$ b $ f $ f basename（f）
＃[1]file


Unfortunately I suck at regexp. If I have a path like so:

/long/path/to/file, I just need to extact file.

If someone supplies file/ I just need file.

If someone supplies /file/, I still need just file.

I've been using stringr functions as a crutch but this seems like straight up grep territory. Help, please?

If I understand correctly, you could use the basename function.

f <- "/long/path/to/file"
basename(f)
# [1] "file"