Changes to external ip

Using Arduino Networking, Protocols, and Devices
10

Well thats really the part i dont get, i can not get the external ip (thanks) so so far ive got:

//ARDUINO 1.0+ ONLY
//ARDUINO 1.0+ ONLY
#include <Ethernet.h>
#include <SPI.h>

////////////////////////////////////////////////////////////////////////
//CONFIGURE
////////////////////////////////////////////////////////////////////////
byte server[] = { 192,168,0,31 }; //ip Address of the server you will connect to

//The location to go to on the server
//make sure to keep HTTP/1.0 at the end, this is telling it what type of file it is
String location = "/externalip.php/ HTTP/1.0";

// if need to change the MAC address (Very Rare)
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
////////////////////////////////////////////////////////////////////////

EthernetClient client;

char inString[32]; // string for incoming serial data
int stringPos = 0; // string index counter
boolean startRead = false; // is reading?

void setup(){
  Ethernet.begin(mac);
  Serial.begin(9600);
}

void loop(){
  String pageValue = connectAndRead(); //connect to the server and read the output

  Serial.println(pageValue); //print out the findings.

  delay(5000); //wait 5 seconds before connecting again
}

String connectAndRead(){
  //connect to the server

  Serial.println("connecting...");

  //port 80 is typical of a www page
  if (client.connect(server, 80)) {
    Serial.println("connected");
    client.print("GET ");
    client.println(location);
    client.println();

    //Connected - Read the page
    return readPage(); //go and read the output

  }else{
    return "connection failed";
  }

}

String readPage(){
  //read the page, and capture & return everything between '<' and '>'

  stringPos = 0;
  memset( &inString, 0, 32 ); //clear inString memory

  while(true){

    if (client.available()) {
      char c = client.read();

      if (c == '<' ) { //'<' is our begining character
        startRead = true; //Ready to start reading the part 
      }else if(startRead){

        if(c != '>'){ //'>' is our ending character
          inString[stringPos] = c;
          stringPos ++;
        }else{
          //got what we need here! We can disconnect now
          startRead = false;
          client.stop();
          client.flush();
          Serial.println("disconnecting.");
          return inString;

        }

      }
    }

  }

}

I setup a webserver localy on that ip for now which is printing the internal ip but shows alls working, so as of now i get a simple ip address.

So i think what i need to do is then save that numer as a string?
Then wait (thats the easy bit :slight_smile: )
Then change the name of the now old ip sting to "old"
Check again and call it "new"
Check old against new
If old is the same as new then...
If not start again
But i have no idea how to get the read data and save it as a string?

Thanks again for your time