Determine whether a particular file is compressed

Write a .7z, .tgz, .zip or other compressed archive file.

Bonus: you can read it anywhere.

Downside: it can be slow if you have a lot of files.

Use avfs to access files inside the archive transparently.

mountavfs
mount /dev/my_flash_drive /media/flash0
rsync -au mydata/foo/ ~/.avfs/media/flash0/archive.tgz\#/foo/
umount /media/flash0

Look at the output without piping to wc to see the difference

$ ls -R www | cat
www:
dir1
dir2
file1

www/dir1:
file1

www/dir2:
file1
file2
$ ls -R www | wc -l
11

And

$ tar xvfz www.tar.gz
www/
www/dir1/
www/dir1/file1
www/dir2/
www/dir2/file1
www/dir2/file2
www/file1
$ tar xvfz www.tar.gz |wc -l
7

ls -R just produces some more output.