getname.c

打印指定目录下

#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
char *host, **names,**addrs;
struct hostent *hostinfo;
if (argc == 1)
{
	char myname[256];
	gethostname(myname,255);
	host = myname;
}
else 
	host =argv[1];
hostinfo = gethostbyname(host);
if(!hostinfo)
{
	fprintf(stderr, "cannot get info for host:%s\n",host);
	exit(1);
}
printf("results for host %s:\n",host);
printf("Name: %s\n",hostinfo->h_name);
printf("Aliases:");
names = hostinfo->h_aliases;
while(*names)
{
	printf(" %s",*names);
	names++;
}
printf("\n");
if(hostinfo->h_addrtype != AF_INET)
{
	fprintf(stderr, "not an IP host!\n");
	exit(1);
}
addrs = hostinfo->h_addr_list;
while(*addrs)
{
	printf(" %s",inet_ntoa(*(struct in_addr *)*addrs));
	addrs++;
}
printf("\n");
exit(0);
}