gethostbynamel

    (PHP 4, PHP 5, PHP 7, PHP 8)

    gethostbynamel — Devuelve la lista de direcciones IPv4 correspondientes a un host

    Descripción

    gethostbynamel(string $hostname): array|false

    Devuelve la lista de direcciones IPv4 correspondientes al host hostname.

    Parámetros

    hostname

    El nombre del host.

    Valores devueltos

    Devuelve un array de direcciones IPv4, o false si hostname no pudo ser resuelto.

    Ejemplos

    Ejemplo #1 Ejemplo con gethostbynamel()

    <?php
    $hosts     = gethostbynamel('www.example.com');
    print_r($hosts);
    ?>

    El ejemplo anterior mostrará :

    Array
(
    [0] => 192.0.34.166
)

    Ver también

    • gethostbyname() - Obtener la dirección IPv4 que corresponde a un nombre de host de Internet dado
    • gethostbyaddr() - Devuelve el nombre de host correspondiente a una IP
    • checkdnsrr() - Resolución DNS de una dirección IP
    • getmxrr() - Devuelve los registros MX de un host
    • La página del manual named(8)

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    User Contributed Notes 4 notes

    up
    10
    ab at null dot ixo dot ca
    9 years ago
    If using gethostbyname against the name of the localhost is always giving you 127.0.0.1 but you want the DNS address instead, just put a dot at the end of the name. E.g.,

    $foo = gethostbynamel("myhost.example.com");
    print_r($foo);

    ...is giving you this:
    Array
    (
    [0] => 127.0.0.1
    )

    Then put a dot at the end of the name:

    $foo = gethostbynamel("myhost.example.com.");
    print_r($foo);

    ...and now you get something like:
    Array
    (
    [0] => 172.217.1.99
    )
    up
    -3
    info at methfessel-computers.de
    18 years ago
    The solution is simpel. Just add a . (point) to the end of the URL for correct name resolving.

    Without this point PHP thinks it's a subdomain of your local domain and so returns the "local-IP".
    up
    -4
    Skyld at o2 dot co dot uk
    20 years ago
    Obviously, in some cases, not all IPs are likely to be useful while checking a hostname. Sometimes also, not all IPs will work. This code will check for the first WORKING IP from the list. Or at least it should - I haven't had time to test it yet.
    Needs domain parameter, and port and max IPs to check are optional.
    If port is not set, it will check HTTP port 80, and if max IPs to check is not set, it will only check the first 10 IPs from the list.
    Hope it helps someone.

    <?php
    function checkhostlist($domain, $port = 80, $maxipstocheck = 10) {
    ?     $hosts = gethostbynamel($domain);
    for (    $chk=0;$chk<$maxipstocheck;$chk++) {
    if (isset(    $hosts[$chk])) {
    $th = fsockopen($domain, $port);
    if (    $th) {
    fclose($th);
    return     $hosts[$chk];
    break;
    }
    }
    }
    }
    ?>
    up
    -4
    webdev at concraption dot com
    19 years ago
    In PHP 5.0.4, gethostbynamel returns an empty string instead of false if the lookup fails. A simple workaround for this error is to use is_array() in an IF block:

    <?
    $hosts = gethostbynamel($hostname);
    if (is_array($hosts)) {
    echo "Host ".$hostname." resolves to:<br><br>";
    foreach ($hosts as $ip) {
    echo "IP: ".$ip."<br>";
    }
    } else {
    echo "Host ".$hostname." is not tied to any IP.";
    }
    ?>
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