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

The solution that I settled on was:

#include 
// ...
bool Config::validateIpAddress(const string &ipAddress)
{
    struct sockaddr_in sa;
    int result = inet_pton(AF_INET, ipAddress.c_str(), &(sa.sin_addr));
    return result != 0;
}

This works for most cases that were mentioned in other answers. It doesn't recognize IP addresses with octal or hex formatting, but that's acceptable for my application.