C语言udp服务器端实现自定义ip和端口并且间隔显示丢包率的代码

以下是C语言UDP服务器端实现自定义IP和端口并且间隔显示丢包率的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <errno.h>

#define BUF_SIZE 1024

int main(int argc, char *argv[]) {
    if (argc != 4) {
        printf("Usage: %s [ip] [port] [interval]\n", argv[0]);
        exit(1);
    }

    struct sockaddr_in serv_addr, clnt_addr;
    socklen_t clnt_addr_len = sizeof(clnt_addr);
    char buf[BUF_SIZE];

    // Create UDP socket
    int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock_fd < 0) {
        perror("socket creation failed");
        exit(1);
    }

    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_addr.sin_port = htons(atoi(argv[2]));

    // Bind socket to address
    if (bind(sock_fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        perror("bind failed");
        exit(1);
    }

    unsigned long interval = strtoul(argv[3], NULL, 0);
    unsigned long pkts_sent = 0;
    unsigned long pkts_recv = 0;

    struct timeval timeout = {
        .tv_sec = (long)interval,
        .tv_usec = 0
    };
    if (setsockopt(sock_fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(struct timeval)) < 0) {
        perror("setsockopt failed");
        exit(1);
    }

    while (1) {
        if (recvfrom(sock_fd, buf, BUF_SIZE, 0, (struct sockaddr *)&clnt_addr, &clnt_addr_len) >= 0) {
            pkts_recv++;
        } else if (errno != EAGAIN && errno != EWOULDBLOCK) {
            perror("recvfrom failed");
            exit(1);
        }

        pkts_sent++;
        double loss_rate = (double)(pkts_sent - pkts_recv) / pkts_sent * 100.0;
        printf("Sent %lu packets, Received %lu packets, Loss rate: %0.2f%%\n", pkts_sent, pkts_recv, loss_rate);

        sleep(interval);
    }

    close(sock_fd);

    return 0;
}

以上代码实现了一个UDP服务器端，代码中使用了`socket()`函数创建socket，`bind()`函数将socket绑定到指定的IP和端口，`recvfrom()`函数接收数据并计算丢包率。同时，也支持指定间隔时间并在指定间隔时间内显示丢包率。