PHP net_get_interfaces Function

last modified April 4, 2025

The PHP net_get_interfaces function retrieves network interface information. It provides details about all network interfaces on the system.

Basic Definition

net_get_interfaces returns an associative array of network interfaces. Each interface contains details like IP addresses and MAC.

Syntax: net_get_interfaces(): array|false. Returns array on success, false on failure. Available since PHP 7.3.

Basic Interface Listing

This example shows how to get and display all network interfaces.

basic_interfaces.php

<?php

declare(strict_types=1);

$interfaces = net_get_interfaces();

if ($interfaces === false) {
    echo "Failed to get network interfaces";
    exit(1);
}

print_r($interfaces);

This code retrieves all network interfaces and prints their details. The output includes interface names, IP addresses, and MAC addresses.

Checking Specific Interface

This demonstrates how to check if a specific network interface exists.

check_interface.php

<?php

declare(strict_types=1);

$interfaces = net_get_interfaces();
$target = "eth0";

if (isset($interfaces[$target])) {
    echo "Interface $target exists";
    print_r($interfaces[$target]);
} else {
    echo "Interface $target not found";
}

This checks for the existence of 'eth0' interface. If found, it displays the interface details including IP configuration and status.

Listing IP Addresses

This example extracts and lists all IPv4 addresses from all interfaces.

list_ips.php

<?php

declare(strict_types=1);

$interfaces = net_get_interfaces();

foreach ($interfaces as $name => $details) {
    if (isset($details['unicast'])) {
        foreach ($details['unicast'] as $addr) {
            if ($addr['family'] == 2) { // AF_INET
                echo "$name: {$addr['address']}\n";
            }
        }
    }
}

This loops through all interfaces and their unicast addresses. It filters for IPv4 addresses (family 2) and prints them with interface names.

Checking Interface Status

This shows how to check if a network interface is up and running.

interface_status.php

<?php

declare(strict_types=1);

$interfaces = net_get_interfaces();
$target = "wlan0";

if (isset($interfaces[$target])) {
    $status = $interfaces[$target]['up'] ? "up" : "down";
    echo "Interface $target is $status";
} else {
    echo "Interface $target not found";
}

This checks the 'up' status of the 'wlan0' interface. The 'up' field indicates whether the interface is currently active and operational.

Getting MAC Addresses

This example demonstrates how to retrieve MAC addresses of all interfaces.

mac_addresses.php

<?php

declare(strict_types=1);

$interfaces = net_get_interfaces();

foreach ($interfaces as $name => $details) {
    if (isset($details['mac'])) {
        echo "$name: {$details['mac']}\n";
    } else {
        echo "$name: No MAC address\n";
    }
}

This lists all interfaces with their MAC addresses. Some interfaces like loopback may not have MAC addresses. The output shows each interface's hardware address.

Best Practices

Error Handling: Always check for false return value
Permission: Ensure script has proper permissions
Caching: Cache results for repeated use
Security: Be cautious with sensitive network info

Source

PHP net_get_interfaces Documentation

This tutorial covered the PHP net_get_interfaces function with practical examples for network interface information retrieval.

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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