaching socket to the port 8080
        if (setsockopt(master_sock, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
                perror("\nERROR: ATTACHING SOCKET TO THE PORT 8080 FAILED\n");
                return 1;
        }

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

        // bind
        if (bind(master_sock, (struct sockaddr*) &address, sizeof(address)) < 0) {
                perror("\nERROR: BIND FAILED\n");
                return 1;
        }

        // try to specify maximum of 3 pending connections for the master socket
        if (listen(master_sock, 3) < 0) {
                perror("\nERROR: LISTEN\n");
                return 1;
        }

        printf("listening on port 8080...\n");
        fflush(stdin);

        if ((sock = accept(master_sock, (struct sockaddr*) &address, (socklen_t*) &addrlen)) < 0) {
                perror("\nERROR: ACCEPT FAILED\n");
                return 1;
        }

        printf("connection accepted!\n");
        fflush(stdout);

        close(0);
        dup(sock);
        while (1) {
                scanf("%s", str);
                printf("%s", str);
                fflush(stdout);
        }

        return(0);
}