root/trunk/wp-admin/includes/plugin.php

<?php
/**
 * WordPress Plugin Administration API
 *
 * @package WordPress
 * @subpackage Administration
 */

/**
 * Parse the plugin contents to retrieve plugin's metadata.
 *
 * The metadata of the plugin's data searches for the following in the plugin's
 * header. All plugin data must be on its own line. For plugin description, it
 * must not have any newlines or only parts of the description will be displayed
 * and the same goes for the plugin data. The below is formatted for printing.
 *
 * <code>
 * /*
 * Plugin Name: Name of Plugin
 * Plugin URI: Link to plugin information
 * Description: Plugin Description
 * Author: Plugin author's name
 * Author URI: Link to the author's web site
 * Version: Must be set in the plugin for WordPress 2.3+
 * Text Domain: Optional. Unique identifier, should be same as the one used in
 *        plugin_text_domain()
 * Domain Path: Optional. Only useful if the translations are located in a
 *        folder above the plugin's base path. For example, if .mo files are
 *        located in the locale folder then Domain Path will be "/locale/" and
 *        must have the first slash. Defaults to the base folder the plugin is
 *        located in.
 *  * / # Remove the space to close comment
 * </code>
 *
 * Plugin data returned array contains the following:
 *        'Name' - Name of the plugin, must be unique.
 *        'Title' - Title of the plugin and the link to the plugin's web site.
 *        'Description' - Description of what the plugin does and/or notes
 *        from the author.
 *        'Author' - The author's name
 *        'AuthorURI' - The authors web site address.
 *        'Version' - The plugin version number.
 *        'PluginURI' - Plugin web site address.
 *        'TextDomain' - Plugin's text domain for localization.
 *        'DomainPath' - Plugin's relative directory path to .mo files.
 *
 * Some users have issues with opening large files and manipulating the contents
 * for want is usually the first 1kiB or 2kiB. This function stops pulling in
 * the plugin contents when it has all of the required plugin data.
 *
 * The first 8kiB of the file will be pulled in and if the plugin data is not
 * within that first 8kiB, then the plugin author should correct their plugin
 * and move the plugin data headers to the top.
 *
 * The plugin file is assumed to have permissions to allow for scripts to read
 * the file. This is not checked however and the file is only opened for
 * reading.
 *
 * @link http://trac.wordpress.org/ticket/5651 Previous Optimizations.
 * @link http://trac.wordpress.org/ticket/7372 Further and better Optimizations.
 * @since 1.5.0
 *
 * @param string $plugin_file Path to the plugin file
 * @param bool $markup If the returned data should have HTML markup applied
 * @param bool $translate If the returned data should be translated
 * @return array See above for description.
 */
function get_plugin_data( $plugin_file, $markup = true, $translate = true ) {
    // We don't need to write to the file, so just open for reading.
    $fp = fopen($plugin_file, 'r');

    // Pull only the first 8kiB of the file in.
    $plugin_data = fread( $fp, 8192 );

    // PHP will close file handle, but we are good citizens.
    fclose($fp);

    preg_match( '|Plugin Name:(.*)$|mi', $plugin_data, $name );
    preg_match( '|Plugin URI:(.*)$|mi', $plugin_data, $uri );
    preg_match( '|Version:(.*)|i', $plugin_data, $version );
    preg_match( '|Description:(.*)$|mi', $plugin_data, $description );
    preg_match( '|Author:(.*)$|mi', $plugin_data, $author_name );
    preg_match( '|Author URI:(.*)$|mi', $plugin_data, $author_uri );
    preg_match( '|Text Domain:(.*)$|mi', $plugin_data, $text_domain );
    preg_match( '|Domain Path:(.*)$|mi', $plugin_data, $domain_path );

    foreach ( array( 'name', 'uri', 'version', 'description', 'author_name', 'author_uri', 'text_domain', 'domain_path' ) as $field ) {
        if ( !empty( ${$field} ) )
            ${$field} = trim(${$field}[1]);
        else
            ${$field} = '';
    }

