Get localhost IP

Started by zackriggle December 07, 2002 08:38 AM

5 comments, last by zackriggle 22 years, 2 months ago

Author

130

December 07, 2002 08:38 AM

How do I determine: A.) If a user is connected to the internet (this is from their own computer) B.) Get the localhost IP if they are connected Please help and thank you.

Fruny

1,658

December 07, 2002 08:52 AM

A.) I know there was a WinNT API function, but I can't remember ...
B.) open a socket and call getsockname on it.

Edit - trying to fix that #[~{ signature.

"Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." — Brian W. Kernighan

Themonkster

159

December 07, 2002 09:02 AM

what are you using for this?
winsock has a local ip method.

My F1 Blog http://www.willtheyeverovertake.com F1 News Blog

DarkHamster

180

December 08, 2002 12:51 PM

I'm trying to do the same thing (using linux though, not winsock), and I'm wondering why the following code:

int main(){char ac[80];gethostname(ac,sizeof(ac));cout << "Host name is " << ac << ndl;struct hostent *phe = gethostbyname(ac);if(phe==0)   return 1;for(int i=0; phe->h_addr_list != 0; i++){struct in_addr addr;memcpy(&addr, phe->h_addr_list, sizeof(struct inaddr));<br>cout << "Address " << i << ": " << inet_ntoa(addr) << endl;<br>}<br><br>return 0;<br>}<br>  </pre>   </i> <br><br>wouold &#111;nly print out<br><br>Host name is localhost.localdomain<br>Address 0: 127.0.0.1<br><br>I know I have another IP besides my loopback (I'm &#111;n the internet, with a 56k), so where is it?    <br><br><HTML><BR><BR>"There is no dark side of the moon really,<BR>As a matter of fact, its all dark."<br><br><SPAN CLASS=editedby>[edited by - DarkHamster &#111;n December 8, 2002 3:40:34 PM]</SPAN>

"There is no dark side of the moon really,
As a matter of fact, its all dark."

Dean Harding

546

December 08, 2002 03:26 PM

The best way, I''m afraid, is to connect to another host and ask it. The reason is that you might be behind a NAT or a firewall which is not directly connected to your PC but is changing your address as your traffic passes through it.

There''s plenty of websites out there which, given the right URL, will simply return the IP address the request came from. Have a look at how those DynDNS clients work...

If I had my way, I''d have all of you shot!

codeka.com - Just click it.

DarkHamster

180

December 08, 2002 03:37 PM

How would I look up my local IP on a LAN, not the internet?

"There is no dark side of the moon really,
As a matter of fact, its all dark."

"There is no dark side of the moon really,
As a matter of fact, its all dark."

Dean Harding

546

December 09, 2002 02:32 AM

On a LAN is easier. You can use gethostbyname, and pass in localhost. This will return a list of all the IP addresses that your computer has. You can then just ignore the 127.0.0.1 address it''ll return and use the other(s).

Remember, though, that you can still have firewalls and NATs within a LAN. For a home setup, though, that''s going to be unlikely.

If I had my way, I''d have all of you shot!

codeka.com - Just click it.

Get localhost IP

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Get localhost IP

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines