testing the cymru netcat access

cymru-lookup.php

<?php

/* test host list */
$hostlist = array(
    '96.4.1.22',
    '207.191.191.90',
    '8.8.8.8'
);

/* do the lookup */
function lookup(array $hosts = array()) {
    /* open the socket */
    $sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)
        or die("Unable to create socket\n");

    /* connect to cymru */
    socket_connect($sock, 'whois.cymru.com', 43)
        or die("Unable to connect to whois.cymru.com\n");

    /* generate request */
    $request = sprintf("begin\nverbose\n%s\nend\n", join("\n", $hosts));

    /* write the request */
    socket_write($sock, $request, strlen($request))
        or die("Unable to write request to socket\n");

    /* array of labels */
    $labels = array(
        0 => 'as',
        1 => 'ip',
        2 => 'prefix',
        3 => 'cc',
        4 => 'registry',
        5 => 'allocated',
        6 => 'name'
    );

    /* init output */
    $output = array();

    /* loop through the results */
    while (true) {
        /* read line from socket */
        $line = @socket_read($sock, 2048, PHP_NORMAL_READ);
        /* nothing left to read */
        if (!strlen($line)) break;
        /* break line on pipes */
        $parts = explode('|', $line, 7);
        /* skip lines that don't contain all the fields */
        if (count($parts) !== 7) continue;
        /* temp array */
        $temps = array();
        /* parse the line and assign labels */
        foreach ($labels as $idx => $name) {
            /* build array */
            $temps[$name] = trim($parts[$idx]);
        }
        /* append to output */
        $output[$temps['prefix']] = $temps;
    }

    /* close socket */
    socket_close($sock);

    /* return json */
    return json_encode($output, JSON_PRETTY_PRINT);
}

/* call lookup and print results */
printf("%s\n", lookup($hostlist));