    $plugin_data = array(
                'Name' => $name, 'Title' => $name, 'PluginURI' => $uri, 'Description' => $description,
                'Author' => $author_name, 'AuthorURI' => $author_uri, 'Version' => $version,
                'TextDomain' => $text_domain, 'DomainPath' => $domain_path
                );
    if ( $markup || $translate )
        $plugin_data = _get_plugin_data_markup_translate($plugin_data, $markup, $translate);
    return $plugin_data;
}

function _get_plugin_data_markup_translate($plugin_data, $markup = true, $translate = true) {

    //Translate fields
    if( $translate && ! empty($plugin_data['TextDomain']) ) {
        if( ! empty( $plugin_data['DomainPath'] ) )
            load_plugin_textdomain($plugin_data['TextDomain'], dirname($plugin_file). $plugin_data['DomainPath']);
        else
            load_plugin_textdomain($plugin_data['TextDomain'], dirname($plugin_file));

        foreach ( array('Name', 'PluginURI', 'Description', 'Author', 'AuthorURI', 'Version') as $field )
            $plugin_data[ $field ] = translate($plugin_data[ $field ], $plugin_data['TextDomain']);
    }

    //Apply Markup
    if ( $markup ) {
        if ( ! empty($plugin_data['PluginURI']) && ! empty($plugin_data['Name']) )
            $plugin_data['Title'] = '<a href="' . $plugin_data['PluginURI'] . '" title="' . __( 'Visit plugin homepage' ) . '">' . $plugin_data['Name'] . '</a>';
        else
            $plugin_data['Title'] = $plugin_data['Name'];

        if ( ! empty($plugin_data['AuthorURI']) )
            $plugin_data['Author'] = '<a href="' . $plugin_data['AuthorURI'] . '" title="' . __( 'Visit author homepage' ) . '">' . $plugin_data['Author'] . '</a>';

        $plugin_data['Description'] = wptexturize( $plugin_data['Description'] );
        if( ! empty($plugin_data['Author']) )
            $plugin_data['Description'] .= ' <cite>' . sprintf( __('By %s'), $plugin_data['Author'] ) . '.</cite>';
    }

    $plugins_allowedtags = array('a' => array('href' => array(),'title' => array()),'abbr' => array('title' => array()),'acronym' => array('title' => array()),'code' => array(),'em' => array(),'strong' => array());

    // Sanitize all displayed data
    $plugin_data['Title']       = wp_kses($plugin_data['Title'], $plugins_allowedtags);
    $plugin_data['Version']     = wp_kses($plugin_data['Version'], $plugins_allowedtags);
    $plugin_data['Description'] = wp_kses($plugin_data['Description'], $plugins_allowedtags);
    $plugin_data['Author']      = wp_kses($plugin_data['Author'], $plugins_allowedtags);

    return $plugin_data;
}

/**
 * Check the plugins directory and retrieve all plugin files with plugin data.
 *
 * WordPress only supports plugin files in the base plugins directory
 * (wp-content/plugins) and in one directory above the plugins directory
 * (wp-content/plugins/my-plugin). The file it looks for has the plugin data and
 * must be found in those two locations. It is recommended that do keep your
 * plugin files in directories.
 *
 * The file with the plugin data is the file that will be included and therefore
 * needs to have the main execution for the plugin. This does not mean
 * everything must be contained in the file and it is recommended that the file
 * be split for maintainability. Keep everything in one file for extreme
 * optimization purposes.
 *
 * @since unknown
 *
 * @param string $plugin_folder Optional. Relative path to single plugin folder.
 * @return array Key is the plugin file path and the value is an array of the plugin data.
 */
function get_plugins($plugin_folder = '') {

    if ( ! $cache_plugins = wp_cache_get('plugins', 'plugins') )
        $cache_plugins = array();

    if ( isset($cache_plugins[ $plugin_folder ]) )
        return $cache_plugins[ $plugin_folder ];

    $wp_plugins = array ();
    $plugin_root = WP_PLUGIN_DIR;
    if( !empty($plugin_folder) )
        $plugin_root .= $plugin_folder;

