struct hostent结构体
结构体定义:
struct hostent { char *h_name; //正式主机名 char **h_aliases; //主机别名 int h_addrtype; //主机IP地址类型 int h_length; //主机IP地址字节长度 char **h_addr_list; //主机的IP地址列表 }
#include <stdio.h> #include <netdb.h> #include <sys/socket.h> int main(int argc, char *argv[]) { char *ptr, **pptr; struct hostent *hptr; char str[32] = {0}; ptr = argv[1]; if((hptr = gethostbyname(ptr)) == NULL) { printf("gethostbyname error: %s\n", ptr); return 0; } printf("official hostname:%s\n", hptr->h_name); //主机规范名 for(pptr = hptr->h_aliases; *pptr != NULL; pptr++) //将主机别名打印出来 printf("alias: %s\n", *pptr); switch(hptr->h_addrtype) //根据地址类型,将地址打印出来 { case AF_INET: case AF_INET6: pptr = hptr->h_addr_list; for(; *pptr != NULL; pptr++) //将得到的所有地址打印出来 { printf("address: %s\n", inet_ntop(hptr->h_addrtype, *pptr, str, sizeof(str))); //inet_ntop: 将网络字节序的二进制转换为文本字符串的格式 printf("first address: %s\n", inet_ntop(hptr->h_addrtype, hptr->h_addr, str, sizeof(str))); } break; default: printf("unkown address type\n"); break; } return 0; }
运行结果:
official hostname:www.a.shifen.com
alias: www.baidu.com
address: 115.239.211.112
first address: 115.239.211.112
address: 115.239.210.27
first address: 115.239.211.112