public static string InvertHost(string host)
{
if (HostUtils.IsNumeric(host))
{
return(host);
}
else
{
int n = host.Length;
char[] res = new char[n];
int a = 0;
while (a < n)
{
int c = a;
while (c < n && host[c] != '.')
{
c++;
}
int d = n - c;
while (a < c)
{
res[d++] = host[a++];
}
res[d++] = '.';
a = c + 1;
}
return(new string(res));
}
}
public static string InvertHost(string url)
{
int a = PrefixLength(url);
int b = HostLength(url, a);
return(url.Substring(0, a)
+ HostUtils.InvertHost(url.Substring(a, b))
+ url.Substring(a + b));
}
public static string DomainOf(string url)
{
return(HostUtils.DomainOf(UrlUtils.HostOf(url)));
}