    // Files in wp-content/plugins directory
    $plugins_dir = @ opendir( $plugin_root);
    if ( $plugins_dir ) {
        while (($file = readdir( $plugins_dir ) ) !== false ) {
            if ( substr($file, 0, 1) == '.' )
                continue;
            if ( is_dir( $plugin_root.'/'.$file ) ) {
                $plugins_subdir = @ opendir( $plugin_root.'/'.$file );
                if ( $plugins_subdir ) {
                    while (($subfile = readdir( $plugins_subdir ) ) !== false ) {
                        if ( substr($subfile, 0, 1) == '.' )
                            continue;
                        if ( substr($subfile, -4) == '.php' )
                            $plugin_files[] = "$file/$subfile";
                    }
                }
            } else {
                if ( substr($file, -4) == '.php' )
                    $plugin_files[] = $file;
            }
        }
    }
    @closedir( $plugins_dir );
    @closedir( $plugins_subdir );

    if ( !$plugins_dir || !$plugin_files )
        return $wp_plugins;

    foreach ( $plugin_files as $plugin_file ) {
        if ( !is_readable( "$plugin_root/$plugin_file" ) )
            continue;

        $plugin_data = get_plugin_data( "$plugin_root/$plugin_file", false, false ); //Do not apply markup/translate as it'll be cached.

        if ( empty ( $plugin_data['Name'] ) )
            continue;

        $wp_plugins[plugin_basename( $plugin_file )] = $plugin_data;
    }

    uasort( $wp_plugins, create_function( '$a, $b', 'return strnatcasecmp( $a["Name"], $b["Name"] );' ));

    $cache_plugins[ $plugin_folder ] = $wp_plugins;
    wp_cache_set('plugins', $cache_plugins, 'plugins');

    return $wp_plugins;
}

/**
 * Check whether the plugin is active by checking the active_plugins list.
 *
 * @since 2.5.0
 *
 * @param string $plugin Base plugin path from plugins directory.
 * @return bool True, if in the active plugins list. False, not in the list.
 */
function is_plugin_active($plugin) {
    return in_array($plugin, get_option('active_plugins'));
}

/**
 * Attempts activation of plugin in a "sandbox" and redirects on success.
 *
 * A plugin that is already activated will not attempt to be activated again.
 *
 * The way it works is by setting the redirection to the error before trying to
 * include the plugin file. If the plugin fails, then the redirection will not
 * be overwritten with the success message. Also, the options will not be
 * updated and the activation hook will not be called on plugin error.
 *
 * It should be noted that in no way the below code will actually prevent errors
 * within the file. The code should not be used elsewhere to replicate the
 * "sandbox", which uses redirection to work.
 * {@source 13 1}
 *
 * If any errors are found or text is outputted, then it will be captured to
 * ensure that the success redirection will update the error redirection.
 *
 * @since unknown
 *
 * @param string $plugin Plugin path to main plugin file with plugin data.
 * @param string $redirect Optional. URL to redirect to.
 * @return WP_Error|null WP_Error on invalid file or null on success.
 */
function activate_plugin($plugin, $redirect = '') {
    $current = get_option('active_plugins');
    $plugin = plugin_basename(trim($plugin));

    $valid = validate_plugin($plugin);
    if ( is_wp_error($valid) )
        return $valid;

    if ( !in_array($plugin, $current) ) {
        if ( !empty($redirect) )
            wp_redirect(add_query_arg('_error_nonce', wp_create_nonce('plugin-activation-error_' . $plugin), $redirect)); // we'll override this later if the plugin can be included without fatal error
        ob_start();
        @include(WP_PLUGIN_DIR . '/' . $plugin);
        $current[] = $plugin;
        sort($current);
        update_option('active_plugins', $current);
        do_action('activate_' . $plugin);
        ob_end_clean();
    }

    return null;
}

/**
 * Deactivate a single plugin or multiple plugins.
 *
 * The deactivation hook is disabled by the plugin upgrader by using the $silent
 * parameter.
 *
 * @since unknown
 *
 * @param string|array $plugins Single plugin or list of plugins to deactivate.
 * @param bool $silent Optional, default is false. Prevent calling deactivate hook.
 */
function deactivate_plugins($plugins, $silent= false) {
    $current = get_option('active_plugins');

    if ( !is_array($plugins) )
        $plugins = array($plugins);

