newbie q - lightweight dirname of file path?

[Daire Byrne]

Hi,

Apologies for such a newbie question, but I have been searching for a
solution to this all day and it's starting to drive me crazy.

I have a really simple probe to tell me filenames:

probe syscall.open, syscall.openat, syscall.stat {
    printf("%s\n", filename_unquoted)
}

But actually what I want, is the full directory path that each file is
in. So a lightweight way to do it would be similar to the "dirname"
bash command and just chop off only the last entry seperated by the
"/".

I think there may also be a way to do it by looking up the inode data?
I was really hoping for a fast lightweight way to do it (like text
processing the filename string).

Ultimately, I want to trace millions of file lookups but only store
and print out their directory locations rather than do that in
userspace (if possible).

Cheers,

Daire