This Plugin Activity Logger is a lightweight WordPress must-use plugin that tracks and logs all plugin-related activities, including installation, activation, deactivation, updates, and deletions. It logs each event with a timestamp, the WordPress version, the site’s URL, the plugin name, and the username of the person who performed the action. …

plugin-activity-logger.php

<?php
/**
 * Plugin Name: Plugin Activity Logger
 * Description: Logs plugin installations, activations, deactivations, updates (with from/to versions if available), and deletions. Handles both single and bulk updates. Attempts to log failed updates as well.
 * Version: 3.3
 * Author: Needmore Designs
 */

if (!defined('ABSPATH')) {
    exit; // Exit if accessed directly.
}

define('PLUGIN_ACTIVITY_LOG', WP_CONTENT_DIR . '/plugin-activity.log');

global $plugin_activity_logger_old_versions;
$plugin_activity_logger_old_versions = [];

/**
 * Logs plugin activity to the log file.
 */
function log_plugin_activity($action, $plugin_slug = '', $plugin_name = '', $plugin_version = '') {
    $current_user = wp_get_current_user();
    $username = $current_user->exists() ? $current_user->user_login : 'System/CLI';
    $timestamp = current_time('Y-m-d H:i:s');
    $wordpress_version = get_bloginfo('version');
    $site_url = parse_url(get_bloginfo('url'), PHP_URL_HOST);

    $log_entry = sprintf(
        "[%s] v%s at %s: %s: Plugin '%s' (%s)%s by user '%s'",
        $timestamp,
        $wordpress_version,
        $site_url,
        ucfirst($action),
        $plugin_name,
        $plugin_slug,
        $plugin_version ? " $plugin_version" : '',
        $username
    );

    file_put_contents(PLUGIN_ACTIVITY_LOG, $log_entry . PHP_EOL, FILE_APPEND | LOCK_EX);
}

/**
 * Extract the plugin slug from a plugin path.
 */
function get_plugin_slug($plugin_path) {
    $parts = explode('/', $plugin_path);
    return $parts[0];
}

/**
 * Store the old version of a plugin before update.
 */
function store_old_plugin_version($plugin_path) {
    global $plugin_activity_logger_old_versions;
    $plugin_file = WP_PLUGIN_DIR . '/' . $plugin_path;
    if (file_exists($plugin_file)) {
        $plugin_data = get_plugin_data($plugin_file, false, false);
        $old_version = $plugin_data['Version'] ?? '';
        if ($old_version) {
            $plugin_activity_logger_old_versions[$plugin_path] = $old_version;
        }
    }
}

/**
 * Before the installation (including updates), record old versions for updates.
 */
add_action('upgrader_pre_install', function($hook_extra) {
    // Only run for plugin updates
    if (isset($hook_extra['type']) && $hook_extra['type'] === 'plugin' && isset($hook_extra['action']) && $hook_extra['action'] === 'update') {
        // Single plugin update
        if (!empty($hook_extra['plugin'])) {
            store_old_plugin_version($hook_extra['plugin']);
        }

        // Bulk plugin updates
        if (!empty($hook_extra['plugins']) && is_array($hook_extra['plugins'])) {
            foreach ($hook_extra['plugins'] as $p) {
                store_old_plugin_version($p);
            }
        }
    }
}, 10, 1);

/**
 * Handle plugin installation, updates, and failures.
 */
add_action('upgrader_process_complete', function($upgrader, $options) {
    global $plugin_activity_logger_old_versions;

    if (!isset($options['type']) || $options['type'] !== 'plugin') {
        return;
    }

    $action = $options['action']; // install, update, etc.
    $plugins = $options['plugins'] ?? [];

    // Check for operation failure
    $update_failed = false;
    $error_message = '';

    if (is_wp_error($upgrader->result)) {
        $update_failed = true;
        $error_message = $upgrader->result->get_error_message();
    } elseif (method_exists($upgrader->skin, 'get_errors') && $upgrader->skin->get_errors()->get_error_messages()) {
        $update_failed = true;
        $errors = $upgrader->skin->get_errors()->get_error_messages();
        $error_message = implode('; ', $errors);
    }

    foreach ($plugins as $plugin_path) {
        $plugin_slug = get_plugin_slug($plugin_path);
        $plugin_file = WP_PLUGIN_DIR . '/' . $plugin_path;
        $plugin_data = file_exists($plugin_file) ? get_plugin_data($plugin_file, false, false) : [];
        $plugin_name = $plugin_data['Name'] ?? $plugin_slug;
        $new_version = $plugin_data['Version'] ?? '';

