--- /dev/null
+#!/usr/bin/env php
+<?php
+
+/**
+ * This is the Drush "finder" script, which is one part of the
+ * Drush dispatching chain. This is the script that
+ * should appear in your global $PATH, or, if using Composer
+ * (as usually the case), will be found in your vendor/bin directory.
+ *
+ *
+ * - Never copy this script to your site root. Copy examples/drush instead.
+ *
+ * - Never copy this script to a directory other than its install directory.
+ * Symlink to it instead.
+ *
+ *
+ * OVERVIEW OF DRUSH FINDER / WRAPPER / LAUNCHER SCRIPTS
+ *
+ * When the user types "drush", up to three scripts might be
+ * involved in the initial launch:
+ *
+ * "drush finder" -> "drush wrapper" -> "drush launcher".
+ *
+ * Brief description of each:
+ *
+ * - Drush finder: Finds the right Drush script and calls it.
+ * - Drush wrapper: Contains user customizations to options.
+ * - Drush launcher: Excutes drush.php.
+ *
+ * A full explanation of each script follows.
+ *
+ *
+ * DRUSH FINDER
+ *
+ * - The "drush" script on the user's global $PATH
+ * - It's goal is to find the correct site-local Drush to run.
+ *
+ * The Drush finder will locate the correct site-local Drush to use
+ * by examining:
+ *
+ * a) The --root option
+ * b) The site set via `drush site set` in the current terminal
+ * c) The cwd
+ *
+ * If no site-local Drush is found, then the global Drush will be
+ * used. The Drush finder assumes that the global Drush is the
+ * "Drush launcher" found in the same directory as the Drush finder itself.
+ *
+ * If a site-local Drush is found, then the Drush finder will call
+ * either the "Drush wrapper", if it exists, or the "Drush launcher" if
+ * there is no wrapper script.
+ *
+ *
+ * DRUSH WRAPPER
+ *
+ * - The drush.wrapper script that the user optionally copies and edits.
+ * - Its goal is to allow the user to add options when --local is in use
+ *
+ * The Drush "wrapper" is found at examples/drush.wrapper, and may optionally
+ * be copied to __ROOT__ by the user. It may be named either
+ * "drush" or "drush.wrapper". It will call the "Drush launcher"
+ * for the same site that it is located in. It adds the --local flag; the
+ * user is encouraged to add other options to the "Drush wrapper", e.g. to set
+ * the location where aliases and global commandfiles can be found.
+ * The Drush "finder" script always calls the "Drush wrapper" if it exists;
+ * however, if the user does not want to customize the early options of
+ * the site-local Drush (site-alias locations, etc.), then the wrapper does not
+ * need to be used.
+ *
+ *
+ * DRUSH LAUNCHER
+ *
+ * - The "drush.launcher" script in vendor/bin
+ * - The bash script formerly called "drush"
+ *
+ * The "Drush launcher" is the traditional script that identifies PHP and
+ * sets up to call drush.php. It is called by the "Drush wrapper", or
+ * directly by the "Drush launcher" if there is no "Drush wrapper" in use.
+ *
+ *
+ * LOCATIONS FOR THESE SCRIPTS
+ *
+ * "Drush finder" : __ROOT__/vendor/bin/drush (composer install)
+ * __DRUSH__/drush (source)
+ *
+ * "Drush wrapper" : __ROOT__/drush (copied by user)
+ * __DRUSH__/examples/drush.wrapper (source)
+ *
+ * "Drush launcher" : __ROOT__/vendor/bin/drush.launcher (composer install)
+ * __DRUSH__/drush.launcher (source)
+ *
+ *
+ * BACKEND CALL DISPATCHING
+ *
+ * Backend calls are typically set up to call the "drush" script in the $PATH,
+ * or perhaps some might call __ROOT__/vendor/bin/drush directly, by way
+ * of the "drush-script" element in a site alias. In either event, this is
+ * the "drush finder" script.
+ *
+ * The backend call will always set --root. The "Drush finder" script
+ * always favors the site-local Drush stored with the site indicated by the
+ * --root option, if it exists. If there is no site-local Drush, then the
+ * "Drush finder" will behave as usual (i.e., it will end up calling the
+ * "Drush launcher" located next to it).
+ *
+ * This should always get you the correct "Drush" for local and remote calls.
+ * Note that it is also okay for aliases to specify a path directly to
+ * drush.launcher, in instances where it is known that a recent version of
+ * Drush is installed on the remote end.
+ */
+
+if (!function_exists("drush_startup")) {
+ include __DIR__ . '/includes/startup.inc';
+}
+drush_startup($argv);