    foreach ( $plugins as $plugin ) {
        $plugin = plugin_basename($plugin);
        if( ! is_plugin_active($plugin) )
            continue;
        array_splice($current, array_search( $plugin, $current), 1 ); // Fixed Array-fu!
        if ( ! $silent ) //Used by Plugin updater to internally deactivate plugin, however, not to notify plugins of the fact to prevent plugin output.
            do_action('deactivate_' . trim( $plugin ));
    }

    update_option('active_plugins', $current);
}

/**
 * Activate multiple plugins.
 *
 * When WP_Error is returned, it does not mean that one of the plugins had
 * errors. It means that one or more of the plugins file path was invalid.
 *
 * The execution will be halted as soon as one of the plugins has an error.
 *
 * @since unknown
 *
 * @param string|array $plugins
 * @param string $redirect Redirect to page after successful activation.
 * @return bool|WP_Error True when finished or WP_Error if there were errors during a plugin activation.
 */
function activate_plugins($plugins, $redirect = '') {
    if ( !is_array($plugins) )
        $plugins = array($plugins);

    $errors = array();
    foreach ( (array) $plugins as $plugin ) {
        if ( !empty($redirect) )
            $redirect = add_query_arg('plugin', $plugin, $redirect);
        $result = activate_plugin($plugin, $redirect);
        if ( is_wp_error($result) )
            $errors[$plugin] = $result;
    }

    if ( !empty($errors) )
        return new WP_Error('plugins_invalid', __('One of the plugins is invalid.'), $errors);

    return true;
}

/**
 * Remove directory and files of a plugin for a single or list of plugin(s).
 *
 * If the plugins parameter list is empty, false will be returned. True when
 * completed.
 *
 * @since unknown
 *
 * @param array $plugins List of plugin
 * @param string $redirect Redirect to page when complete.
 * @return mixed
 */
function delete_plugins($plugins, $redirect = '' ) {
    global $wp_filesystem;

    if( empty($plugins) )
        return false;

    $checked = array();
    foreach( $plugins as $plugin )
        $checked[] = 'checked[]=' . $plugin;

    ob_start();
    $url = wp_nonce_url('plugins.php?action=delete-selected&verify-delete=1&' . implode('&', $checked), 'bulk-manage-plugins');
    if ( false === ($credentials = request_filesystem_credentials($url)) ) {
        $data = ob_get_contents();
        ob_end_clean();
        if( ! empty($data) ){
            include_once( ABSPATH . 'wp-admin/admin-header.php');
            echo $data;
            include( ABSPATH . 'wp-admin/admin-footer.php');
            exit;
        }
        return;
    }

    if ( ! WP_Filesystem($credentials) ) {
        request_filesystem_credentials($url, '', true); //Failed to connect, Error and request again
        $data = ob_get_contents();
        ob_end_clean();
        if( ! empty($data) ){
            include_once( ABSPATH . 'wp-admin/admin-header.php');
            echo $data;
            include( ABSPATH . 'wp-admin/admin-footer.php');
            exit;
        }
        return;
    }

    if ( $wp_filesystem->errors->get_error_code() ) {
        return $wp_filesystem->errors;
    }

    if ( ! is_object($wp_filesystem) )
        return new WP_Error('fs_unavailable', __('Could not access filesystem.'));

    if ( $wp_filesystem->errors->get_error_code() )
        return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);

    //Get the base plugin folder
    $plugins_dir = $wp_filesystem->wp_plugins_dir();
    if ( empty($plugins_dir) )
        return new WP_Error('fs_no_plugins_dir', __('Unable to locate WordPress Plugin directory.'));

    $plugins_dir = trailingslashit( $plugins_dir );

    $errors = array();

    foreach( $plugins as $plugin_file ) {
        // Run Uninstall hook
        if ( is_uninstallable_plugin( $plugin_file ) )
            uninstall_plugin($plugin_file);

        $this_plugin_dir = trailingslashit( dirname($plugins_dir . $plugin_file) );
        // If plugin is in its own directory, recursively delete the directory.
        if ( strpos($plugin_file, '/') && $this_plugin_dir != $plugins_dir ) //base check on if plugin includes directory seperator AND that its not the root plugin folder
            $deleted = $wp_filesystem->delete($this_plugin_dir, true);
        else
            $deleted = $wp_filesystem->delete($plugins_dir . $plugin_file);

        if ( ! $deleted )
            $errors[] = $plugin_file;
    }

    if( ! empty($errors) )
        return new WP_Error('could_not_remove_plugin', sprintf(__('Could not fully remove the plugin(s) %s'), implode(', ', $errors)) );

    return true;
}

function validate_active_plugins() {
    $check_plugins = get_option('active_plugins');

