Task: Parse an IP Address


C++: #include <boost/asio/ip/address.hpp>
#include <cstdint>
#include <iostream>
#include <iomanip>
#include <limits>
#include <string>

using boost::asio::ip::address;
using boost::asio::ip::address_v4;
using boost::asio::ip::address_v6;
using boost::asio::ip::make_address;
using boost::asio::ip::make_address_v4;
using boost::asio::ip::make_address_v6;

template<typename uint>
bool parse_int(const std::string& str, int base, uint& n) {
    try {
        size_t pos = 0;
        unsigned long u = stoul(str, &pos, base);
        if (pos != str.length() || u > std::numeric_limits<uint>::max())
            return false;
        n = static_cast<uint>(u);
        return true;
    } catch (const std::exception& ex) {
        return false;
    }
}












void parse_ip_address_and_port(const std::string& input, address& addr, uint16_t& port) {
    size_t pos = input.rfind(':');
    if (pos != std::string::npos && pos > 1 && pos + 1 < input.length()
        && parse_int(input.substr(pos + 1), 10, port) && port > 0) {
        if (input[0] == '[' && input[pos - 1] == ']') {
            
            addr = make_address_v6(input.substr(1, pos - 2));
            return;
        } else {
            try {
                
                addr = make_address_v4(input.substr(0, pos));
                return;
            } catch (const std::exception& ex) {
                
            }
        }
    }
    port = 0;
    addr = make_address(input);
}

void print_address_and_port(const address& addr, uint16_t port) {
    std::cout << std::hex << std::uppercase << std::setfill('0');
    if (addr.is_v4()) {
        address_v4 addr4 = addr.to_v4();
        std::cout << "address family: IPv4\n";
        std::cout << "address number: " << std::setw(8) << addr4.to_uint() << '\n';
    } else if (addr.is_v6()) {
        address_v6 addr6 = addr.to_v6();
        address_v6::bytes_type bytes(addr6.to_bytes());
        std::cout << "address family: IPv6\n";
        std::cout << "address number: ";
        for (unsigned char byte : bytes)
            std::cout << std::setw(2) << static_cast<unsigned int>(byte);
        std::cout << '\n';
    }
    if (port != 0)
        std::cout << "port: " << std::dec << port << '\n';
    else
        std::cout << "port not specified\n";
}

void test(const std::string& input) {
    std::cout << "input: " << input << '\n';
    try {
        address addr;
        uint16_t port = 0;
        parse_ip_address_and_port(input, addr, port);
        print_address_and_port(addr, port);
    } catch (const std::exception& ex) {
        std::cout << "parsing failed\n";
    }
    std::cout << '\n';
}

int main(int argc, char** argv) {
    test("127.0.0.1");
    test("127.0.0.1:80");
    test("::ffff:127.0.0.1");
    test("::1");
    test("[::1]:80");
    test("1::80");
    test("2605:2700:0:3::4713:93e3");
    test("[2605:2700:0:3::4713:93e3]:80");
    return 0;
}






Python: from ipaddress import ip_address
from urllib.parse import urlparse

tests = [
    "127.0.0.1",
    "127.0.0.1:80",
    "::1",
    "[::1]:80",
    "::192.168.0.1",
    "2605:2700:0:3::4713:93e3",
    "[2605:2700:0:3::4713:93e3]:80" ]

def parse_ip_port(netloc):
    try:
        ip = ip_address(netloc)
        port = None
    except ValueError:
        parsed = urlparse('//{}'.format(netloc))
        ip = ip_address(parsed.hostname)
        port = parsed.port
    return ip, port

for address in tests:
    ip, port = parse_ip_port(address)
    hex_ip = {4:'{:08X}', 6:'{:032X}'}[ip.version].format(int(ip))
    print("{:39s}  {:>32s}  IPv{}  port={}".format(
        str(ip), hex_ip, ip.version, port ))