If you really want to output arrays from C, you need to push your items on the stack.

Right, that's the ticket. This seems to work the way I want:

#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>

void
readdir_inode(dirname)
     char*    dirname
INIT:
  struct dirent *ent;
  DIR* dir;
  SV* record[2];
  AV *entry, *ret_val;
PPCODE:
  dir = opendir(dirname);
  if (dir) {
    while ((ent=readdir(dir))) {
      printf("%ld %x\n", ent->d_ino, ent->d_name);
      record[0] = newSVpv(ent->d_name, 0);
      record[1] = newSViv((IV)ent->d_ino);
      PUSHs(newRV_noinc(av_make(2, record)));
    }
    closedir(dir);
  }
[download]

At least, I hope that last "newRV_noinc" shouldn't be a "newRV_inc"!