【C语言】查询域名IP

/*
 ============================================================================
 Name        : inettest.c
 Author      : Moshiyou<momo1a@qq.com>
 Version     :
 Copyright   : Your copyright notice
 Description : Hello World in C, Ansi-style
 ============================================================================
 */

#include <csapp.h>

int main(int argc,char **argv) {
	struct addrinfo *p,*listp,hints;
	char buf[MAXLINE];
	int rc,flags;

	if(argc != 2){
		fprintf(stderr,"usage:%s <domain name>\n",argv[0]);
		exit(0);
	}

	/* get a list of addrinfo record */

	memset(&hints,0,sizeof(struct addrinfo));
	hints.ai_family = AF_INET;
	hints.ai_socktype = SOCK_STREAM;

	if((rc = getaddrinfo(argv[1],NULL,&hints,&listp)) != 0){
		fprintf(stderr,"getaddrinfo error: %s",gai_strerror(rc));
		exit(0);
	}

	/* walk the list and display each IP address */

	flags = NI_NUMERICHOST;  /* display address string instead domain name*/
	for(p = listp ; p ; p = p->ai_next){
		getnameinfo(p->ai_addr,p->ai_addrlen,buf,MAXLINE,NULL,0,flags);
		printf("%s\n",buf);
	}

	/* clean up*/
	freeaddrinfo(listp);
	exit(0);
}