kliens:

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


int main() {
    //man socket
    int my_socket = socket(AF_INET, SOCK_STREAM, 0);
    //man 7 ip sockaddr_in
    /* struct sockaddr_in {
               sa_family_t    sin_family;
               in_port_t      sin_port;
               struct in_addr sin_addr;
           };

           struct in_addr {
               uint32_t       s_addr;
           };*/

    struct sockaddr_in server_infos;
    server_infos.sin_family = AF_INET;
    server_infos.sin_port = htons(35000);
    server_infos.sin_addr.s_addr = inet_addr("127.0.0.1");

    connect(my_socket, (struct sockaddr *)&server_infos, sizeof(struct sockaddr));
    //man send, man recv
    char input[1000];
    recv(my_socket, input, 999, 0);
    printf("Uzenet a szervertől: %s", input);

    while(1) {
        printf("Mit akarsz kuldeni:\n");
        fgets(input, 999, stdin);
        send(my_socket, input, strlen(input), 0);
        recv(my_socket, input, 999, 0);
        printf("Valasz: %s", input);
    }
    return 0;

}

server:

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

int main() {
    int my_socket, cli1_socket, cli2_socket;

    struct sockaddr_in server_infos;
    struct sockaddr_in client_infos;
    socklen_t sock_size = sizeof(struct sockaddr_in);

    my_socket = socket(AF_INET, SOCK_STREAM, 0);

    server_infos.sin_family = AF_INET;
    server_infos.sin_port = htons(35000);
    server_infos.sin_addr.s_addr = INADDR_ANY;
    //man bind
    bind(my_socket, (struct sockaddr *)&server_infos, sock_size);
    //man listen
    listen(my_socket, 2);
    //man 2 accept
    cli1_socket = accept(my_socket, (struct sockaddr *)&client_infos, &sock_size);
    cli2_socket = accept(my_socket, (struct sockaddr *)&client_infos, &sock_size);

    const char *msg_cli1 = "Hello klines1\n";
    const char *msg_cli2 = "Hello klines2\n";
    send(cli1_socket, msg_cli1, strlen(msg_cli1), 0);
    send(cli2_socket, msg_cli2, strlen(msg_cli2), 0);

    char cli1_msg[1000];
    char cli2_msg[1000];

    while(1) {
        recv(cli1_socket, cli1_msg, 999, 0);
        recv(cli2_socket, cli2_msg, 999, 0);
    }

    return 0;
    }