public static void ValidateIPV4Address(string IPV4address)
{
if (string.IsNullOrEmpty(IPV4address))
{
Console.WriteLine("Entered string is NULL!");
}
else
{
IPV4address = IPV4address.Trim();
if (string.IsNullOrEmpty(IPV4address))
{
Console.WriteLine("Entered string is NULL!");
}
else
{
if (IPV4address.Any(c => char.IsDigit(c)))
{
DotIndices dotIndices = CountDots(IPV4address);
if (dotIndices.GetFirstString() != null && dotIndices.GetSecondString() != null &&
dotIndices.GetThirdString() != null && dotIndices.GetFourthString() != null)
{
dotIndices.SetFirstValidation(ValidateStringForIPRange(dotIndices.GetFirstString()));
dotIndices.SetSecondValidation(ValidateStringForIPRange(dotIndices.GetSecondString()));
dotIndices.SetThirdValidation(ValidateStringForIPRange(dotIndices.GetThirdString()));
dotIndices.SetFourthValidation(ValidateStringForIPRange(dotIndices.GetFourthString()));
if (dotIndices.GetFirstValidation() && dotIndices.GetSecondValidation() &&
dotIndices.GetThirdValidation() && dotIndices.GetFourthValidated())
{
Console.WriteLine("-----------------------------------");
Console.WriteLine("Entered IPV4 address is valid!");
}
else
{
Console.WriteLine("-----------------------------------");
Console.WriteLine("Entered IPV4 address is not valid!");
}
}
else
{
Console.WriteLine("Entered IP address is invalid (Format)!");
}
}
else
{
Console.WriteLine("IP address should have numbers!");
}
}
}
}
public static DotIndices CountDots(string IPaddress)
{
DotIndices dotIndices = new DotIndices();
int dotCount = 0;
char[] charArray = IPaddress.ToCharArray();
if (charArray.Length > 15)
{
Console.WriteLine("Maximum length of IP address can be only 15");
}
else
{
for (int i = 0; i < IPaddress.Length; i++)
{
if (charArray[i] == '.')
{
if (dotCount == 3)
{
Console.WriteLine("Invalid IPV4 address - Only 3 dots can be present in the IP address");
return(dotIndices);
}
dotCount++;
if (dotIndices.GetFirstIndex() == 0)
{
dotIndices.SetFirstIndex(i);
dotIndices.SetFirstString(
IPaddress.Substring(0, i));
}
else
{
if (dotIndices.GetSecondIndex() == 0)
{
int firstIndex = dotIndices.GetFirstIndex();
dotIndices.SetSecondIndex(i);
dotIndices.SetSecondString(
IPaddress.Substring(
firstIndex + 1,
i - (firstIndex + 1)));
}
else
{
int secIndex = dotIndices.GetSecondIndex();
dotIndices.SetThirdIndex(i);
dotIndices.SetThirdString(
IPaddress.Substring(
secIndex + 1,
i - (secIndex + 1)));
}
}
}
}
if (dotCount < 3)
{
Console.WriteLine("Entered IP address is not valid!");
return(dotIndices);
}
else
{
dotIndices.SetFourthString(
IPaddress.Substring(dotIndices.GetThirdIndex() + 1,
IPaddress.Length - (dotIndices.GetThirdIndex() + 1)));
}
}
return(dotIndices);
}
