long2ip

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

    long2ip — Converts a long integer address into a string in (IPv4) Internet standard dotted format

    Description

    long2ip(int $ip): string

    The function long2ip() generates an Internet address in dotted format (i.e.: aaa.bbb.ccc.ddd) from the long integer representation.

    Parameters

    ip

    A proper address representation in long integer.

    Return Values

    Returns the Internet IP address as a string, or false on failure.

    Changelog

    Version Description
    7.1.0 The parameter type of ip has been changed from string to int.

    Notes

    Note:

    On 32-bit architectures, casting integer representations of IP addresses from string to int will not give correct results for numbers which exceed PHP_INT_MAX.

    See Also

    • ip2long() - Converts a string containing an (IPv4) Internet Protocol dotted address into a long integer

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    User Contributed Notes 6 notes

    up
    5
    steve at computurn dot com
    6 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);
    }
    up
    9
    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;
    }
    }
    ?>
    up
    2
    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
    up
    1
    Rolf
    3 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.
    up
    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));
    }
    ?>
    up
    -2
    Anonymous
    13 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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