Use regular expressions:
Code:
string Input = "Yatta yolla http://www.rapidshare.com/yango/yema.html yorka http://www.rapidshare.com yinto";
string Expression = "http://www\\.rapidshare\\.com.*? ";
System.Text.RegularExpressions.Regex Regex = new System.Text.RegularExpressions.Regex(Expression);
foreach(System.Text.RegularExpressions.Match Match in Regex.Matches(Input))
{
string FullAddress = Input.Substring(Match.Index, Match.Length);
}
The above code is relatively simple, may be improved. Like it assumes the address ends with a blankspace.