I'll try to do those suggestions and see what happens next.

About substr, I am already using it... so I'm not sure what do you mean by using it to emulate the C pointer. Even though I'm modifying the original buffer, I would expect that I would get at least the first entry correctly... I played around with unpack, but my guess is that I just don't have the same data on the perl buffer (neither identify what is being available over there, my guess is that I missing a long integer.

This is to solve a very specific problem with NFS exports: some directories got clobbered with so many files (above 300k) that even listing them with ls takes a lot of time. Unfortunately, I don't have root access to evaluate what is going over there, but using getdents allow me to get the list of files much more quickly.

That's what I need in most cases (I'll simply remove the files from there, no need to stat them.readdir() presents the same issues as ls.