process_file_name: Processes a file name to make sure it is valid and has the correct suffix and extension
File names with an extension (e.g. ".XPT") are not altered
Description
Processes a file name to make sure it is valid and has the correct suffix and extension
File names with an extension (e.g. ".XPT") are not altered
Usage
process_file_name(file_name, year, extension = ".XPT")
Arguments
file_name
name of the file