function drupal_system_listing

Returns information about system object files (modules, themes, etc.).

This function is used to find all or some system object files (module files, theme files, etc.) that exist on the site. It searches in several locations, depending on what type of object you are looking for. For instance, if you are looking for modules and call:

drupal_system_listing("/\\.module\$/", "modules", 'name', 0);

this function will search the site-wide modules directory (i.e., /modules/), your installation profile's directory (i.e., /profiles/your_site_profile/modules/), the all-sites directory (i.e., /sites/all/modules/), and your site-specific directory (i.e., /sites/your_site_dir/modules/), in that order, and return information about all of the files ending in .module in those directories.

The information is returned in an associative array, which can be keyed on the file name ($key = 'filename'), the file name without the extension ($key = 'name'), or the full file stream URI ($key = 'uri'). If you use a key of 'filename' or 'name', files found later in the search will take precedence over files found earlier (unless they belong to a module or theme not compatible with Drupal core); if you choose a key of 'uri', you will get all files found.


string $mask: The preg_match() regular expression for the files to find.

string $directory: The subdirectory name in which the files are found. For example, 'modules' will search in sub-directories of the top-level /modules directory, sub-directories of /sites/all/modules/, etc.

string $key: The key to be used for the associative array returned. Possible values are 'uri', for the file's URI; 'filename', for the basename of the file; and 'name' for the name of the file without the extension. If you choose 'name' or 'filename', only the highest-precedence file will be returned.

int $min_depth: Minimum depth of directories to return files from, relative to each directory searched. For instance, a minimum depth of 2 would find modules inside /modules/node/tests, but not modules directly in /modules/node.

Return value

array An associative array of file objects, keyed on the chosen key. Each element in the array is an object containing file information, with properties:

  • 'uri': Full URI of the file.
  • 'filename': File name.
  • 'name': Name of file without the extension.
7 calls to drupal_system_listing()
DrupalSystemListingTestCase::testDirectoryPrecedence in modules/simpletest/tests/common.test
Test that files in different directories take precedence as expected.
drupal_find_theme_templates in includes/
Allows themes and/or theme engines to easily discover overridden templates.
drupal_required_modules in includes/
Returns an array of modules required by core.
drupal_verify_profile in includes/
Verifies an installation profile for installation.
_drupal_get_filename_perform_file_scan in includes/
Performs a file system scan to search for a system resource.

... See full list

1 string reference to 'drupal_system_listing'
_drupal_get_filename_perform_file_scan in includes/
Performs a file system scan to search for a system resource.


includes/, line 5663


function drupal_system_listing($mask, $directory, $key = 'name', $min_depth = 1) {
    $config = conf_path();
    $searchdir = array(
    $files = array();
    // The 'profiles' directory contains pristine collections of modules and
    // themes as organized by a distribution. It is pristine in the same way
    // that /modules is pristine for core; users should avoid changing anything
    // there in favor of sites/all or sites/<domain> directories.
    $profiles = array();
    $profile = drupal_get_profile();
    // For SimpleTest to be able to test modules packaged together with a
    // distribution we need to include the profile of the parent site (in which
    // test runs are triggered).
    if (drupal_valid_test_ua()) {
        $testing_profile = variable_get('simpletest_parent_profile', FALSE);
        if ($testing_profile && $testing_profile != $profile) {
            $profiles[] = $testing_profile;
    // In case both profile directories contain the same extension, the actual
    // profile always has precedence.
    $profiles[] = $profile;
    foreach ($profiles as $profile) {
        if (file_exists("profiles/{$profile}/{$directory}")) {
            $searchdir[] = "profiles/{$profile}/{$directory}";
    // Always search sites/all/* as well as the global directories.
    $searchdir[] = 'sites/all/' . $directory;
    if (file_exists("{$config}/{$directory}")) {
        $searchdir[] = "{$config}/{$directory}";
    // Get current list of items.
    if (!function_exists('file_scan_directory')) {
        require_once DRUPAL_ROOT . '/includes/';
    foreach ($searchdir as $dir) {
        $files_to_add = file_scan_directory($dir, $mask, array(
            'key' => $key,
            'min_depth' => $min_depth,
        // Duplicate files found in later search directories take precedence over
        // earlier ones, so we want them to overwrite keys in our resulting
        // $files array.
        // The exception to this is if the later file is from a module or theme not
        // compatible with Drupal core. This may occur during upgrades of Drupal
        // core when new modules exist in core while older contrib modules with the
        // same name exist in a directory such as sites/all/modules/.
        foreach (array_intersect_key($files_to_add, $files) as $file_key => $file) {
            // If it has no info file, then we just behave liberally and accept the
            // new resource on the list for merging.
            if (file_exists($info_file = dirname($file->uri) . '/' . $file->name . '.info')) {
                // Get the .info file for the module or theme this file belongs to.
                $info = drupal_parse_info_file($info_file);
                // If the module or theme is incompatible with Drupal core, remove it
                // from the array for the current search directory, so it is not
                // overwritten when merged with the $files array.
                if (isset($info['core']) && $info['core'] != DRUPAL_CORE_COMPATIBILITY) {
        $files = array_merge($files, $files_to_add);
    return $files;

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