inet_ntoa 的一个小问题

一个简单点的阻塞式tcp服务器如下所示:

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#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
                                                                                                                  
 
int main(int argc, char**argv)
{
    int listenfd,connfd,n, ret;
    struct sockaddr_in servaddr, cliaddr;
    socklen_t clilen;
    pid_t     childpid;
    char mesg[1000], *peeraddr;
 
    listenfd = socket(AF_INET, SOCK_STREAM, 0);
    if (listenfd < 0) {
        printf("create socket error\n");
        return -1;
    }
    printf("create socket success\n");
 
    memset(&servaddr, 0, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(6789);
 
    ret = bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
    if (ret == -1) {
        printf("bind error\n");
        return -1;
    }
    printf("bind success\n");
 
    ret = listen(listenfd, 1024);
    if (ret == -1) {
        printf("listen error\n");
        return -1;
    }
 
    printf("listening...\n");
 
    for (;;) {
        clilen = sizeof(cliaddr);
        connfd = accept(listenfd, (struct sockaddr *)&cliaddr, &clilen);
 
        printf("Accept request from %s\n", inet_ntoa(cliaddr.sin_addr));
 
        n = read(connfd, mesg, 1000);
        if (n < 0) {
            printf("read error!\n");
        }
 
        printf("Received:%s\n", mesg);
 
        close(connfd);
    }
}

  编译期间没有遇到问题。运行的时候程序在47行收到了segment fault错误。用man手册查看inet_ntoa,调用方式如下:

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char *inet_ntoa(struct in_addr in);

  cliaddr的类型定义是:

 struct sockaddr_in { /* in netinet/in.h */

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<em id="__mceDel">       sa_family_t       sin_family;
       in_port_t         sin_port;
       struct in_addr    sin_addr;  
       unsigned char     sin_zero[sizeof(struct sockaddr) - sizeof(sa_family_t) - sizeof(in_port_t), sizeof(struct in_addr)];
};
</em>

  乍一看,没什么问题啊,怎么会出现段错误呢?

 

     捣腾了半天,才发现是缺少了inet_ntoa所在的头文件 arpa/inet.h,包含该头文件即可。好坑。

 

inet_ntoa 的一个小问题,布布扣,bubuko.com

inet_ntoa 的一个小问题

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