    // Sanity check.  If the active plugin list is not an array, make it an
    // empty array.
    if ( !is_array($check_plugins) ) {
        update_option('active_plugins', array());
        return;
    }

    //Invalid is any plugin that is deactivated due to error.
    $invalid = array();

    // If a plugin file does not exist, remove it from the list of active
    // plugins.
    foreach ( $check_plugins as $check_plugin ) {
        $result = validate_plugin($check_plugin);
        if ( is_wp_error( $result ) ) {
            $invalid[$check_plugin] = $result;
            deactivate_plugins( $check_plugin, true);
        }
    }
    return $invalid;
}

/**
 * Validate the plugin path.
 *
 * Checks that the file exists and {@link validate_file() is valid file}.
 *
 * @since unknown
 *
 * @param string $plugin Plugin Path
 * @return WP_Error|int 0 on success, WP_Error on failure.
 */
function validate_plugin($plugin) {
    if ( validate_file($plugin) )
        return new WP_Error('plugin_invalid', __('Invalid plugin path.'));
    if ( ! file_exists(WP_PLUGIN_DIR . '/' . $plugin) )
        return new WP_Error('plugin_not_found', __('Plugin file does not exist.'));

    return 0;
}

/**
 * Whether the plugin can be uninstalled.
 *
 * @since 2.7.0
 *
 * @param string $plugin Plugin path to check.
 * @return bool Whether plugin can be uninstalled.
 */
function is_uninstallable_plugin($plugin) {
    $file = plugin_basename($plugin);

    $uninstallable_plugins = (array) get_option('uninstall_plugins');
    if ( isset( $uninstallable_plugins[$file] ) || file_exists( WP_PLUGIN_DIR . '/' . dirname($file) . '/uninstall.php' ) )
        return true;

    return false;
}

/**
 * Uninstall a single plugin.
 *
 * Calls the uninstall hook, if it is available.
 *
 * @since 2.7.0
 *
 * @param string $plugin Relative plugin path from Plugin Directory.
 */
function uninstall_plugin($plugin) {
    $file = plugin_basename($plugin);

    $uninstallable_plugins = (array) get_option('uninstall_plugins');
    if ( file_exists( WP_PLUGIN_DIR . '/' . dirname($file) . '/uninstall.php' ) ) {
        if ( isset( $uninstallable_plugins[$file] ) ) {
            unset($uninstallable_plugins[$file]);
            update_option('uninstall_plugins', $uninstallable_plugins);
        }
        unset($uninstallable_plugins);

        define('WP_UNINSTALL_PLUGIN', $file);
        include WP_PLUGIN_DIR . '/' . dirname($file) . '/uninstall.php';

        return true;
    }

    if ( isset( $uninstallable_plugins[$file] ) ) {
        $callable = $uninstallable_plugins[$file];
        unset($uninstallable_plugins[$file]);
        update_option('uninstall_plugins', $uninstallable_plugins);
        unset($uninstallable_plugins);

        include WP_PLUGIN_DIR . '/' . $file;

        add_action( 'uninstall_' . $file, $callable );
        do_action( 'uninstall_' . $file );
    }
}

//
// Menu
//

function add_menu_page( $page_title, $menu_title, $access_level, $file, $function = '', $icon_url = '' ) {
    global $menu, $admin_page_hooks;

    $file = plugin_basename( $file );

    $admin_page_hooks[$file] = sanitize_title( $menu_title );

    $hookname = get_plugin_page_hookname( $file, '' );
    if (!empty ( $function ) && !empty ( $hookname ))
        add_action( $hookname, $function );

    if ( empty($icon_url) )
        $icon_url = 'images/generic.png';
    
    $menu[] = array ( $menu_title, $access_level, $file, $page_title, 'menu-top ' . $hookname, $hookname, $icon_url );