For all content types in drupal

for_all_content_types_in_drupal.sh

#!/bin/bash                                                                                                                                    
drush sqlq "select type from node_type" | while read content_type;
do
   echo "Changing comment settings for $content_type"
   drush vset comment_default_mode_$content_type 0
   drush vset comment_default_per_page_$content_type 50
   drush vset comment_$content_type 2
   drush vset comment_form_location_$content_type 1
   drush vset comment_preview_$content_type 0
   drush vset comment_subject_field_$content_type 0
   # or do whatever with individual element of the array
done