function main() {
    const regex4ipv4 = /^(((25[0-5])|(2[0-4]\d)|(1\d{2})|(\d{1,2}))\.){3}((25[0-5])|(2[0-4]\d)|(1\d{2})|(\d{1,2}))$/;
    const regex4ipv6 = /^(([0-9a-f]{1,4}):){7}([0-9a-f]{1,4})$/;
    for (let i = 1; i < inputLines.length; i++) {
        const str = inputLines[i];
        if (regex4ipv4.test(str)) {
            console.info('IPv4');
        } else if (regex4ipv6.test(str)) {
            console.info('IPv6');
        } else {
            console.info('Neither');
        }
    }
}

<?php
    $input = stream_get_contents($_fp);
    $lines = preg_split('/\R/', $input, -1, PREG_SPLIT_NO_EMPTY);
    array_shift($lines);
    $ipv4_pattern = '/^(([01]?[0-9]{0,2}|2[0-5]?[0-5]?)\.){3}([01]?[0-9]{0,2}|2[0-5]?[0-5]?)$/';
    $ipv6_pattern = '/^(([a-fA-F0-9]{1,4}):){7}[a-fA-F0-9]{1,4}$/';
    foreach($lines as $line) {
        $result = 'Neither';
        if (preg_match($ipv4_pattern, $line)) {
            $result = 'IPv4';
        } elseif (preg_match($ipv6_pattern, $line)) {
            $result = 'IPv6';
        }
        
        echo $result . PHP_EOL;
    }

while(<>){
    chomp;
    next if $. == 1;
    if (/^(\d+)\.(\d+)\.(\d+)\.(\d+)$/){
    ($1 < 256 && $2 < 256 && $3 < 256 && $4 < 256) ? print "IPv4\n" : print "Neither\n";
        
    } elsif ( /^([a-f\d]{1,4}):([a-f\d]{1,4}):([a-f\d]{1,4}):([a-f\d]{1,4}):([a-f\d]{1,4}):([a-f\d]{1,4}):([a-f\d]{1,4}):([a-f\d]{1,4})$/ ){
        print "IPv6\n";
    } else {
        print "Neither\n";
    }