/* tcpserver.c
 *
 * TCP Server
 * note: 'echo "hello" | nc localhost 8080' to send messages to the server
 *
 *
 */

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

int main(int argc, char **argv)
{
    if (argc != 2)
    {
        fprintf(stderr, "usage: %s <port>\n", argv[0]);
        exit(1);
    }

    int server_sockfd, ret;

    if ((server_sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
    {
        perror("socket");
        close(server_sockfd);
        exit(-1);
    }

    /* allow fast reuse of ports */
    int reuse_true = 1;
    setsockopt(server_sockfd, SOL_SOCKET, SO_REUSEADDR, &reuse_true,
               sizeof(reuse_true));

    struct sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(atoi(argv[1]));
    addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(server_sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
    {
        perror("bind");
        exit(-1);
    }

    if (listen(server_sockfd, 0) == -1)
    {
        perror("listen");
        exit(-1);
    }

    struct sockaddr_in remote_addr;
    unsigned int socklen = sizeof(remote_addr);

    while (1)
    {
        int sockfd;
        sockfd = accept(server_sockfd, (struct sockaddr *) &remote_addr, &socklen);
        if (sockfd == -1)
        {
            perror("socket");
            close(sockfd);
            exit(-1);
        }

        char buf[255] = { 0 };
        if ((ret = recv(sockfd, buf, sizeof(buf), 0)) < 0)
        {
            perror("recv");
            exit(-1);
        }

        printf("%s", buf);
        shutdown(sockfd, SHUT_RDWR);
        close(sockfd);
    }

    shutdown(server_sockfd, SHUT_RDWR);
    close(server_sockfd);
}