DNS to IP

[Irish_GUI]

Hi, can someone please give me an example of how to translate a domain name eg. www.codeproject.com into its IP address. i have this working for network machine names but not for domain names. preferably into CString or unsigned long format. Thanks

[monrobot13]

You could try looking at gethostbyname. - Aaron

[Irish_GUI]

Aaron i cannot get that to work.. GetHostAddress("http://www.coderproject.com"); unsigned long DialogClass::GetHostAddress(LPCSTR host) { struct hostent *phe; char *p; phe = gethostbyname(host); p = *phe->h_addr_list; // Crash here return *((unsigned long*)p); } any ideas ?

[monrobot13]

Try changing:

p = *phe->h_addr_list;

to

p = *phe->h_addr;

- Aaron

[RobJones]

Didn't compile it so it may have type-o's...

// Name resolution
struct hostent *hp;
unsigned int addr;
struct sockaddr_in name_ip;

// Make sure that strDns is not already an IP Address.
if(inet_addr(strDns) == INADDR_NONE)
hp = gethostbyname(strDns);
else
{
addr = inet_addr(strDns);
hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET);
}

if(hp == NULL)
{
// Handle the error here..
}

name_ip.sin_addr.s_addr = *((unsigned long*)hp->h_addr);
name_ip.sin_family = AF_INET;
name_ip.sin_port = htons(iPort);

// Assign strSocketIP to the IP address...
CString strSocketIP = inet_ntoa(name_ip.sin_addr);

Rob Whoever said nothing's impossible never tried slamming a revolving door!

[Irish_GUI]

Rob, thanks for that but in flow of execution strDns = "www.codeproject.com"; hp = gethostbyname(strDns); executes fine name_ip.sin_addr.s_addr = *((unsigned long*)hp->h_addr); // crash occurs name_ip.sin_family = AF_INET; name_ip.sin_port = htons(iPort); any ideas?

[Irish_GUI]

i am using winsock 1.1 if that might be a problem in the struct hostent *hp; i only have the following members: hp->h_addr_list hp->h_addrtype hp->h_aliases hp->h_length hp->h_name i do not have a hp->h_addr member

[RobJones]

I'm not 100% sure, I have only had experence in WinSock2.. you may lookup gethostbyname in google or msdn and see if you can find any Winsock 1.1 examples.. you could snoop through the articles here too.. I'm sure it can't be too hard. If you still have problems let me konw and I'll see what I can find. Rob Whoever said nothing's impossible never tried slamming a revolving door!

[RobJones]

I just did a google search and found this right off the bat... The macro h_addr is defined to be h_addr_list[0] for compatibility with older software. Rob Whoever said nothing's impossible never tried slamming a revolving door!