If you are used to the Windows (DOS) tree command as a way to getting a complete, opened, list of folders and the folders & files they contain -- then good news.
tree exists on Linux as well.
$ tree
As always, try --help to see the various parameters available for tree.
$ tree --help
Just a few examples are:
-q Print non-printable characters as '?'.The last one there, -h, is pretty interesting as it includes a concise size of the file or folder on each line.
$ tree -h
In just a bit of info to store for later ... tree also has a -X parameter, which returns an XML representation of your files. This XML list can then be pulled into other applications or reports.
$ tree doc -X