初次写这些难免有不足之处，还望大家指出缺点
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
int main(argc, argv)
int argc;
char **argv;
{
struct hostent *ip;
unsigned long hostname;
if (argc != 2)
{
printf("Need to specify an IP address.\n");
exit(1);
}
if ((hostname = inet_addr(argv[1])) == -1)
{
printf("Could not find %s\n", argv[1]);
exit(1);
}
if ((ip = gethostbyaddr((char *)&hostname, sizeof(long), AF_INET)) != NULL)
printf("%s is %s\n", argv[1], ip->h_name);
else
printf("Could not resolve %s\n", argv[1]);
return 0;
}
