Source

File: wp-admin/includes/plugin.php

function get_dropins() {
	$dropins      = array();
	$plugin_files = array();

	$_dropins = _get_dropins();

	// Files in wp-content directory.
	$plugins_dir = @opendir( WP_CONTENT_DIR );
	if ( $plugins_dir ) {
		while ( ( $file = readdir( $plugins_dir ) ) !== false ) {
			if ( isset( $_dropins[ $file ] ) ) {
				$plugin_files[] = $file;
			}
		}
	} else {
		return $dropins;
	}

	closedir( $plugins_dir );

	if ( empty( $plugin_files ) ) {
		return $dropins;
	}

	foreach ( $plugin_files as $plugin_file ) {
		if ( ! is_readable( WP_CONTENT_DIR . "/$plugin_file" ) ) {
			continue;
		}

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

		if ( empty( $plugin_data['Name'] ) ) {
			$plugin_data['Name'] = $plugin_file;
		}

		$dropins[ $plugin_file ] = $plugin_data;
	}

	uksort( $dropins, 'strnatcasecmp' );

	return $dropins;
}