This information is based on: #847686: Processing batch jobs with drush

If you are not familiar with the Drupal Batch API, see this handbook page: Batch API

Executing batch jobs that have already been set

You can execute a batch job that has already been set in the database on the command line with the command:
$ drush batch-process N
where N is the id of your batch job in the database.

Stub functions: Executing batch jobs with scripts

The following stubs can be used as templates for creating and executing batch jobs using (e.g.) drush php-eval or drush scr.

/**
 * Set and process a batch job with drush.
 *
 * @param $batch_args
 *     Whatever arguments you wish to pass to the batch job.
 */
function mymodule_drush_batchname($batch_args) {
  // Set arguments for fetching the dataset and setting the operations.  
  // (Insert your logic here.)
  $data_args;
  $op_args;

  // Fetch the data to operate on using a function in mymodule.
  // Assume for this example that mymodule_data() returns a list of records to process.
  $dataset = mymodule_data($data_args);

  // Add operations to the batch job for all of $dataset.
  mymodule_drush_batchname_operations($batch, $dataset);
    
  // Set and configure the batch.
  batch_set($batch);
  $batch =& batch_get();
  $batch['progressive'] = FALSE;
  
  // You may also need to tell the batch which file your function is located in, using $batch['file']. See below.

  // Process the batch.
  drush_backend_batch_process();
}

/**
 *  Create operations for mymodule_drush_batchname.
 *  Assume we want to do two operations on each element of the dataset,
 *  mymodule_operation_a() and mymodule_operation_b().
 *
 * @param &$batch
 *     The batch job we are creating.
 * @param &$dataset
 *     The dataset to process.  
 *     (Assumed here to be an array with each row containing the data needed by mymodule.)
 * @param $op_args
 *     Whatever args you wish to pass to set the operations. 
 */ 
function mymodule_drush_batchname_operations(&$batch, &$dataset, $op_args) {

  // Set arguments for mymodule_operation_a and mymodule_operation_b.  
  // (Insert your logic here.)
  $op_a_additional_args;
  $op_b_additional_args;

  // Add the desired operations for each element in $dataset.
  foreach ($dataset as $element) {

    // These are functions in mymodule for operating on data in the format of $element:

    // mymodule_operation_a($element, $op_a_additional_args)
    $a_args = array($element, $op_a_additional_args);
    $batch['operations'][] = array('mymodule_operation_a', $a_args); 

    // mymodule_operation_b($element, $op_b_additional_args)
    $b_args = array($element, $op_b_additional_args);
    $batch['operations'][] = array('mymodule_operation_b', $b_args);    
  }
}

Telling the batch where your functions are

If your function does not run, the batch process WILL NOT tell you. It will just fail silently.

In that case, you may also need to provide the path to the file which holds the function(s) you wish to be executed by the batch, if they are not core Drupal functions (e.g. you created them in a script file or in a module).

You will definitely need to do this if the function(s) is not in a module or if it is not in a .module file (e.g. .inc file, see Batch API documentation: http://drupal.org/node/180528).

If the functions are in a module and in a .module file, you technically should not need to do this -- but might have to anyway.

Assuming your callback function, mymodule_operation_a, is located in a file named batch_example.inc in the module directory mydrushmodule, you would include the following line before drush processes the batch:

$batch['file'] = drupal_get_path('module', 'mydrushmodule') . '/batch_example.inc';

If your function is actually in the .module file, try setting the file to the path to the module file:

$batch['file'] = drupal_get_path('module', 'mydrushmodule') . '/mydrushmodule.module';

Helpful Links

• http://www.metaltoad.com/blog/using-drupal-batch-api