Processing batch jobs with drush

There are no docs at this time. The updatedb command is the only core command to use drush's implementation of batch api. Study it for guidance. Its a bit complex, unfortunately.

I tried looking at the updatedb command but I couldnt make it work.

I have this drush command building up a batch

function import_drush_import_fast($start, $stop) {
  $result = db_query("SELECT * FROM {importer_17} WHERE id > %d AND id < %d", $start, $stop);
	
  import_drush_import_fast_operations($batch, $result);
    
  batch_set($batch);
  
  $batch =& batch_get();
  
  $batch['progressive'] = FALSE;
  
  drush_backend_batch_process();
}

/**
 *  Creates operations for importing bedrijf nodes
 */ 
function import_drush_import_fast_operations(&$batch, &$result) {
  while ($fields = db_fetch_array($result)) {    
    array_shift($fields);   
    $fields_out = array();
    foreach ($fields as $field) {
      $fields_out[] = $field;
    }

    $batch['operations'][] = array('import_create_bedrijf_nodes', array($fields_out, TRUE, 17));    
  }
	
}

It creates the batch in the databse, but when it gets to drush_backend_batch_process() it doesnt execute the batch.

In batch_6.inc I checked if the correct id is submitted and it is.

function _drush_backend_batch_process($command = 'batch-process') {
  $batch =& batch_get();

  if (isset($batch)) {
    $process_info = array(
      'current_set' => 0,
    );
    $batch += $process_info;

    // Initiate db storage in order to get a batch id. We have to provide
    // at least an empty string for the (not null) 'token' column.
    db_query("INSERT INTO {batch} (token, timestamp) VALUES ('', %d)", time());
    $batch['id'] = db_last_insert_id('batch', 'bid');

    // Actually store the batch data and the token generated form the batch id.
    db_query("UPDATE {batch} SET token = '%s', batch = '%s' WHERE bid = %d", drupal_get_token($batch['id']), serialize($batch), $batch['id']);

    $finished = FALSE;

    while (!$finished) {

//The $batch['id'] is what it should be
//The command outputs "batch-process"

      $data = drush_backend_invoke($command, array($batch['id']));

//$data outputs false

      $finished = drush_get_error() || !$data || ($data['context']['drush_batch_process_finished'] == TRUE);
    }
  }
}

I have no idea what I m doing wrong at this point, wouldnt this be like typing: "drush batch-process 5". (btw I tried that and that works)
Can you give me a clue please? Thanks in advance.

It must have been something with the windows drush. I tried it on a linux machine and everything works. Still dont know what the cause is, but since production will be on a linux machine its not an issue for me anymore.

Awesome work, xjm. Thanks.

Deleted some spam that changed the title of this issue. Should have recovered the title first, it appears.