Accessing IP Address with NSHost

Question

I am trying to get the IP Address using NSHost. With the NSHost object I can use the addresses method to access an array of objects one of which is the IP Address. I fear though that the IP Address may change position in the array from one machine to the other. Is there a way to access this information in a universal way?

There was an attempt to answer this question in a previous post, but as you can see it falls short.

IP Address? - Cocoa

Here is my code:

+(NSString *) ipAddress {
    NSHost * h = [[[NSHost currentHost] addresses] objectAtIndex:1];
    return h ;  
}

Answer 1

I wanted to update my original answer on getting an external ip.

There is not much change but I wanted to show how to get and parse the HTML with use NSXMLDocument and Xquary

This also gives a small illustration of how you can parse HTML by getting the nodes. Which in my opinion is more straight forward. Although NSXMLDocument is initially for XML it will parse the HTML DOM tree

    NSString *externalIP;

    ///--DYNDNS.ORG  URL

    NSURL *iPURL = [NSURL URLWithString:@"http://www.dyndns.org/cgi-bin/check_ip.cgi"];
    if (iPURL) {

        NSError *err_p = nil;


        //--use NSXMLDocument to get the url:(*Requests NSXMLNode to preserve whitespace characters (such as tabs and carriage returns) in the XML source that are not part of node content*)
    NSXMLDocument * xmlDoc = [[NSXMLDocument alloc] initWithContentsOfURL:iPURL
                                                                  options:(NSXMLNodePreserveWhitespace|
                                                                           NSXMLNodePreserveCDATA)
                                                                    error:&err_p];

    if (xmlDoc == nil) {

        //-- That did not work so lets see if we can change the malformed XML into valid XML during processing of the document.
        xmlDoc = [[NSXMLDocument alloc] initWithContentsOfURL:iPURL
                                                      options:NSXMLDocumentTidyXML
                                                        error:&err_p];

    }


    if (!err_p) {
 NSError * error;
        //-- We will use XQuary to get the text from the child node. Dyndns.org page is very simple. So we just need to get the Body text.

    NSString *xpathQueryTR =  @"//body/text()";
        //-- we get the first node's string value. We use string value to in effect cast to NSString.
        //We the seperate the string into components using a space. and obtain the last object in the returned array.
        //--This gives us the IP string without the "Current IP Address:" string.
    externalIP = [[[[[xmlDoc nodesForXPath:xpathQueryTR error:&error]objectAtIndex:0] stringValue]componentsSeparatedByString:@" "]lastObject];

    if (!error) {

    NSLog(@"%@",externalIP);

    }else {
        NSLog(@"Oops... g %ld, %@",
              (long)[error code],
              [error localizedDescription]);
    }

    }else {
        NSLog(@"Oops... g %ld, %@",
              (long)[err_p code],
              [err_p localizedDescription]);
    }
}