在未连接的Socket上发送UDP数据报的方法

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include "my_inet.h"
#include <stdio.h>
#include <errno.h>
#include <arpa/inet.h>
#include <unistd.h>
int main()
{
        int i;
        struct sockaddr_in dest;
        dest.sin_family = MY_PF_INET;
        dest.sin_port = htons(16000);
        dest.sin_addr.s_addr = 0x013010AC;  //目的地址是172.16.48.1(网络字节序)
        //创建UDP数据报服务的socket。
        int fd = socket( MY_PF_INET, SOCK_DGRAM, MY_IPPROTO_UDP );
        if( fd < 0 ){
            perror("socket: ");
            return -1;
        }
        int bwrite = sendto( fd, "abcdefg", 7, 0, (struct sockaddr *)&dest, sizeof(dest) );
        if( bwrite == -1 ){
            perror("send: ");
            close(fd);
            return -1;
        }
        printf("sendto: %d\n", bwrite);
        close( fd );
        return 0;
                }