Moodle files can be used in multiple courses.
They are owned by a user.
mysql -u $mddbuser -p$mddbpass -e "use $mddbname;select id,userid,contenthash,filename,filearea,filesize from mdl_files" > moodlefiles.txt
contenthash value is really the location in moodledata/filedir/ as well as
the name of the file.
'SoS', Ken