long2ip

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

long2ip Konvertiert eine Long-Integer-Adresse in einen String, der das (IPv4) Internet-Standard-Punktformat enthält ("Dotted-Format")

Beschreibung

long2ip(int $ip): string|false

Die Funktion long2ip() erzeugt eine IP-Adresse im Punktformat (also: www.xxx.yyy.zzz) anhand der Long-Integer-Adresse.

Parameter-Liste

ip

Eine korrekte Adressdarstellung als Long Integer.

Rückgabewerte

Gibt die IP-Adresse als String zurück. Bei einem Fehler wird false zurückgegeben.

Changelog

Version Beschreibung
7.1.0 Der Parametertyp von ip wurde von string zu int geändert.

Anmerkungen

Hinweis:

Auf 32-bit-Architekturen ergibt die Umwandlung von Integer-Darstellungen von IP-Adresssen von string nach int für Zahlen, die PHP_INT_MAX überschreiten, keine richtigen Ergebnisse.

Siehe auch

  • ip2long() - Konvertiert eine gemäß IPv4-Protokoll angegebene IP-Adresse vom Punkt-Format in ein Long Integer

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User Contributed Notes 8 notes

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10
Gabriel Malca
18 years ago
If the function doesn't exist:

<?
    if (!function_exists("long2ip")) {
        function long2ip($long) {
            // Valid range: 0.0.0.0 -> 255.255.255.255
            if ($long < 0 || $long > 4294967295) return false;
            $ip = "";
            for ($i=3;$i>=0;$i--) {
                $ip .= (int)($long / pow(256,$i));
                $long -= (int)($long / pow(256,$i))*pow(256,$i);
                if ($i>0) $ip .= ".";
            }
            return $ip;
        }
    }
?>
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1
steve at computurn dot com
5 years ago
For a 32bit safe long2ip, which can accept string or signed integer input, try:

  function safelong2ip($long) {
    $binStr = sprintf("%032s", decbin((float)$long));
    if (strlen($binStr) != 32) {
      throw new Exception("Invalid IPv4 subnet!");
    }

    $ipArr = [];
    for ($i = 0; $i < 4; ++$i) {
      $ipArr[] = bindec(substr($binStr, $i*8, 8));
    }

    return implode('.', $ipArr);
  }
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0
Rolf
2 years ago
an Anonymous wrote several years ago that you should cast the parameter to float to make sure that you get the right result on 32-bit machines. That probably never worked.

But the idea is on a good track: to convert a bitstring into an ip, use

$ip = long2ip((int)bindec($bits));

This works on 32- and 64-bit machines.
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0
klawd at kamundo dot de
12 years ago
Use these two functions to convert from and to numbers compatible to MySQLs INET_ATON and INET_NTOA
<?php
   
function convertIpToString($ip)
    {
       
$long = 4294967295 - ($ip - 1);
        return
long2ip(-$long);
    }
    function
convertIpToLong($ip)
    {
        return
sprintf("%u", ip2long($ip));
    }
?>
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0
Anonymous
12 years ago
If you're running a 32 bit machine you can get wrong IPs. To prevent from this just cast to float e.g.

<?php
long2Ip32bit
($ip){
   return
long2ip((float)$ip);
}
?>
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0
Tom Crosley
21 years ago
I wanted to be able to pass an IP address in a URL always as an unsigned int.  I then converted it back as shown below:

$ip_addr = "192.168.100.25";  // example IP address that converts to neg #

$s32int = ip2long($ip_addr);

$us32str = sprintf("%u",$s32int);               // convert to unsigned string

// display orig IP address, signed 32 bit version, unsigned 32 bit ver,
// finally converted back to IP addr

printf("%s ,%d, %s, %s", $ip_addr, $s32int, $us32str,
         long2ip(-(4294967296-$us32str)));

// tested on Linux/Apache PHP 4.1.2
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-6
flobee
19 years ago
when importing ip-ranges to a mysql database using an INT(10) field - NOTE: that you will get problems when using intval() function!

copied from "cleong" : 02-Oct-2001 02:21
intval() handles overflow differently depending on the type of the argument.
<?php
// intval('10000000000') = 2147483647
// intval(1e10) = 1410065408
?>
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-12
php dot net at davidstockton dot com
15 years ago
Beware when processing values that are invalid, you may get values that are different based on the OS.  For instance:

$ip = long2ip(pow(2,32)+1024);

On windows you get 255.255.255.255.  On linux it's 0.0.4.0.

So it seems it would be important to make sure the long you're converting is in the correct range.
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