        // Attempt to retrieve old version
        $old_version = $plugin_activity_logger_old_versions[$plugin_path] ?? '';

        // If no old version found, try $upgrader->skin->plugin_info
        // Sometimes WP_Upgrader stores info about the old plugin there.
        if (!$old_version && isset($upgrader->skin->plugin_info) && is_array($upgrader->skin->plugin_info)) {
            $old_version = $upgrader->skin->plugin_info['Version'] ?? $old_version;
        }

        if ($action === 'install') {
            if ($update_failed) {
                log_plugin_activity('install (failed)', $plugin_slug, $plugin_name, "Error: $error_message");
            } else {
                log_plugin_activity('install', $plugin_slug, $plugin_name, $new_version ? "v{$new_version}" : '');
            }
        } elseif ($action === 'update') {
            if ($update_failed) {
                log_plugin_activity('update (failed)', $plugin_slug, $plugin_name, "Error: $error_message");
            } else {
                // If we have old and new versions and they differ, show "from vOld to vNew"
                if ($old_version && $new_version && $old_version !== $new_version) {
                    log_plugin_activity('update', $plugin_slug, $plugin_name, "from v{$old_version} to v{$new_version}");
                } else {
                    // Fall back to just the new version
                    log_plugin_activity('update', $plugin_slug, $plugin_name, $new_version ? "v{$new_version}" : '');
                }
            }
        }
    }
}, 10, 2);

/**
 * Log plugin deletions.
 */
add_action('deleted_plugin', function($plugin_path) {
    $plugin_slug = get_plugin_slug($plugin_path);
    $plugin_name = basename($plugin_slug, '.php');
    log_plugin_activity('delete', $plugin_slug, $plugin_name);
});

/**
 * Log activation.
 */
add_action('activated_plugin', function($plugin_path) {
    $plugin_slug = get_plugin_slug($plugin_path);
    $plugin_file = WP_PLUGIN_DIR . '/' . $plugin_path;
    $plugin_data = file_exists($plugin_file) ? get_plugin_data($plugin_file, false, false) : [];
    $plugin_name = $plugin_data['Name'] ?? $plugin_slug;
    $plugin_version = $plugin_data['Version'] ?? '';
    log_plugin_activity('activate', $plugin_slug, $plugin_name, $plugin_version ? "v{$plugin_version}" : '');
});

/**
 * Log deactivation.
 */
add_action('deactivated_plugin', function($plugin_path) {
    $plugin_slug = get_plugin_slug($plugin_path);
    $plugin_file = WP_PLUGIN_DIR . '/' . $plugin_path;
    $plugin_data = file_exists($plugin_file) ? get_plugin_data($plugin_file, false, false) : [];
    $plugin_name = $plugin_data['Name'] ?? $plugin_slug;
    $plugin_version = $plugin_data['Version'] ?? '';
    log_plugin_activity('deactivate', $plugin_slug, $plugin_name, $plugin_version ? "v{$plugin_version}" : '');
});

/**
 * Initialization log entry.
 */
function initialize_plugin_activity_log() {
    if (!file_exists(PLUGIN_ACTIVITY_LOG)) {
        $timestamp = current_time('Y-m-d H:i:s');
        $wordpress_version = get_bloginfo('version');
        $site_url = parse_url(get_bloginfo('url'), PHP_URL_HOST);

        $log_entry = sprintf(
            "[%s] v%s at %s: Initialize: Plugin Activity Log Initialized by user 'System/CLI'",
            $timestamp,
            $wordpress_version,
            $site_url
        );

        file_put_contents(PLUGIN_ACTIVITY_LOG, $log_entry . PHP_EOL, LOCK_EX);
    }
}
initialize_plugin_activity_log();