I'm trying to figure out a way to compare all the files of a certain type (let's call it .mp3 for sake of this example) on one drive with all the .mp3 files on another drive. Based solely on filenames I want to find files on DriveA that do not exist on DriveB. The file path does not matter at all.

So, if there is a file "foo/bar/file10.mp3" on DriveA and a file "zap/dap/map/file10.mp3" that file will be omitted from the results because "file10.mp3" exists on both drives.

So using the commands:

find DiveA -name "*mp3" > DriveA.txt
find DiveB -name "*mp3" > DriveB.txt

I can get a list of all the files and pathnames for DriveA and then for DriveB. But I can't figure out how then take those two lists and create a new list of pathnames for files that exist on DriveA but do not exist on DriveB.

I just want to use the filename to compare, not the pathname. I'm imagining there is some way to use diff to isolate the unique filenames but I'm not really sure – a little beyond my skillset.

Filenames/paths also can have spaces in them so piping the results through basename has been difficult for me, though even if I figured that out I'm not sure what I would do next!

Any help appreciated!

EDIT: /u/gumnos seems to have a winner with this use of the awk command:

$ awk -F/ 'FNR==NR{b[$NF]=$0; next} !($NF in b)' DriveB.txt DriveA.txt

Works for me on initial testing. I put one unique file out of a few hundred on my test folders and this picked it out.