function drush_main

8.0.x drush_main()
6.x drush.php drush_main()
7.x drush.php drush_main()
3.x drush.php drush_main()
4.x drush.php drush_main()
5.x drush.php drush_main()
master drush_main()

The main Drush function.

  • Runs "early" option code, if set (see global options).
  • Parses the command line arguments, configuration files and environment.
  • Prepares and executes a Drupal bootstrap, if possible,
  • Dispatches the given command.

function_exists('drush_main') may be used by modules to detect whether they are being called from Drush. See and

Return value

mixed Whatever the given command returns.

2 calls to drush_main()
drush.php in ./drush.php
drush is a PHP script implementing a command line shell for Drupal.
drush_startup in includes/
drush_startup is called once, by the Drush "finder" script -- the "drush" script at the Drush root. It finds the correct Drush "wrapper" or "launcher" script to use, and executes it with process replacement.


includes/, line 25
Preflight, postflight and shutdown code.


function drush_main() {
  // Load Drush core include files, and parse command line arguments.
  if (drush_preflight_prepare() === FALSE) {
    return (1);
  // Start code coverage collection.
  if ($coverage_file = drush_get_option('drush-coverage', FALSE)) {
    drush_set_context('DRUSH_CODE_COVERAGE', $coverage_file);
    xdebug_start_code_coverage(XDEBUG_CC_UNUSED | XDEBUG_CC_DEAD_CODE);

  // Load the global Drush configuration files, and global Drush commands.
  // Find the selected site based on --root, --uri or cwd
  // Preflight the selected site, and load any configuration and commandfiles associated with it.
  // Select and return the bootstrap class.
  $bootstrap = drush_preflight();

  // Reset our bootstrap phase to the beginning

  $return = '';
  if (!drush_get_error()) {
    if ($file = drush_get_option('early', FALSE)) {
      require_once drush_is_absolute_path($file) ? $file : DRUSH_BASE_PATH . DIRECTORY_SEPARATOR . $file;
      $function = 'drush_early_' . basename($file, '.inc');
      if (function_exists($function)) {
        if ($return = $function()) {
          // If the function returns FALSE, we continue and attempt to bootstrap
          // as normal. Otherwise, we exit early with the returned output.
          if ($return === TRUE) {
            $return = '';
    else {
      // Do any necessary preprocessing operations on the command,
      // perhaps handling immediately.
      $command_handled = drush_preflight_command_dispatch();
      if (!$command_handled) {
        $return = $bootstrap->bootstrap_and_dispatch();
  // TODO: Get rid of global variable access here, and just trust
  // the bootstrap object returned from drush_preflight().  This will
  // require some adjustments to Drush bootstrapping.
  // See:
  if ($bootstrap = drush_get_bootstrap_object()) {

  // How strict are we?  If we are very strict, turn 'ok' into 'error'
  // if there are any warnings in the log.
  if (($return == 0) && (drush_get_option('strict') > 1) && drush_log_has_errors()) {
    $return = 1;

  // After this point the drush_shutdown function will run,
  // exiting with the correct exit code.
  return $return;