Complete Guide to Writing Plugins in DirectAdmin: Structure, PHP Handling, GET/POST Support, and Optional Templates

1. Introduction to DirectAdmin Plugins

DirectAdmin’s plugin system allows developers to extend the control panel with custom functionality. A plugin is essentially a collection of files—scripts, HTML templates, and hook definitions—that integrate with the DirectAdmin interface.

To get started, DirectAdmin provides a sample plugin:

• hello_world.tar.gz — a simple example demonstrating plugin structure and hooks.

Plugins can:

• Add new menu items to DirectAdmin skins
• Execute custom scripts
• Send files or raw output directly to the browser
• Bypass the default DirectAdmin header/footer “bubble”
• Control HTTP headers and socket behavior

More advanced features are documented in the DirectAdmin versions system.

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2. Running PHP with a Custom php.ini

If your plugin requires a custom php.ini, you can specify it directly in the shebang line of your PHP script.

2.1 Using a Custom php.ini

#!/usr/local/bin/php -nc /usr/local/directadmin/plugins/PLUGIN_NAME/yourphp.ini

Important: The -n option disables loading of the system-wide php.ini, preventing duplicate module loading (e.g., ionCube, Zend).

2.2 Running PHP Without Any php.ini

#!/usr/local/bin/php -n

This forces PHP to use internal defaults only.

2.3 Debugging Shebang Issues

If your script fails to run, ensure it is saved in UNIX format. Convert using:

yum install dos2unix
dos2unix index.html

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3. Using $_GET and $_POST Inside Plugins

DirectAdmin plugins run under CLI PHP (/usr/local/bin/php), which does not automatically populate $_GET and $_POST. Instead, DirectAdmin passes data through environment variables.

You can reconstruct these arrays manually:

// Build $_GET
$_GET = Array();
$QUERY_STRING = getenv('QUERY_STRING');
if ($QUERY_STRING != "") {
    parse_str(html_entity_decode($QUERY_STRING), $get_array);
    foreach ($get_array as $key => $value) {
        $_GET[urldecode($key)] = urldecode($value);
    }
}

// Build $_POST
$_POST = Array();
$POST_STRING = getenv('POST');
if ($POST_STRING != "") {
    parse_str(html_entity_decode($POST_STRING), $post_array);
    foreach ($post_array as $key => $value) {
        $_POST[urldecode($key)] = urldecode($value);
    }
}

This allows your plugin to behave similarly to a normal PHP web application.

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4. Optional Template: plugin_iframe.html

DirectAdmin supports an optional template for plugins that use:

iframe=yes

By default, DirectAdmin wraps plugin output in a hardcoded iframe layout. If you want full control over the iframe HTML, create:

/usr/local/directadmin/data/templates/custom/plugin_iframe.html

Example template:

    
    


    

        |OUTPUT|
    

This is especially useful for debugging or for plugins that require custom styling.

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5. Summary

DirectAdmin’s plugin system is lightweight, flexible, and easy to extend. By combining:

• custom scripts
• custom php.ini handling
• GET/POST reconstruction
• optional iframe templates

you can build powerful integrations that feel native inside the DirectAdmin interface.