ip2long

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

&reftitle.description; ``int``false```ip2long` `string` `ip`

The function `ip2long` generates a long integer representation of IPv4 Internet network address from its Internet standard format (dotted string) representation.

`ip2long` will also work with non-complete IP addresses. Read &url.ip2long.tech; for more info.

&reftitle.parameters;

`ip`

- A standard format address.

&reftitle.returnvalues;

Returns the long integer or &false; if `ip` is invalid.

&reftitle.examples;

### `ip2long` Example

    <?php
    $ip = gethostbyname('www.example.com');
    $out = "The following URLs are equivalent:<br />\n";
    $out .= 'http://www.example.com/, http://' . $ip . '/, and http://' . sprintf("%u", ip2long($ip)) . "/<br />\n";
    echo $out;
    ?>

### Displaying an IP address

This second example shows how to print a converted address with the `printf` function:

    <?php
    $ip   = gethostbyname('www.example.com');
    $long = ip2long($ip);

    if ($long == -1 || $long === FALSE) {
        echo 'Invalid IP, please try again';
    } else {
        echo $ip   . "\n";            // 192.0.34.166
        echo $long . "\n";            // 3221234342 (-1073732954 on 32-bit systems, due to integer overflow)
        printf("%u\n", ip2long($ip)); // 3221234342
    }
    ?>

&reftitle.notes;

Because PHP's `int` type is signed, and many IP addresses will result in negative integers on 32-bit architectures, you need to use the "%u" formatter of `sprintf` or `printf` to get the string representation of the unsigned IP address.

`ip2long` will return `-1` for the IP `255.255.255.255` on 32-bit systems due to the integer value overflowing.

&reftitle.seealso;

- `long2ip`
- `sprintf`