linux|linux c 网络编程（用域名获取IP地址或者用IP获取域名网络地址转换成整型主机字符顺序与网络字节顺序的转换） linux|c编程

用域名获取IP地址或者用IP获取域名

#include #include #include int main(int argc,char **aggv) { struct hostent *host; char hostname[]="www.163.com"; char hostname2[]="www.baidu.com"; struct in_addr in; struct sockaddr_in addr_in; int h_errno; char addr[]="202.108.249.216"; if((host=gethostbyname(hostname))!=NULL) { memcpy(&addr_in.sin_addr.s_addr,host->h_addr,4); in.s_addr=addr_in.sin_addr.s_addr; printf("Domain name : %s \n",hostname); printf("IP length is: %d \n",host->h_length); printf("Type : %d \n",host->h_addrtype); printf("IP : %s \n",inet_ntoa(in)); }if(((host=gethostbyaddr(addr,sizeof(addr),AF_INET)))!=(struct hostnet *)NULL) { memcpy(&addr_in.sin_addr.s_addr,host->h_addr,4); in.s_addr=addr_in.sin_addr.s_addr; printf("\n---------------------\n"); printf("Domain name : %s \n",hostname); printf("IP length is: %d \n",host->h_length); printf("Type : %d \n",host->h_addrtype); printf("IP : %s \n",inet_ntoa(in)); } return 0; }

#include #include #include int main() { int i ; for(i=0; i<6; i++) printf("%d%s \n",i,hstrerror(i)); //捕获错误编号char cp[]="192.168.0.84"; printf("%ld\n",inet_addr(cp));

//将网络地址转换成整型

struct in_addr ip; ip.s_addr=16885952; printf("%s\n",inet_ntoa(ip));

//将整型转换成网络地址

long local; int port; local=123456; port=1024; printf("net: %d\n",htonl(local)); //主机字符顺序与网络字节顺序的转换 printf("net: %d\n",htonl(port)); printf("local: %d\n",ntohl(htonl(local))); printf("local: %d\n",ntohl(htonl(port))); return 0; }

【linux|linux c 网络编程（用域名获取IP地址或者用IP获取域名网络地址转换成整型主机字符顺序与网络字节顺序的转换）】