How do you validate that a string is a valid IPv4 address in C++?

Question

I don\'t need to validate that the IP address is reachable or anything like that. I just want to validate that the string is in dotted-quad (xxx.xxx.xxx.xxx) IPv4 format, w

Answer 1

You can write your own function like this:

bool isValidIPv4(const char *IPAddress)
{
   unsigned char a,b,c,d;
   return sscanf(IPAddress,"%d.%d.%d.%d", &a, &b, &c, &d) == 4;
}

sscanf() and sprintf() are very useful in some situation. :))