问Linux UDP客户端，如何实现？

EN

#include <stdio.h>
#include <sys/socket.h>
#include <netdb.h>

int main () {
    char buf[4] = { 0xff, 0xff, 0xff, 0xff };
    struct addrinfo adr, *res;
    adr.ai_family = AF_INET;
    adr.ai_socktype = SOCK_DGRAM;
    getaddrinfo ("192.168.1.1", NULL, &adr, &res);
    int sd = socket (res->ai_family, res->ai_socktype, res->ai_protocol);
    if (sendto (sd, buf, sizeof (buf), MSG_OOB, res->ai_addr, res->ai_addrlen) < 0)
          perror ("ERROR sendto"); //I have added an if tag and an error message posiblility
    return 0;
}