linux udp 广播出

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

int main() {
    int sockfd;
    struct sockaddr_in addr;
    char buffer[] = "Hello, this is a broadcast message!";

    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(8888);
    addr.sin_addr.s_addr = inet_addr("255.255.255.255");

    if (sendto(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
        perror("sendto");
        exit(1);
    }

    close(sockfd);
    return 0;
}

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

int main() {
    int sockfd;
    struct sockaddr_in addr;
    socklen_t addrlen = sizeof(addr);
    char buffer[1024];

    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(8888);
    addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(sockfd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
        perror("bind");
        exit(1);
    }

    while (1) {
        int n = recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)&addr, &addrlen);
        if (n == -1) {
            perror("recvfrom");
            break;
        }
        buffer[n] = '\0';
        printf("Received: %s\n", buffer);
    }

    close(sockfd);
    return 0;
}