How can I filter the results of 'git fsck --unreachable'

I'm trying to look for unreachable commits that use certain file somefile.jsx, say. Can I do that? Or can I look for ones that contain a certain specific in one of the files? The deeper problem I have hundreds of unreachable commits there's one I'm looking for ..

1. Run git fsck --unreachable --no-progress to get just the lines with the commit info.
2. Grep it for just commits, grep 'unreachable commit'.
3. Pipe it to cut -d' ' -f3 to get the commit it (the 3rd field).

Putting that all together...

git fsck --unreachable --no-progress | grep 'unreachable commit' | cut -d' ' -f3

Now you have a list of all the unreachable commits. Put that in a file.

You can run git --no-pager log --format=oneline -n1 --stat <commit id> on each of them to see what files they changed. Here's a little Perl one-liner to do that.

perl -nwle 'system "git --no-pager log --format=oneline -n1 --stat $_"' <commit file>

You can even grep for "WIP" to find old stashes.