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

int main() {
    int sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock < 0) exit(1);

    struct sockaddr_in addr;
    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(9000);
    addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(sock, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
        close(sock);
        exit(1);
    }

    char buf[1024];
    struct sockaddr_in client;
    socklen_t len = sizeof(client);

    while (1) {
        int n = recvfrom(sock, buf, sizeof(buf)-1, 0, (struct sockaddr*)&client, &len);
        if (n > 0) {
            buf[n] = '\0';
            printf("%s\n", buf);
        }
    }

    close(sock);
    return 0;
}