I feel like I must be missing something simple, but for the life of me I cannot figure out how to clear a text file to just be blank.

Deleting the file and re-creating it is my usual solution, but in this case it will not work because the users that need a cleared out file only have access to this file specifically. If they delete the file, they do not have rights to create a new one. Modifying rights on this folder is not an option, either.

Any ideas?