A little problem with Inet_ntoa

A simple point of blocking TCP server is as follows:

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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);     } }

No issues were encountered during compilation. At run time the program received a segment fault error on line 47. Use the man manual to view Inet_ntoa, which is called as follows:

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1	char *inet_ntoa(structin_addr in);

The type definition for CLIADDR is:

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 charsin_zero[sizeof(struct sockaddr) - sizeof(sa_family_t) - sizeof(in_port_t), sizeof(struct in_addr)]; }; </em>

At first glance, no problem ah, how can there be a paragraph error?

Churn a half-day, only to find that the Inet_ntoa is missing the header file Arpa/inet.h, including the header file can be. Good pit.