Remove "submitted by" text on teaser only
That setting is checked and the information added in template_preprocess_node().

Which means that there is no other way than a preprocess function to change this. However, there is nothing stopping you from adding a preprocess function to a module, that works perfectly fine. You just need to make sure that your module runs after node.module by setting the weight in the system table to something higher than node (probably 0).

Code example by will:

In your .install file:

db_update('system')
  -&gt;fields(array('weight' =&gt; 1))
  -&gt;condition('type' =&gt; 'module')
  -&gt;condition('name' =&gt; 'moduleName')
  -&gt;execute();


And then in the .module file:

function moduleName_preprocess_node(&amp;$variables) { 
  // Do not display post information on teasers
  if ($variables['teaser']) {
    $variables['display_submitted'] = FALSE;
  }
}