Working on SEO, I have a client site that has hundreds, maybe thousands, of images uploaded.
I have crawled the site with Screaming Frog SEO spider and have segmented crawl data to list all images in use on the site and I have downloaded a local copy of the folder where the images are uploaded.
I don't need to compare the actual files just 2 lists of the names of all files (these or other files, tasks like this are fairly common for me).
I'm comfortable with Sublime Text (and its multiple cursors and advanced find and replace functions) and I'm familiar with command line tools like
grep. (Mac user)
I assume that the first step would be to eliminate duplicates within each list, and then compare the lists which would yield a list of files which are in both "list 1" and "list 2" and/or which are not in "list 1" but are in "list 2."