PHP ip2long Function

last modified April 4, 2025

The PHP ip2long function converts a human-readable IP address to a long integer. This is useful for IP storage and range comparisons.

Basic Definition

ip2long converts an IPv4 address from string to long integer. The integer can be used for efficient storage and IP address manipulation.

Syntax: ip2long(string $ip): int|false. Returns the long integer or false on failure. Works only with IPv4 addresses, not IPv6.

Basic IP Conversion

This example demonstrates the basic conversion of an IP address to long.

basic_conversion.php

<?php

declare(strict_types=1);

$ip = "192.168.1.1";
$long_ip = ip2long($ip);

echo "IP: $ip\n";
echo "Long: $long_ip\n";

The output shows the string IP and its long integer representation. This conversion is useful for compact storage in databases.

IP Address Validation

This example shows how to validate an IP address using ip2long.

ip_validation.php

<?php

declare(strict_types=1);

function isValidIp($ip) {
    return ip2long($ip) !== false;
}

$test_ip = "256.0.0.1"; // Invalid IP
echo isValidIp($test_ip) ? "Valid" : "Invalid";

The function returns false for invalid IP addresses. Note that some invalid IPs might still return a long value due to PHP's conversion.

IP Range Checking

This demonstrates checking if an IP falls within a specific range.

ip_range_check.php

<?php

declare(strict_types=1);

$ip = "192.168.1.100";
$start = "192.168.1.1";
$end = "192.168.1.254";

$long_ip = ip2long($ip);
$long_start = ip2long($start);
$long_end = ip2long($end);

if ($long_ip >= $long_start && $long_ip <= $long_end) {
    echo "$ip is in range $start - $end";
} else {
    echo "$ip is NOT in range";
}

Converting IPs to longs allows numeric comparison of IP ranges. This is more efficient than string-based range checking.

IP Storage in Database

This example shows storing IP addresses as integers in a database.

ip_database_storage.php

<?php

declare(strict_types=1);

$ip = "10.0.0.5";
$long_ip = ip2long($ip);

// Using PDO for database connection
$pdo = new PDO('mysql:host=localhost;dbname=test', 'user', 'pass');
$stmt = $pdo->prepare("INSERT INTO logs (ip_address) VALUES (?)");
$stmt->execute([$long_ip]);

echo "Stored IP: $ip as $long_ip";

Storing IPs as integers saves space and allows efficient range queries. Remember to convert back using long2ip when retrieving.

Network Address Calculation

This example calculates network addresses using bitwise operations.

network_calculation.php

<?php

declare(strict_types=1);

$ip = "192.168.1.100";
$mask = "255.255.255.0";

$long_ip = ip2long($ip);
$long_mask = ip2long($mask);

$network = $long_ip & $long_mask;
echo "Network address: " . long2ip($network);

This calculates the network address by ANDing the IP with the netmask. Network calculations are essential for subnetting and routing.

Best Practices

Validation: Always validate IPs before conversion
Storage: Consider unsigned integers for storage
IPv6: Use other functions for IPv6 addresses
Endianness: Be aware of platform byte order differences
Negative values: Handle potential negative integers

Source

PHP ip2long Documentation

This tutorial covered the PHP ip2long function with practical examples for IP address manipulation, validation, and storage.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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