Quick edit many SKU fields in Drupal Commerce
An alternative way of doing this is as follows:


Create a view for the products including SKU &amp; Product Id (assigned by drupal commerce)
Export the view into a csv using the views_data_export module.
Amend your SKUs in the csv file using any text editor. This should make it easier to amend.
Create a feeds importer, with settings "Update existing commerce products", and using the "Product Id" as unique key (instead of SKU).
Load the amended csv to update the SKUs in the database.