Question

我想在Mac OS X上编译UDP客户端的示例代码，但出现以下错误：

client.c:91:9: error: use of undeclared identifier 'MSG_CONFIRM'
        MSG_CONFIRM, (const struct sockaddr *) &servaddr,
        ^

我用Google搜索了几个小时的错误，但无法找到与此问题相关的任何内容。有谁知道问题是什么以及如何解决？

UDP客户端的代码在

之下

// Client side implementation of UDP client-server model
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netdb.h>

#define PORT     8080
#define MAXLINE 1024

// Driver code
int main() {
    int sockfd;
    char buffer[MAXLINE];
    char *hello = "Hello from client";
    struct sockaddr_in     servaddr;

    // Creating socket file descriptor
    if ( (sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ) {
        perror("socket creation failed");
        exit(EXIT_FAILURE);
    }

    memset(&servaddr, 0, sizeof(servaddr));

    // Filling server information
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(PORT);
    servaddr.sin_addr.s_addr = INADDR_ANY;

    int n, len;

    sendto(sockfd, (const char *)hello, strlen(hello),
        MSG_CONFIRM, (const struct sockaddr *) &servaddr,
            sizeof(servaddr));
    printf("Hello message sent.\n");

    while (1)
    {
        n = recvfrom(sockfd, (char *)buffer, MAXLINE,
                MSG_WAITALL, (struct sockaddr *) &servaddr,
                &len);
        buffer[n] = '\0';
        printf("Server : %s\n", buffer);
    }

    close(sockfd);
    return 0;
}

Answer 1

我的朋友建议我将MSG_CONFIRM定义为0。他说搜索它的用途。您还要对其进行研究。

#define MSG_CONFIRM 0

OS X上的UDP客户端

1 个答案: