From Forum Nokia Wiki

This example shows how to convert an IP address in dotted string format to an integer array.

PRECONDITIONS

A buffer containing the IP address in dotted format

Add following lines in .cpp file.

TBuf<100> yourIPContainingBuffer;
yourIPContainingBuffer.Append(_L("123.456.789.000"));
TInt length = yourIPContainingBuffer.Length();
RArray<TInt> yourDottedArray;
TInt startPos = 0;
TInt endPos = 0;
 
for(TInt index = 0; index<length+1; index++)
  {
  if(endPos!=length && TChar(yourIPContainingBuffer[index])!=TChar('.'))
     {
     endPos++;
     }
  else
     {
     // You should copy everything starting from startPos to endPos into yourDottedArray
     TInt temp = 0;
     TInt tempLength = endPos-startPos;
     TBuf<4> tempBuf;
     tempBuf = yourIPContainingBuffer.Mid(startPos, tempLength);
     TLex tempLex(tempBuf);
     if(tempLex.Val(temp) == KErrNone)
	 {
	 // We got our first val, lets put it on the yourDottedArray
	 yourDottedArray.AppendL(temp);
	 }
     endPos++; //To accomodate the dot we got
     startPos = endPos;
     }
  }

While using the array, after each index, keep appending the '.' in the calling code to convert it back into a dotted IP address format buffer/string.

POSTCONDITIONS

An integer array containing the IP address

Added by - Mayank on 19/05/2009

A Simpler and Faster Solution

A much simpler and faster solution to the problem mentioned above exists using the TInetAddr class. Below are two functions that convert an Ipv4 ip address in string representation to interger and vice versa:

TUint32 InetAddrV4_StringToIntegerL(const TDesC& aIpDes)
  {
   TInetAddr addr;
   User::LeaveIfError(addr.Input(aIpDes)); //leave if ip address is malformed
   return addr.Address(); //returns the intger representation
  }
 
void InetAddrV4_IntegerToString(TUint32 aIpAddr,TDes& aIpDes)
  {
   TInetAddr addr;
   addr.SetAddress(aIpAddr);   //set the ip address of TInetAddr
   addr.Output(aIpDes);        //convert the ip address to string representation
  }

Following code can be used to access the individual components of the Ipv4 address

TUint32 address=InetAddrV4_StringToIntegerL(_L("192.168.0.1"));
	TUint32 bytea= (address&0xff000000)>>24; //returns  192
	TUint32 byteb= (address&0xff0000)>>16; //returns  168
	TUint32 bytec= (address&0xff00)>>8; //returns  0
	TUint32 byted= (address&0xff); //returns  1

Added by Vaibhav Jain- 21 May 2009